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Abstracts of Papers Presented at the Human
Behavior and Evolution Conference, June, 1995, Santa Barbara, CA
University of California, Santa Barbara
June 28-July 2, 1995
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Sessions:
Evolutionary Ecology and Optimality Analyses.
Evolution & Cognition I.
Evolutionary Psychiatry I.
Darwinian Aesthetics: Human Beauty
Computational Human Evolution: From Artificial Life to Artificial Human Evolution
Arts & Cultural Processes
Evolutionary Psychiatry II.
Status, Competition, and Coalitions
Environmental "Mismatch", Stress, and Pathology
New Investigator Award plus Evolution & Cognition
Birth Order, Investment, & Family Dynamics.
Evolutionary Ecology II.
Love, Female Choice, & Mating Strategies
Literature & Arts.
Evolution & Law I.
Infidelity & Mating Conflict.
Evolution & Ethnology
Evolution & Law II.
Evolution, Politics, & Society.
Risk & Violence.
Development & Parental Investment.
Evolution of Human Culture
Menstruation & Concealed Ovulation / Medicine.
Mindreading & Memory.
Behavioral Genetics / Pedagogy.
Poster Session.
Human Behavior & Evolution Society Program
University of California, Santa Barbara
June 28-July 2, 1995
Thursday, June 29
9:00 Plenary Address. David Haig (Museum of Comparative
Zoology, Harvard) Genetic conflicts in human pregnancy
Session 1-A. Evolutionary Ecology & Optimality Analyses.
 | 10:10 Hill, K. The Cost of Reproduction: Is Intermediate Fertility Ever Optimal?
| 10:35 Towner, M. A Dynamic Model of Human Dispersal in a Land-Based Economy
| 11:00 Abbot, J. & Barrett, L. Women and Fuel in Malawi: Optimal Foraging?
| 11:25 Wara, A., Roskaft, E., & Djupvik, A. Reproductive Success in Relation to Resource-Access
in Two Different Parishes in Central Norway During the Period
1700-1900
| 11:50 Carey, A. Modernization's Effects on the Mortality Costs of Reproduction
| | | | |
Session 1-B. Evolution & Cognition I.
| 10:10 Fiddick, L., Cosmides, L. & Tooby,
J. Does the Mind Distinguish between Social Contracts and Precautions?
| 10:35 Ketelaar, T. Emotion as Mental Representations of Fitness Affordances I:
Evidence Supporting the Claim that Negative and Positive Emotions
Map onto Fitness Costs and Benefits
| 11:00 Ketelaar, T. Emotion as Mental Representations of Fitness Affordances II: Does Anger Make You More Rational?
| 11:25 Sugiyama, L., Tooby, J. & Cosmides, L. Testing for Universality: Reasoning Adaptations among the Achuar of Amazonia
| 11:50 Fetzer, J. Heuristics, Evolution, and Rationality
| | | | |
Session 1-C. Evolutionary Psychiatry I.
Session 2-A. Darwinian Aesthetics: Human Beauty.
| 2:45 Singh, D. & Suwardi, L. Men's Preference for Romantic Relationships: Pretty Faces or Beautiful Bodies?
| 3:10 Johnston, V.S. & Oliver-Rodriguez, J.C. Mirror, Mirror, On The Wall...
| 3:35 Gangestad, S. & Thornhill, R. Human Sexual Selection, Developmental Stability, and Indicator Mechanisms
| 4:00 Palameta, B. & Martin, S. Male Perceptions of Female Attractiveness: The Importance of Waist-to-Hip Ratio
| 4:25 Quinsey, V. & Lalumihre, M. Pedophilia and the Design of Male Sexual Age and Gender Preferences
| | | | |
Session 2-B. Computational Human Evolution: From Artificial
Life to Artificial Human Evolution.
Session 2-C. Arts & Cultural Processes.
Session 2-D. Evolutionary Psychiatry II.
| 2:45 Sloman, L. & Hilburn-Cobb, C. Attachment Theory and the Involuntary Subordinate Strategy
| 3:10 Beahrs, J. Regressive Stabilization in Human Individuals and Societies
| 3:35 Gardner, R. & Joiner, T. Basic Plans and the Biology of Leadership
| 4:00 Brown, R.M., Dahlen, E. Mills, C., Ricks, J. & Biblarz,
A. Evaluation of an Evolutionary Model of Self-Preservation
| 4:25 Keckler, C. Modeling Stress and Arousal as Adaptations
| 5:05 Plenary Address. Vernon Smith (with Hoffman & McCabe)
(Economic Science Laboratory for Research and Education, University
of Arizona):
Behavioral foundations of reciprocity: Experimental economics and evolutionary psychology
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Friday, June 30
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| 9:00 Plenary Address.
Frank Sulloway (Massachusetts Institute of Technology): Birth order & evolutionary psychology: A meta-analytic overview
| | | | | | |
Session 3-A. Status, Competition, & Coalitions.
| 10:10 Buss, D. Human Prestige Criteria
| 10:35 Stone, V. & Kussmaul, C. Models of Intraspecific Competition: Strategies for Social Climbing
| 11:00 Patton, J. Status, Warriorship, and Alliance in the Ecuadorian Amazon
| 11:25 Kurzban, R., Tooby, J. & Cosmides, L. Detecting Coalitions: Evolutionary Psychology and Social Categorization
| 11:50 Boehm, C. Evolution of Egalitarian Behavior
| | | | |
Session 3-B. Environmental "Mismatch", Stress, & Pathology.
Session 3-C. Evolution & Economics. (Organizer: Bergstrom)
Session 4-A. New Investigator Award plus Evolution & Cognition II.
Session 4-B. Birth Order, Investment, & Family Dynamics.
| 2:45 Davis-Walton, J. Born Too Late?: Parental Investment and Birth Order in Modern Canada
| 3:10 Somit, A., Peterson, S. & Arwine, A. Birth Order and Political Behavior: A Sex Related Effect
| 3:35 McAndrew, F. & Cooley, J. Birth Order and the Naming of Children:
An Examination of Naming as a Strategy of Parental Investment.
| 4:00 Daly, M., McConnell, C. & Glugosh, T. Parent's Knowledge of their Children's Beliefs and Attitudes:
An Indirect Assay of Parental Solicitude?
| 4:25 Barber, N. Effects of Parental Divorce on Sexual Strategies of Children
| | | | |
Session 4-C. Evolutionary Ecology II. (Organizer: Mace)
| 2:45 Mace, R. Reproduction and Heritable Wealth in Nomadic Pastoralists
| 3:10 Abbot, J. Do Children Pay Back Their Own Costs?
| 3:35 Sellen, D.W. Child Growth as a Proxy for Fitness Differentials among Polygynous Datoga
| 4:00 Biran, A. Child Care in a Population of Maasai Agro- Pastoralists
| 4:25 Bichakjian, B. The Nature of Language and its Biological Underpinning
| 5:05 Plenary Address.
Steven Pinker (Dept of Brain & Cognitive Sciences, MIT): The Language Instinct
| 7:30 Keynote Address. Richard Dawkins (Dept. of Zoology, Oxford
University):
Animal Models of Past and Present Worlds
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Saturday, July 1
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| 9:00 Plenary Address. John Hartung (SUNY Brooklyn Medical
School): A Light Unto The Nations: Judeo-Christianity, Morality, & Group Selection
| | | | | | | |
Session 5-A. Love, Female Choice, & Mating Strategies
Session 5-B. Literature & Arts. (Organizer: Scalise Sugiyama)
Session 5-C. Evolution & Law I. (Organizer: Goodenough)
| 10:10 Grady, M. Products Liability and Evolution
| 10:35 Fisher, H. Human Divorce Patterns:
How Neural Mechanisms in the Brain Influence Divorce and Interact
with American Divorce Law
| 11:00 Rodgers, W. Deception, Self-Deception and Myth: Settlement of Complex Environmental Disputes
| 11:25 McGuire, M. Comparative Studies of Uncertainty and the Law
| 11:50 Masters, R. Kin Recognition, Emotion, and Ethnocentrism
| 1:35 Plenary Address. Pascal Boyer (C.N.R.S., Lyon, France):
Adapted Mind, Evolved Ontology, and Acquired Culture
| | | | | |
Session 6-A. Infidelity & Mating Conflict.
| 2:45 Brown, S. & Kenrick, D. Paternal Certainty and Female Dominance: Should Males Prefer Submissive Females?
| 3:10 Shackelford, T. & Buss, D. Cues to Infidelity
| 3:35 Buunk, B. & van en Eijnden, R. Context Effects on Willingness to Engage in Extrapair Copulations
| 4:00 Ast, D. & Gross, M. Status Dependent Sexual Deception: Which Men Lie?
| 4:25 Heilmann, M. If We All Want Honest Mates, Why Do We Deceive Them Constantly?
| | | | |
Session 6-B. Evolution & Ethnology.
Session 6-C. Evolution & Law II.(Organizer: Goodenough)
Session 6-D. Evolution, Politics, & Society.
------------------------------------------------------------------------
Session 7-A. Risk & Violence.
| 9:00 Dyson-Hudson, R. & Dyson-Hudson,
N. South Turkana Homicide: A Proximate View
| 9:25 Walker, P. Documenting Patterns of Violence in Earlier Societies: The
Problems and Promise of Using Bioarchaeological Data Testing Evolutionary
Theories
| 9:50 Wilson, M. & Daly, M. Risk-taking and Homicide
| 10:15 Atzwanger, K. Biological Aspects of Aggressive Driving Behavior
| 10:40 Lewis, B., Linder, D., & Kenrick, D. Arousal and Attraction: Reproductive Potential Versus Threat Assessment
| | | | |
Session 7-B. Development & Parental Investment.
Session 7-C. Evolution of Human Culture.(Organizer: Palmer)
Session 8-A. Menstruation & Concealed Ovulation / Medicine.
Session 8-B. Mindreading & Memory.
| 11:20 Johnson, C. Cognition in the Wild: Gaze-Mediated Social Interaction in Pygmy Chimpanzees
| 11:45 Stone, V. Neurological Models of Facial Expression Recognition
| 12:10 Tooby, J. & Cosmides, L. The Evolution of Memory, Modularity, and Information Integrity
| 12:35 Cosmides, L. & Tooby, J. Episodic Memory, Theory of Mind, and their Breakdown
| 1:00 Schmidt, K. L. & Allen, J. S. Schizophrenia and Nonverbal Social Behavior in Papua New Guinea
| | | | |
Session 8-C. Behavioral Genetics / Pedagogy.
| 11:20 Rowe, D. & Vazsonyi, A. Between and Within Sex Variation: Are the Causes Alike?
| 11:45 Burgess, R. & Molenaar, P. Evolution, Development, & Chaos: The role of nonlinear epigenetic processes
| 12:10 McDonald, K. Eugenics as a Component of Judaism as a Group Evolutionary Strategy
| 12:35 Squires, A. Selective fosterage, impulse to teach, and gene/culture interaction
| 1:00 Shellberg, T. Filling Two Voids with One Clone: Teaching Freshmen Evolution and Behavior
| | | | |
List of Posters (Alphabetical by first author):
| Anderson, J. & Crawford, C. Costs and benefits of female infanticide in an uncertain world
| Anderson, J. & Crawford, C. Socioecological correlates of son and daughter preference: A cross-cultural analysis
| Brown, W. & Palameta, B. Altruism facilitates the formation of social support networks
| Flood, A. & Crawford, C. A re-examination of Singh's waist-hip ratio figures: A check of validity and generalizability
| Gorry, A. Intergenerational female competition: Older
women's attempts to manipulate the reproductive interests of younger
women
| Harms, W. A scheme for formalizing evolutionary epistemology
| Hasegawa, T., Hiraiwa-Hasegawa, M., & Kajikawa, S. Chimpanzee males cry pant-hoots for power
| Janicki, M. Detecting helpers and non-helpers: Their importance in reasoning about social exchange
| Kemmerer, D. & McNamara, P. Parent-offspring conflict as a selection pressure for the evolution of early language acquisition
| LaRue, L. Evolved fur attractiveness
| Lindberg, T., Crawford, C. & McFarland, C. The frequentist reasoning hypothesis: How significant is the effect?
| Mealey, L. Evolution of sociopathy
| Mills, M. An experimental publication utilizing the Web
to facilitate scholarly communication and peer review: The Journal
of Evolutionary Psychology
| O'Meara, T. Causation and the tabula rasa mind
| Pound, N. Sexual jealousy and mate retention tactics
| Roswell, L., Woods, S. & Bailey, K. Disorder profiling: Anorexia nervosa and bulimia nervosa
| Salmon, C. Closeness, identity, and social relationships
| Scheib, J. Mate selection theory: investigating women's choices of donors at a Canadian sperm bank
| Segal, N. & Blozis, S. Bereavement in monozygotic and dizygotic twins: An evolutionary perspective
| Semeniuk, R. & Crawford, C. The relationship of psychological health and differential parental investment in humans
| Stewart, S., Krajnak, K. & Lee, T. Effects of photoperiod on ovulation in the female meadow vole
| Surbey, M. & Nagata, B. Human mate selection: When big and brawny isn't always better
| Tilley, C. & Palmer, C. Sexual access to females as a motivation for joining gangs
| Walters, S. Fluctuating asymmetry as a measure of human developmental stability
| | | | | | | | | | | | | | | | | | | | | | | |
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Abstracts of Papers Presented at the Human Behavior and Evolution
Conference, June, 1995, Santa Barbara, CA
Animal Models of Past and Present Worlds
Richard Dawkins
Department of Zoology,
Oxford University
An animal is a model of its world. More precisely, because of
the way natural selection works, ananimal is a composite model
of the worlds of its ancestors, and its DNA is a digital description
ofthe environments in which its ancestors survived. At the same
time and in a different language, theanimal's nervous system can
be read as a description of present and past worlds. Brains construct,and
continuously update, virtual reality models of the world. Highly
social and cultural animalsmove through a partially shared virtual
world. Genes are selected to survive, not just in the realworld,
but in the virtual worlds synthesized in brains.
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Genetic Conflicts in Human Pregnancy
David Haig
Museum of Comparative Zoology,
Harvard University
26 0xford Street,
Cambridge MA 02138
Pregnancy has commonly been viewed as a cooperative interaction
between a mother and her fetus. However, the effects of natural
selection on genes expressed in fetuses may be opposed bythe effects
of natural selection on genes expressed in mothers. In this sense,
a genetic conflict canbe said to exist between maternal and fetal
genes. Fetal genes will be selected to increase thetransfer of
nutrients to the fetus, and maternal genes will be selected to
limit transfers in excess ofsome maternal optimum. Thus, a process
of evolutionary escalation is predicted in which fetalactions
are opposed by maternal countermeasures. The phenomenon of genomic
imprinting meansthat a similar conflict exists within fetal cells
between genes that are expressed whenmaternally-derived and genes
that are expressed when paternally-derived. My talk will review
evidence for both kinds of conflict.
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The Natural Origins of Understanding Other Minds
Alan M. Leslie
Rutgers University Center for Cognitive Science
Psychology Building,
Busch Campus,
Piscataway, NJ 08855-1179
One of the most remarkable conceptual achievements of young children
is recognizing mentalstates in other people (so-called "theory
of mind"). This ability, which is probably a speciescharacteristic,
constitutes a major upgrade over infra human social exchange.
There are at least three basic mental states that are recognized
early in development: believing, desiring, and pretending. A cognitive
model must account for how young children are able (a) to attend
tomental states in the first place, and (b) subsequently to learn
more about them. More than tenyears ago, I outlined a model which
postulated the existence of what came to be called the Theory
of Mind Mechanism (ToMM). There were two key claims. First, normal
development in thisdomain depends upon a specialized (and probably
innate) data structure (the"metarepresentation") that
is functional at least by the end of the second year of life.
Second,children with the neurodevelopmental disorder known as
autism suffer a specific impairment toToMM which deprives these
children of a normal social life. Since then a wealth of experimentaldata
has accumulated which supports and extends the theory of ToMM.
I will outline some ofthese theoretical ideas and dip into some
of these data.
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Behavioral Foundations of Reciprocity: Experimental Economics
and Evolutionary Psychology Vernon Smith
Economic Science Laboratory,
University of Arizona,
Tucson, AZ 85721,
Smith@econlab.arizona.edu
Laboratory experiments generally support the proposition that
in private property regimes noncooperative behavior in large group
markets yields efficient social outcomes.Experiments, however,
regularly fail to support noncooperative predictions in small
group anonymous interaction games, and public good environments.
Thus, subjects in the latterfrequently achieve more efficient
outcomes -- they collect more money from the experimenter -- than
noncooperative theory predicts. Subject behavior exhibits a "habit
ofreciprocity" even in single play games. We present the
results from a variety of suchexperiments, and relate them in
a preliminary way to the work of evolutionary psychologists.Our
objective is to develop a research program that would combine
the evolutionary and experimental economics themes. (Paper by:
Elizabeth Hoffman (Iowa State University), KevinMcCabe (University
of Minnesota), & Vernon Smith)
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Birth Order and Evolutionary Psychology: A Meta-analytic Overview
Frank J. Sulloway
Massachusetts Institute of Technology,
Program in Science,
Technology and Society.
Building E51-006,
Cambridge, MA 02139
Research in behavioral genetics has established that siblings
are surprisingly different in theirpersonalities. These findings
indicate that nonshared family influences play a much greater
role inpersonality development than do shared influences. Birth
order -- a nonshared influence -- isimportant in personality development
because it creates systematic differences in the familyexperience.More
than a thousand publications exist on the topic of birth order
and personality. Some psychologists have criticized this research
as being poorly designed, laden with artifacts, andgrossly inflated
in its claims. A meta-analytic review of this literature shows
otherwise: Significant birth-order differences exist for each
of the Big Five personality dimensions. Strategic differences
in sibling behavior are visible most clearly during periods of
intense social conflict. These differences are consistent with
a Darwinian perspective on sibling strategies, including the role
of competition for parental investment.
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The Bathwater and the Baby : What the Culture Concept Can and
Cannot Do for Human Behavioral Ecology
Lee Cronk
Department of Anthropology,
Texas A&M University College Station,
Texas 77843-4352
Among cultural anthropologists, "culture" amounts to
a one-word theory of behavior: people dowhat they do because their
culture makes them do it. However, as research by many HBESmembers
has shown, much human behavior can be understood without reference
to culture.Empirically, culture often utterly fails as an explanation
of behavior because people routinely failto follow its dictates.
On the other hand, culture is pervasive in human affairs and truly
makeshuman social life quite different from social life for other
species. How best, then, to incorporatethe concept of culture
into human behavioral ecology? Two existing approaches to this
question,the cultural and reproductive success hypothesis and
cultural transmission models, are alsoweakened by discrepancies
between culture and behavior. Another way to incorporate culture
intohuman behavioral ecology is to see it as the context of human
action and as a tool people use insocial manipulation. The study
of signal systems is a key to an understanding of socialmanipulation
and to the incorporation of culture into human behavioral ecology.
Examples of thismanipulation of culture for reproductive benefit
include Yanomamo kin term manipulation and thederogation of sexual
competitors. The human behavioral ecological study of social manipulationin
cultural contexts needs to be expanded. Audience effects are one
phenomenon that might becreatively used in the field to explore
such issues.
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The Language Instinct Steven Pinker Department of Brain &
Cognitive Sciences,
MIT
Cambridge, MA 02139
What is the evolutionary status of human language? I discuss how
language works, how it isdistributed among people and societies,
and how it may have evolved. In particular, I presentevidence
that language (a) is built on two principles: A dictionary of
memorized symbols, and aset of generative rules organized into
several modules; (b) reliably develops throughout thespecies across
a wide range of environments, largely independent of general intelligence,
andtherefore seems to be an innate specialization; has no known
homologues in other living primate species; and (d) is a product
of gradual natural selection for the communication of propositional
messages.
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A Light Unto The Nations : Judeo-Christianity, Morality &
Group Selection
John Hartung Department of Anesthesiology,
State University of New York Health Science Center at Brooklyn,
New York 11203 (Hartung@medlib.hscbklyn.edu)
Understanding natural selection should result in the realization
that humans have no more inherentpropensity to be moral than do
cats, dogs and blue-green algae. Nevertheless, people whoseunderstanding
of natural selection is or was otherwise admirable, including
A. R. Wallace, C.Darwin, V. C. Wynne-Edwards, and a growing number
of HBES stalwarts, have put forth modelsand conjectures which
enable them to perceive human nature as either inherently moral
orcomprised of naturally selected components that serendipitously
generate morality. These effortsare made, in part, because they
bolster hope for advancing morality by inferring or assuming that
anatural foundation for morality already exists and merely needs
to be built upon -- a hope that ishoped will become a self-fulfilling
prophecy.Empirical support for inherent morality is often gleaned
from the observation that humans naturally generate religions
and those religions approach or equal Judeo-Christianity as a
forcewhich, at least in its original intent, advances morality.
Unfortunately, the illusion that Judeo-Christianity was originally
other than a scheme to magnify, through group cooperation, theinherent
selfishness and amorality of Jews and Christians, is based upon
commonly perpetrated misreadings of The Holy Scriptures. Because
false hope jeopardizes true hope, attachment to thisillusion,
and to intellectual contrivances which explain it and other presumptive
evidence ofinherent morality, threatens the very endeavor which
it seeks to advance. Motivated by thatrealization, and the realization
that morality can be, and can only be, accomplished by humandesign,
a more sober reading of The Bible will be presented.
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Adapted Mind, Evolved Ontology and Acquired Culture
Pascal Boyer C.N.R.S.M.R.A.S.H.,
14 av. Berthelot 69363 Lyon, France
Cultural acquisition does not involve much active "transmission"
of contents, nor does it imply acontent-independent capacity for
"imitation" of behavior. Cultural representations are
mostlyacquired by attending to particular cues and deriving content-specific
inferences from them. Thecore architecture underlying early conceptual
development can be construed as an "evolvedontology"
which directs those inferences. It consists of specialized inference
engines which areonly triggered by particular aspects of the natural
and social environment. Domain-specificengines make certain types
of cultural representations more likely than others to be acquired.
Thisaccounts for the stability and recurrence of those representations
in acquired culture. The pointapplies not only to domains such
as kinship categories or naive theories of the natural world,
buteven to apparently "unconstrained" domains like religious
categories.
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From the Neanderthal to the Modern Mind (or how evolutionary psychology
and human ecology need Paleolithic archaeology)
Steven Mithen Department of Archaeology,
University of Reading, U K
Attempts to identify the critical features of the modern mind
often rely upon comparisons with ourclosest living relative, the
chimpanzee. Comparisons are made, for instance, with regard to'linguistic'
and toolmaking capacities in the belief that these will help us
understand how our ownabilities in these areas evolved. Unfortunately
these comparisons are of little value as over 6million years have
elapsed since modern humans and chimpanzees shared a common ancestor.More
useful comparisons can be made with the minds of recent, but extinct,
relatives, such as H.erectus, archaic H. sapiens and H. neanderthalensis.
This requires the development of acognitive archaeology. I argue
that by using the theoretical structure of evolutionary psychologysubstantial
progress can indeed be made in elucidating the cognitive architecture
of extincthominids, which in turn brings the defining feature
of the modern mind into sharper focus. This feature appears to
be one of effortless fluidity between cognitive domains which
had originallyevolved as specialized and relatively independent
modules. While this cognitive fluidity -dependent upon a series
of specialized cognitive domains - leads to the remarkable adaptivesuccess
of modern humans epitomized by global colonization, as well as
our achievements in boththe sciences and arts, it also appears
responsible for the less appealing aspects of human nature,such
as a propensity for racist thinking in certain socioeconomic contexts.
Moreover, while the evolution of a cognitively fluid mentality
can be explained by reference to biological evolution, its existence
seriously complicates attempts to explain modern behavior by the
use of evolutionary theory. Evolutionary psychologists and human
ecologists need to know a little Paleolithicarchaeology!
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Women and fuelwood in Malawi: optimal foraging?
Joanne Abbot and Louise Barrett
Dept of Anthropology,
UCL,
Gower St, London WC1E 6BTE
mail: j.abbot@ucl.ac.uk
Data are presented for women's fuelwood collection from Lake Malawi
National Park. Acost-benefit analysis is used to determine the
interplay between ecological constraints, behavioraldecisions
and risk factors (the penalties incurred for illegal resource
use). Optimality modeling isused to analyze the decision making
associated with the observed patterns of women's fuelwoodcollection.
The implications of this research for the conservation of forest
resources areaddressed.
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The Tragedy of the Moderns: From Prudent Predators To Tragic Despoilers
Wayne E. Allen
Department of Anthropology
University of California - Santa Barbara,
CA 93106
e-mail: 6500wea@ucsbuxa.ucsb.edu
Discussions of biophilia and resource sustainability frequently
invoke indigenouspeoples as exemplars of these phenomena, often
with little scientific explanation ofthe evolutionary mechanisms
or processes involved. Darwinian evolution, formal microeconomics
and optimal foraging theory are predicated on the assumption thatindividuals
are self-interested. Hardin (1968) stated that when confronted
withresources in an "open-access commons," individuals
should pursue their self-interests to a point that eventually
results in a "tragedy of the commons." Hardinfailed
to take into account, though, inclusive fitness and the possibility
that theactors utilizing the commons might all be kin. My research
among the Dene of northern Canada reveals that prudent predation
of a commons is possible as longas the necessary propinquity conditions
(social & spatial) are present for thecalibration of evolved
behavioral mechanisms during ontogeny. Hardin's characterization
is apt for a human nature that has been calibrated by modernurban
contexts where most exchanges occur between strangers, but not
one thatwas typical of our species for 99% of our evolution in
hunter-gatherer socioecological contests
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Costs and benefits of female infanticide in an uncertain world.
Judith L. Anderson and Charles B. Crawford
Department of Psychology,
Simon Fraser University
Burnaby, British Columbia V5A 1S6,
Canada e-mail: judith_anderson@SFU.CA
The rationale for female infanticide is often assumed to be increased
production of sons, resulting in an improvement in parental "utility"
(usually fitness). The goals of this study were (1)to identify
the conditions under which numbers of sons are most efficiently
increased by female infanticide,compared with the fitness costs
of infanticide, and (2)to investigate the consistency of outcomesof
infanticide, given stochasticity in production, sex, and survival
of subsequent offspring. UsingMonte Carlo simulation, we found
that benefit/cost ratios are influenced strongly by sex-specific
juvenile survival and fertility characteristics of the mother.
At rates of female infanticide between.1 and .4, stochastic factors
produce highly variable outcomes. We conclude that the assumption
simplicit in optimality hypotheses concerning female infanticide
should be examined carefully.
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Socioecological correlates of son and daughter preference: A cross
cultural analysis
Judith L. Anderson and Charles B. Crawford
Department of Psychology,
Simon Fraser University
Burnaby, British Columbia V5A lS6,
Canada e-mail: judith_anderson@SFU.CA
The goal of this analysis was to identify socioecological characteristics
of cultures that predictparental sex bias in the Standard Cross
cultural Sample. Independent variables included measuresof sexual
selection on males, economic contributions of women, types of
warfare, familyboundaries, value of children, and participation
of women in public life. Dependent variablesincluded psychological
and behavioral measures of parental sex bias. Though all the categories
ofindependent variables were correlated with some measures of
parental sex bias, warfare andfamily boundaries variables produced
the widest associations. Attitudes toward sons and daughters did
not consistently predict sex-biased parental behaviors. We conclude
that successfulapplication of sex allocation theory to humans
will require models of specific parental behaviorsrather than
generalizations about "parental investment".
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A model to test the paternity confidence hypothesis for concealed
ovulation
Kermyt G. Anderson
Department of Anthropology
kganders@unm.edu
University of New Mexico
Albuquerque, NM 87131
Hypotheses abound to explain the evolution of concealed ovulation
in humans. The paternityconfidence hypothesis, one of the most
widely cited, suggests that the trait evolved because itincreased
the paternity confidence of males to the extent that they were
selected to invest in theoffspring of their mates. A model is
developed to test this hypothesis, beginning with theassumption
that male and female strategies are frequency-dependent: the success
of a newstrategy depends on what other individuals in the population
are doing. The results of this modelsuggest that females with
concealed ovulation, and the males who mate with them, benefit
mostwhen they are at a relatively low frequency in the population.
At higher frequencies femalesbenefit less from concealed ovulation,
and are unlikely to invade the general population. These results
suggest that increased paternity confidence might not have been
the driving force behindthe evolution of concealed ovulation.
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Female reproductive synchrony and the emergence of male investment
C. Arthur and C. Power
Department of Anthropology,
University College London,
Gower St., London WC1E 6BT
e-mail ucsaccp@ucl.ac.uk
Extreme reproductive synchrony of females effectively guarantees
male parental investment sinceit reduces philandering opportunities
to zero. But for evolving female hominids, with high infantmortality,
strict birth synchrony would be a costly strategy. A simple model
(varying interbirthinterval, female reproductive lifespan, infant
mortality rates) is used to assess the costs ofsynchrony to females.
A strategy of seasonally based synchrony would incur low costs,
whilereducing payoffs to males of philandering. A second model
(varying group size, male rank, IBI and infant mortality) assesses
costs to males of pursuing fidelity or philandering strategies
where females randomize or synchronize (within birth season) their
reproductive cycles. Preliminary results suggest that female reproductive
synchrony would have been required to force theemergence of investment
by higher-ranking males.
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Status dependent sexual deception: Which men lie?
Debora Ast and Mart R. Gross
Department of Zoology,
University of Toronto
ast@zoo.utoronto.ca
Individuals in many species adopt alternative behavioral tactics
based on condition dependent decisions. This study examines the
status of males using two alternative tactics, honesty anddeception,
to obtain sex. In human society, our legal and moral systems are
designed to discourage tactics such as deception. Low and high
status males are predicted to be more likely touse deception than
middle status males, for whom the cost of violating moral rules
is greater. Our results from a university student survey support
this prediction. We also propose that emotional feedback following
different sexual behaviors provides an assay of the relative fitnessconsequences
of each behavior. We find that deceptive sex provides less positive
emotionalreturns for middle status males than for high and low
status males. Adherence to moral codes willbe facultative, based
on the status dependent net benefit an individual receives from
doing so.
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Biological Aspects of Aggressive Driving Behavior
Klaus Atzwanger
Ludwig-Boltzmann-Institute for Urban Ethology
c/o Human biology
Althanstr aBe 14, A- 1090
Vienna, Austria
Aggressive car driving seems to be one of the fields of industrial
societies, where aggressivebehavior is tolerated. Biological theories
predict more risk taking behavior in younger man than inwoman,
more aggression in anonymous situations, and dominance display
behavior of higherranking Individuals. In an empirical experiment,
drivers were videotaped when they drove upclose to another car.
Their gender, race, driving behavior and the type and value of
their car werecoded. Men drove close up faster than women. Individuals,
who drove alone, were moreaggressive than those who had others
joining them. Drivers of cars with higher status drove closerup
than others. Fast driving close up was used to drive away others.
Estimating ones social statusdepending on ones cars value seems
to lead to dominance behavior of car drivers.
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The epidemiology of "selfish" memes
Robert Aunger
Department of Anthropology
Northwestern University
rau806@lulu.acns.nwu.edu
Dawkins and Sperber (among others) have recently argued that cultural
beliefs can be seen as"mental viruses." Like RNA, such
beliefs are replicating chunks of information that spread epidemiologically
through inter-personal contact or via intermediary vectors such
as mass mediaIn this paper, I use the epidemiological approach
to describe the cultural evolution of food taboosin a population
of horticulturalists and foragers in Zaire. I call these beliefs
"selfish" because insufficient numbers they can reduce
their hosts' fertility (by causing nutritional deficits). Inparticular,
I investigate whether variability in the prevalence of food taboos
in this population is afunction of their virulence (i.e., nutritional
cost to the host). I then infer that the units oftransmission
are likely to be food-specific rules, based on the pattern of
interpersonal transmissionof these beliefs (as determined by phylogenetic
analysis). Finally, since interview recall dataexhibits variability
within food-specific taboo rules, I argue that the units of meaning
in such rules are smaller than the amount of information typically
transmitted between people. The idiosyncratic process of mentally
incorporating these multi-memes rules therefore might accountfor
the high degree of intra-cultural variation observed in this belief
system.
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Mismatch Theory and Paleopsychopathology
Kent G. Bailey
Virginia Commonwealth University
806 West Franklin Street
Richmond, VA 23284-2018
Mismatch theory is based on five basic assumptions: human nature
evolved in prior ancestral environments (EEAs), most human evolution
ceased with sapiens around 40,000 years ago,massive cultural and
technological change has occurred in these 40,000 years, human
beings inmodern environments are often mismatched with their evolved
natures, and the frequency andmagnitude of mismatch for a particular
individual is correlated with both physical andpsychological pathology.
The concept of nature- culture reconciliation will offered as
analternative to traditional mismatch theory and applied to forms
of psychopathology involving fearand aversion to strangers.
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Information and Society: Towards a New Academic Discipline.
Steven Bankes
RAND, 1700 Main Street,
P.O. Box 2138
Santa Monica, CA 90407-213R
e mail: bankes@rand.org
Since the 1970s, extensive intellectual ferment has occurred around
the idea that all organizedsystems, including living organisms
as well as societies, depend at their core on how informationis
generated, transmitted, processed. ant utilized. This is leading
to an information-processingview of human organization and society.
This view, if it can be consolidated into a coherent discipline,
would provide the basis that is now missing for reasoning about
direct and indirecteffects of information and information technology.
This field would complement studies of human institutions based
on the flows of capital (economics) or power (political science),
by studying thehuman impacts of information: its generation, storage,
processing, and communication to effect control.Changing technology
and its effects on society has provided ample evidence of the
role ofinformation plays in social behavior. However, identifying
and exploiting the effects ofinformation and information technology
is made difficult by the lack of theoretical frameworks for reasoning
about the role of information in human societies, institutions,
and organizations.Information flows and relationships are considered
in various social science disciplines, but always peripherally.
As the information revolution unfolds, we are gaining perspectives
on the effects ofinformation and information technology that do
not fit well into the standard academic disciplines and research
fields.In order to reason cogently about the effects of information,
new models of institutions,organizations, and societies are needed.
By considering information stocks, flows and relationships as
central, these models would provide a better understanding of
how informationflows interact to structure and support the functioning
of human collectives. Computer modeling
methodologies developed by researchers in Artificial Life can
be readily adapted to the needs ofresearch into information effects
in human societies. The resulting Artificial Societies may provide
a new basis for reasoning about the nature of the human phenomenon.
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Effects of Parental Divorce on Sexual Strategies of Children
Nigel Barber
Birmingham-Southern College
Birmingham, AL 35254
The literature on children of divorce focuses on the emotional,
attitudinal, and sexual problems ofthese young people. Belsky,
Steinberg, and Draper (1991) interpreted these social problems
aspart of an adaptive environmental switching mechanism according
to which low levels of parentalinvestment result in an opportunistic
interpersonal style, particularly in relation to mating.Preliminary
data indicates that the above model applies to male children of
divorce, but notfemales. Results are discussed in terms of an
alternative genetic model according to which divorceis (1) highly
heritable and (2) based on low need for social approval.
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Regressive stabilization in Human Individuals and Societies
John O. Beahrs, M.D. (116A-OPC)
Portland D.V.A. Medical Center,
P.O. Box 1036,
Portland, OR 97207and
Department of Psychiatry,
Oregon Health Sciences University
Regressive dependency is a destabilizing relational process in
which disadvantaged and/ordistressed subordinates accept material
and/or emotional support from dominants, but respondwith increasing
distress, regressive behavior, and acting out against the dependency
that they evermore desperately seek. Many adaptive schemata contribute:
parent-child conflict, thepsychological trauma response, and selective
affiliation. Concurrent with parents' physicaldominance over children
is a deeper level at which this asymmetry is reversed the coercive
effectof infants' helpless distress on caregivers, who are shaped
to depend on offspring's response fortheir own well-being. Conflicting
power asymmetries become destabilizing, as growing offspringlearn
to willfully use passive control toward instrumental ends. Maturation
requires that childrenlose the ensuing dominance struggle in order
to seek new territory and win the "game of life."Helper-client
relationships re-enact these dynamics. When both are traumatized,
attributesconcealed by shared self deception may reverse the desired
outcome. Clients'' intact but hiddencompetencies enable more potent
passive control strategies, and helpers' beneffectance concealsprofound
dependency on others' appreciation, increasing their vulnerability.
When passive control prevails, regressive dependency results.
Enmeshed dyads seek affiliative relief from in-groups whounite
against perceived enemies by legitimizing the passive control.
This leads to a polarizingeffect that extends regressive destabilization
to the greater societal milieu. To avoid collective regression
requires that helpers retain firm active control, hold their clientele
accountable for the consequences of their actions, and encourage
autonomous
individuation.
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Primogeniture, Monogamy, and Reproductive Success in a Stratified
Society
Ted Bergstrom
Economics Dept,
University of Michigan
Ann Arbor, MI 48109
e-mail tedb@umich.edu
This paper constructs and tests a formal model of a stratified
society in which there is primogeniture and where the nobility
practice monogamous marriage with a double standard of sexual
fidelity. The model formalizes ideas presented in a series of
papers by Laura Betzig. Withinthe model, one can determine the
reproductive values of the male and female nobility relative tothat
of commoners. The hypothesis that preferences have evolved to
favor maximization of reproductive value has testable implications
about the size of brides' dowries relative to the valueof their
husbands' estates and about the issue of female succession in
the absence of a male heir.The hypothesis is tested against fragmentary
data from ancient civilizations and quite detailed information
about the British aristocracy in the late medieval and early modern
periods.
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Law Makers as Gene Replicators
Laura Betzig
Evolution & Human Behavior Program
Museum of Zoology/
University of Michigan/
Ann Arb or
Ml/48109-1079/USA
Laura.L.Betzig@um.cc.umich.edu
Why do people make laws? For two possible reasons. One is: To
reproduce. The other is: Tomake sure competitors don't. In the
history of the West, law makers have done both. Secularlaw--of
the sort that Roman emperors or English kings imposed on their
subjects-- consistently punished celibacy. It said, in effect,
"You must make more children." Religious law--of the
sortthat medieval church men imposed on lay men--consistently
punished polygamy. It said, "Youcan't make more children.."
Secular and religious law were, in other words, diametricallyopposed.
Why? Because the first was a kind of between-family competition;
and the second was akind of within-family competition. Kings and
emperors wanted competing families--Englishbarons, or the old
Roman republican aristocracy--to leave too many heirs. That way,
their wealthwould disperse. Church men wanted lay men--the elder
brothers who'd come into their fathers'estates--to leave no heirs
at all. That way, they might succeed to their fathers' estates
themselves.Law-making emperors, church men, and kings all got
richer; and law-abiding senators, lay men,and barons all got poorer.
And men who got rich in the ancient, medieval, or modern West--likemen
who've got rich almost anywhere else--probably had sex with more
women, and probablyfathered more children.
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THE NATURE OF LANGUAGE AND ITS BIOLOGICAL UNDERPINNING
Bernard H. Bichakjian
U. of Nijmegen,
The Netherlands.
E-mail: Bichakjian@let.kun.nlIf
psychology is recovering from a period when the establishment
had imposed a taboo on linkinghuman behavior to its biological
underpinning, linguistics is still feeling the full weight of
a similaryoke. This paper will break the taboo, and, leaving from
the observation that languages are sets ofsounds and strategies,
it will argue instead that these features have been shaped and
continue tobe shaped by the selection pressures that weigh on
their biological underpinning. The role of biology was not to
produce once and for all a machine, frozen in time and universal
in space,which cultures would use in their own idiosyncratic ways
to churn sentences. Biology has neverstopped being active, and
it continues to this day to remodel linguistic features as the
biochemicalprocesses that produce their anatomical correlates
interact with the selection pressures that weighupon them. The
pressures vary, and the responses differ as well -- hence the
diversity of languages-- but everywhere linguistic features have
been driven by the selection pressures that theirbiological underpinning
have had to bear. Only as we recognize this interaction are we
in aposition to understand the shape of linguistic features and,
thereby, the nature of language.
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Child care in a population of Maasai agro-pastoralists.
Adam Biran
Dept of Anthropology,
UCL,
Gower St, London WC1E 6BT, UK
Email: ucsamab@ucl.ac.uk
Observational data on child care from a study of thirty-nine Maasai
infants are presented. Thesedata are used in combination with
records of the biological relationships between infants andpotential
caretakers. Factors affecting the probability of an infant receiving
care and theprobability of a potential carer providing care to
an infant are examined. The results are discussedin the context
of evolutionary theory.
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EVOLUTION OF EGALITARIAN BEHAVIOR
Christopher Boehm Director,
Jane Goodall
Research Center Department of Anthropology,
USC,
LA, CA 90089
The chimpanzee "waa-bark" is explored as a species-specific
signal of defiance used bysubordinates to protest domination (video
examples). Coalition behavior by chimpanzees isexamined as a possible
pre-adaptation for egalitarian behavior among foragers: chimpanzeecoalitions
range from pairs of males seeking dominance to entire communities
hunting, mobbingpredators, or (rarely) manipulating the roles
of alpha-types. Egalitarian society is taken to be theresult of
a whole-community coalition suppressing male status rivalry, and
the politicalintelligence and social dynamics involved with forager
egalitarian behavior are dissected. Suchbehavior involves a coalition
of the entire group that moralistically labels would be alpha-maletypes
as deviants and sanctions them accordingly. It is suggested that
chimpanzees are not likelyto effectively neutralize alpha-male
dominance as humans do, and that the acquisition of moralitywas
more important to human leveling of hierarchical tendencies than
was language, per se.
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Evolution, Ethics & Artificial Life.
John Bragin
UCLA Center for the Study of Evolution and the Origin of Life
Los Angeles, California 90095-1567
e-mail: johnb@ess.ucla.edu
Many researchers in Artificial Life claim to be not only modeling
or simulating life, but to besynthesizing it as well. What is
or might be the moral status of such entities produced in test-tubes,
computers, and robot labs? Debate on this question is an extension
of two other questions:"What is life?" and "What
is the basis for or justification of ethical precepts?" When
organicspecies--including humans--were considered to be the products
of divine special creation, theanswers to these two questions
were dear. But Darwinian evolutionary theory has replacedNatural
Theology and most biologists and philosophers no longer believe
that religiousor non-religious Vitalist concepts do any work in
science or ethics. Since Darwin's time somephilosophers and biologists
doing philosophy have sought evolutionary characterizations of
theorigin, nature, justification, and applicability of human ethical
capacities and precepts. Others haveargued against any inference
from "what is" to "what ought to be." The
advent of what somehumans call living entities--even when produced
by humans themselves--appears only toexacerbate ethical problems.
What, for example, would it mean for a human to cause pain to
an Artificial Life entity? This talk will review various ideas
on the question "What is Life?" and thendiscuss whether
deontological, utilitarian, or other views of morality can help
with the problem ofethics and Artificial Life.
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Paternal Certainty and Female Dominance: Should Males Prefer Submissive
Females?
Stephanie L. Brown & Douglas T. Kenrick
Arizona State University,
Tempe, AZ 85287
Email: asslb@asuvm.inre.asu.edu
Previous research on male mate selection criteria finds no relationship
between female dominanceand attractiveness. This is surprising,
because paternal certainty depends on sexual control. Thepresent
study re-tested the hypothesis that males should be attracted
to submissive females bymanipulating dominance as a power differential
rather than a personality trait. Two hundred maleand female undergraduates
from Arizona State University rated either a male or female target
whowas described to be either the subjects' supervisor, co-worker,
or assistant. Contrary to previouswork on female dominance, the
gender x dominance interaction indicated that males were mostattracted
to the female target when she was in the submissive role. Our
analyses include tests ofalternative explanations in an attempt
to converge on the possible role of paternal certainty inproducing
this effect
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Evaluation of an Evolutionary Model of Self-Preservation
R. Michael Brown, Eric Dahlen, Cliff Mills, Jennifer Ricks, Arturo
Biblarz
Department of Psychology,
Pacific Lutheran University
BROWNRM@PLU.EDU
According to deCatanzaro's (1991) mathematical model of self-preservation,
staying alive actuallymay reduce inclusive fitness in an individual
who is low in reproductive potential and, at the sametime, poses
such a burden to close kin that it costs them opportunities for
reproduction. We tested
predictions generated from this model using 175 university students
as subjects and variablesconstructed from a questionnaire. The
criterion variables were separate measures of hopelessness,depression,
suicidal ideation, and suicidal behavior. The predictor variables
were separatemeasures of reproductive potential of the individual,
reproductive potential of the individual's kin,relationships with
parents, relationships with friends, and locus of control. Multiple
regression analyses showed that burdensomeness to kin was the
best predictor of both hopelessness anddepression, as predicted
by deCatanzaro's model. Moreover, discriminant analysis showed
thatreproductive value of kin significantly differentiated suicide
attempters from nonattempters.
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Altruism Facilitates the Formation of Social Support Networks
William Michael Brown and Boris Palameta.
Psychology Department,
St. Thomas University
Fredericton, N.B., Canada,
E3B 5G3e-mail: PALAMETA@STtHOMASU.CA
Altruism may be stable if based on Tit-for-Tat strategies. However,
detection of cheating is notalways possible. People recognized
to possess an altruistic predisposition may be preferredpartners
in cooperative ventures, because they are less likely to cheat.
If this is true, altruism mayfacilitate the formation of social
support networks. A study was conducted over a 4-month periodto
investigate whether altruism facilitated the formation of social
support networks in 118 femalefirst year university students.
Scores were obtained from self-report questionnaires involvingmeasures
of socially desirable responding, altruism, social support, and
relationship quality at thebeginning of the school year and then
again toward the end. The result of stepwise multipleregression
analysis indicated that the variables most strongly related to
social support werefriendship quality, overall relationship quality
and altruism. Comparisons of the cross-laggedpartial correlations
revealed that altruism preceded social support, suggesting a causal
linkbetween the two variables. This implies the discovery of a
mechanism that allows altruismbetween unrelated individuals to
be an evolutionarily stable strategy.
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EVOLUTION, DEVELOPMENT, & CHAOS: The role of nonlinear epigenetic
processes.
Robert L. Burgess,
Penn State University,
110 Henderson Building South,University Park, PA
(RLB8@psuvm.psu.edu)
Peter C.M. Molenaar,
Universiteit van Amsterdam
Increasingly, evolutionists recognize the value of examining linkages
between thosespecies-typical traits that are shared by all normal
humans as well as those features of the geneticsystem that vary
between individuals. In this paper, we address some of the key
issues, focusingparticularly on how the powerful class of nonlinear
reaction-diffusion models used bymathematical biologists can explain
emergent organismic properties and how the methods ofdevelopmental
behavior genetics enable the decomposition of phenotypical longitudinal
trajectories into underlying genetic, environmental, AND epigenetic
processes, with the latter constituting an important "third
source" of developmental differences.
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.
Human Prestige Criteria
David M. Buss
Department of Psychology
University of Michigan
Ann Arbor, Michigan 48109-1109
Prestige, status and reputation influence a host of survival and
reproductive problems, includingaccess to mates, food, territory,
desirable alliances, preferred coalitions, and favorable treatmentfrom
others. Relatively little is known, however, about the evolutionary
psychology of prestige,status, and reputation, and in particular,
about what causes prestige to increase or decrease. Thi spaper
offers a theory of "prestige criteria," defined as the
content dimensions along which prestigecan be increased or decreased.
New data from Ethiopia, Germany, Poland, China, Guam, USA,and
Hungary (Transylvanian Gypsies) are presented to test facets of
the theory. Many prestigecriteria appear to be universally sex-
linked. Having sex with three partners in the course of oneweekend,
for example, damages a woman's prestige more than a man's prestige
in all cultures.Discussion elaborates an evolutionary psychological
theory of human prestige, status, andreputation
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Context Effects on Willingness to Engage in Extrapair Copulations
Bram P. Buunk & Regine van en Eijnden
Department of Psychology
University of Groningen,
Grote Kruisstraat 2/l9712 TS Groningen,
The Netherlands
Mating strategies are to some extent frequency dependent. Evolved
gender differences in sexualitysuggest that among men the perceived
prevalence of extrapair copulations in the populationswould be
more strongly related to one's own willingness to engage in extrapair
copulations than among women. Study 1 provided correlational evidence
for this prediction. Study 2 showed thatamong men, but not among
women, exposure to a message that 47% of the 0population hadengaged
in extrapair copulations led to a higher inclination to become
involved in EPC's oneself than exposure to a massage that only
3.8% had done so. This effect was especially found amon gmen who
were before already open to short-term mating.
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Modernization's Effects on the Mortality
Costs of Reproduction
Arlen D. Carey
Department of Sociology and Anthropology
University of Central Florida
Orlando, FL 32816-1360;
e-mail: carey@pegasus.cc.ucf.edu
The sex mortality differentials of the 1940-1980 Mexican American
population of Bexar County,Texas, are analyzed using advanced
life table techniques and a quality data set that captures thepopulation's
mortality transition. In 1940, young adult females were at a survival
disadvantage ofmore than 1.5 years when compared to their male
counterparts, due largely to high rates ofmaternal-related mortality.
By 1980, female deaths from such causes were nearly eliminated,
whilemales' reproductive mortality costs had increased considerably.
These changes were responsiblefor much of the almost 4 year increase
in females' overall longevity advantage.
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An Evolutionary Theory of Literary Figuration
Joseph Carroll
English Department,
Univ. of Missouri--St. Louis
St. Louis, MO 63132
(314) 432-5583
sjccarr at umslvma.umsl.eduI
put forward two hypotheses on literature, one about cause and
the other about function. The causal hypothesis is that the structure
of meaning in all literary texts is the direct result of authoridentity,
which is itself produced by the interaction of innate characteristics
and environmentalinfluences, including cultural influences. The
second hypothesis is that literary texts are particularforms of
cognitive maps; that is, like other forms of cognitive activity,
their primary function is tolocate the organism within its environment.
One main purpose of literature is to let us know whatit feels
like to experience given environments from given points of view.
I argue thatrepresentations of characters, settings, or actions
constitute a single, continuous scale with realismat one end of
the scale and symbolism at the other, and I delineate a specific
system of categories for the analysis of meaning in all literary
figurations. To illustrate this system, I compare thethematic
structure of three world views: Christianity, scientific materialism,
and postmodernism.
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Estimating Variance in RS by Sex Among Tribesmen Using Field Census
Data
Napoleon A. Chagnon
Anthropology Department
UCSB
Collecting genealogical and completed fertility data on males
and females in tribal populations canbe a time-consuming and costly
procedure, especially among peoples like the Yanomamo Indiansof
Venezuela who are often reluctant to provide reliable information
about deceased kin andancestors. Recent field studies in remote,
essentially uncontacted Yanomamo villages resulted inrather complete
and reliable census data of living residents in these villages,
but to calculatevariance in RS among them would take years and
many return field trips. This paper exploresways of estimating
variance in male and female RS by simply counting the numbers
of parents ofboth sexes that were involved in reproducing the
living residents and then comparing these resultsto those obtained
in other villages for whose residents the PI has more reliable
measures of completed fertility.
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Honing Ockham's Razor: Fundamentals of Visual Art
Kathryn Coe
Arizona State University
Tempe, Arizona 85287-2702
E-Mail: ICMKC@ASUVM.INRE.ASU.EDU
The focus of this paper is on an elusive concept, namely the visual
arts, which Diamond (1992)referred to as "perhaps the noblest
human invention": (p. 139) and which a number of scholarshave
argued is crucial to the happiness and well-being of individuals
and to cooperation ingroups. Although it may be true that visual
art is important, as it is found in all societies, it isequally
true that not all societies are equally enamored with art. While
the modem art marketmay encourage artists and reward their creativity,
the Amish, ancient Chinese, new republics(including that of Plato),
dictatorships, Orthodox Jews, and Protestant and Catholic churches,among
many others, have greatly restricted the range of acceptable art
and the freedom of theartist. The primary aim of this paper is
to attempt to explain this dichotomy by using modernDarwinian
theory and its methodologies. It is proposed that whatever else
visual art may be, itinvolves the use of color, form, and pattern
to attract attention to an object. Humans have beendesigned to
respond to color and pattern; artists exploit this interest in
order to influence socialbehavior. By attracting attention to
an object, art attracts attention to any messages associatedwith
that object, thus also making those messages more attractive.
Plato claimed that art attractedattention to themes of selfishness
(it "fed and watered the passions')(1942, p. 233) andthus
influenced selfish behavior in the observer. Tolstoy, on the other
hand, argued that art wasused to attract attention to messages
about selflessness or morality - "the highest good at whicha
society aims...humility, purity, compassion, love" (1979,
p. 76). Art thus influenced brotherlybehavior. In this paper it
is proposed that Plato and Tolstoy both may be correct, in that
artinfluences behavior. Art may have come to be revered by some
and reviled by others preciselybecause of its effects on social
behavior.
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USING LITERARY MATERIAL AS DATA IN HUMAN BEHAVIORAL STUDIES:ESTABLISHING
A RIGHT RELATIONSHIP BETWEEN LITERARY RESEARCH AND EVOLUTIONARY
PSYCHOLOGY
John Constable
Faculty of Integrated Human Studies,
Kyoto University,
Sakyo-ku, 606-01, Japan.
Fax: 075 753 6647
e-mail: john@ic.h.kyoto-u.ac.jp
The position of literary studies in the university is now openly
questioned by many, and as aconsequence researchers in threatened
areas are energetically seeking to discredit their opponents,or
otherwise to justify their work. Even those who are genuinely
friendly in seeking closer tieswith scientific disciplines also
pose a threat in that these scholars may insist on retaining criticaland
evaluative imperatives that conceive of literary studies as an
"end-user", and thus ensure thatno significant contribution
to neighboring disciplines is possible. In this paper I will attempt,
first,to characterize the problem, and then to show how students
of literature who were forced toavoid this error would function.
I shall conclude with a thumbnail sketch of a particular study,
thestudy of satirical literature, which fulfills my conditions
for being in a right relationship toevolutionary psychology
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The Inexhaustible Interest of Verdi's Rigoletto
Brett Cooke Department of Modern and Classical Languages
Texas A&M UniversityCollege Station,
TX 77843-4238
(409) 693-3704; FAX (409) 845-6421;
Ibc3432@tam2000.tamu.edu
Evolutionary psychology reveals the latent substructure generating
the virtually inexhaustiblenarrative force of Verdi's much-performed
Rigoletto. The plot derives from the geneticdistinctions supposedly
evident between the handsome but profligate Duke of Mantua and
thehunchbacked Rigoletto. Visible birth defects traditionally
were attributed to supernatural powers;evolutionary tenets predict
they trigger aversive behavior, often whether or not they are
genetic.As a result, defects attract interest, leading to further
consequences. Notions of the "crookedman" extend to
his character. Such is the sadly misshapen Rigoletto, a perhaps
overly devotedfather, widower and yet wicked-tongued jester. Although
he has an unusually beautiful daughter,his "curse" does
much to account for the otherwise irrational events in this strangely
amoralopera: Rigoletto's lot in life, his claustration, then pandering,
of Gilda, and her decision tosacrifice herself for the Duke, who
deceived her and lives on to seduce other women.
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Episodic Memory, Theory of Mind, and their Breakdown
Led a Cosmides* & John Tooby Center for Evolutionary Psychology,
University of California, Santa Barbara,
CA 93106
Episodic memory is believed to a distinct and neurally localizable
form of memory whoseindependence can be established by many methods,
including dissociation studies: Individuals withbrain damage sometimes
lose their ability to remember past episodes, or to store new
ones, whilethe rest of their memory remains intact and relatively
unaffected. Among other defining features,episodic memory involves
the storage not just of information, but of the circumstances
ofacquisition of that information by the individual -- source-
tagging. In parallel, studies of cognitivedevelopment indicate
that our species-typical cognitive architecture contains a specialized
subsystem, the Theory of Mind Module (ToMM), that is designed
to interpret and represent thebehavior of others in terms of inferred,
invisible folk psychological entities, such as beliefs anddesires.
Components of this specialized system are believed to be restricted
to humans andperhaps their close relatives, and to underwrite
sophisticated abilities to cooperate with,communicate with, deceive,
and successfully predict the behavior of others. The reality of
this system is also supported by dissociation studies: people
with autism are believed to suffer from aselective impairment
of their ToMM. In certain important respects, the format of the"M-representations"
built by the ToMM parallels the format of episodic memory representations.This
suggests a close relationship or mutual dependence between the
two systems. This wouldimply, for example, that episodic memory
would be impaired in individuals with autism, and thatchildren
would have no episodic memory prior to the emergence of their
ToMM. Other disorders,such as schizophrenia, appear to involve
breakdowns in source-tagging, leading (as Frith & Frithhave
suggested) to a possible explanation for the cluster of disabilities
individuals withschizophrenia regularly manifest, and to the prediction
that their episodic memory might also beimpaired.
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The Evolutionary Significance of True Pathologies, Pseudopthologies,
and PseudonormalConditions
Charles Crawford,
Department of Psychology,
Simon Fraser University,
Burnaby,B.C., Canada, V5A lS6;
E-mail Charles_Crawford@sfu.caI
distinguish between the innate adaptation, unchanged in recent
evolutionary time, and theoperational adaptation, which may differ
in ancestral and current environments because ancestraland current
developmental and immediate environments may differ. l then distinguish
betweendirect stress to physiology and anatomy in which decision
processes are instantiated, and indirectstress, which is the result
of failures of information processing due to faulty learning,
inadequateor conflicting information. These distinctions are used
to define an evolutionary classification ofpathologies. I then
use these concepts to discuss the nature and significance of true
pathologies(pathological in all environments), pseudopathologies
(adaptive in ancestral, maladaptive incurrent environment), and
pseudonormal behaviors (acceptable now, but maladaptive in ancestralenvironment).
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Parents' Knowledge of their Children's Beliefs & and Attitudes:
An Indirect Assay of Parental Solicitude?
Martin Daly, Cheryl McConnell & Tammy Glugosh
Department of Psychology
McMaster University
Hamilton, Ontario L8S 4Kl
email: Daly@McMaster.CA
In two studies, undergraduates filled out questionnaires containing
various attitude and beliefitems, and their parents then provided
both their own responses to the same items and their bestguesses
as to how their children had responded. As predicted, stepfathers
were significantly lessaccurate than genetic fathers, and maternal
accuracy increased as a function of the mother's agewhen her child
was born. Overall, mothers and fathers did not differ in accuracy,
nor wereparental guesses differentially accurate for daughters
vs sons. However, mothers were mostaccurate in guessing the views
of first-born sons, while fathers tended to be more accurate about
daughters' views. These results suggest that parents' ability
to guess their children's views mayprovide a useful index of parental
interest and/or of parent-child closeness.
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Born Too Late?: Parental investment and birth order in modern
Canada
Jennifer Davis-Walton
McMaster University
Hamilton, Ontario
davisjn@mcmaster.ca
Analysis of a 1990 Statistics Canada survey suggests that birth
order does, in fact, modulate theamount of parental investment
modern Canadians receive. Using the age at which children lefthome
and the highest level of education attained as measures of the
amount of investmentreceived, it was discovered that oldest children
are relatively unaffected by the number of youngersiblings they
have, while youngest children suffer from decreases on both measures
the more oldersiblings they have. Additional analyses suggest
that similar patterns may also appear in measuresof adult life
outcomes.
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Grandparental Investment and the Uncertainty of Kinship
W. Todd DeKay
University of Michigan,
Department of Psychology,
525 East University, Ann Arbor, MI 48109
1109dekay@um.cc.umich.edu
Previous research has focused exclusively on the uncertain nature
of paternity. However, otherkin members often face a problem similar
to paternal uncertainty, a problem called "relationaluncertainty
(RU)." This concept represents the number of times in the
line of decent between twokin members that the genetic relationship
between them could be severed by cuckoldry. Forfathers, RU=l.
For mothers, RU=0. For grandparents, RU can range from 0 to 2.
Two studiesexamined the potential role of RU in grandparental
investment decisions. Results indicate that RUis predictive of
grandparental investment patterns and of the emotional closeness
betweengrandparents and grandchildren. Discussion focuses on the
implications of these findings forunderstanding cooperation within
families and for a broader model of cooperation.
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SOUTH TURKANA HOMICIDE: A PROXIMATE VIEW
Rada and Neville Dyson-Hudson
Binghamton University
Some 'low-conflict societies' with affectionate socialization
and aversion to inter-personalconfrontation (e.g. Inuit, !Kung
Bushmen, Gebusi of lowland New Guinea) are reported as havinghigh
rates of violent death. In contrast, Turkana pastoralists (East
Africa) are taught to fight aschildren; and most men reported
having participated in inter- personal fights intended to causeinjury,
having engaged in recreational within-group fighting mimicking
warfare, and having takenpart in raids on the neighboring Pokot.
Yet demographic data indicate that within- grouphomicide rates
among the 'violent' Turkana are lower than those reported for
the 'low-conflict'societies. Apparently Turkana rules which require
bystander intervention, direct expression ofaffect, and adjudication
by elders, are effective in preventing within-group aggression
and violencefrom escalating into lethal fights. The discordance
between socialization for violence and homiciderates shows the
necessity of distinguishing between high incidence and/or valuation
of aggressivebehavior, and the rate at which people actually kill
one another. It also indicates that effectiveconflict management
may be more important than learning of non-aggression for prevention
lethalviolence.
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OLD GENES, NEW WAYS AND HEALTH: REPRODUCTIONS.
Boyd Eaton, M.D.
Departments of Radiology & Anthropology,
Emory University
2887 Howell Mill Rd,
NW; Atlanta, Georgia 30327
Phone (404) 350-5567, Fax (404) 352-2529
Late Paleolithic reproductive experience differed from that in
the present: later menarche andearlier first birth, more pregnancies
and nursing, fewer ovulations and earlier menopause. Thechange
from Paleolithic to modern experience increases cell turnover
rates in reproductive tissuesthereby heightening susceptibility
to carcinogenic mutations. Epidemiological modeling suggestswomen
today have 100 times the breast cancer risk of Stone Agers. Demographic
and socialconsiderations exclude reinstitution of Paleolithic
reproductive experience, but interventional endocrinology might
recreate ancestral physiology. Those opposed to such measures
mustrecognize that breast cancer mortality has not improved since
1930.
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OLD GENES, NEW WAYS AND HEALTH: NUTRITIONS.
Boyd Eaton, M.D.
Departments of Radiology & Anthropology,
Emory University
2887 Howell Mill Rd,
NW; Atlanta, Georgia 30327
Phone (404) 350-5567, Fax (404) 352-2529
Human diets during the Late Paleolithic arguably represent the
nutritional spectrum for which weremain adapted. Then fruits,
vegetables, nuts and game provided nearly all food energy; nowcereal
grains, sugars, dairy products, oils, alcohol and fatty meat constitute
the bulk of what weeat. These departures from ancestral human
nutrition have profound consequences for health:heart attack,
stroke, cancer, hypertension and diabetes are all nutritionally
related. In each casedisease development is promoted by dietary
changes which have occurred since agriculture and,for each, preventive
recommendations reprise Paleolithic nutrition.
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Adaptations from Psychiatry and Psychoanalysis
Anne Eisen, M.D.
202 East Washington 400B
Ann Arbor, Ml 48104
Complete evolutionary descriptions of many human behaviors are
enhanced by the clinical dataand discoveries of psychiatry and
psychoanalysis, while these fields benefit from evolutionarydiscoveries
and theory. I will consider discoveries made in parallel by both
clinicians andevolutionists such as the existence of involuntary
(unconscious) adaptive mechanisms and theubiquity of conflict.
Specifically, mechanisms of hierarchy negotiation and conflict
managementare explored from the perspectives of different fields
to illustrate how each complements andenhances the understanding
of the other.
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The Phylogenetic Development of Shame and Pride
Daniel M.T. Fessler
Department of Anthropology,
University of California, San Diego
Both ethological and psychological data indicate that shame and
pride are panhuman experiences.These emotions are important in
many systems of social control, most notably those found insmall
groups. This suggests that shame and pride have played an integral
part in the evolution ofhominid social behavior. Display patterns
indicate that both emotions have their roots in motivesand signals
associated with dominance relation- ships, yet, from the cognitive
perspective, issuesof rivalry are often subordinate to a concern
with the relationship between the individual and thegroup. It
thus appears that at some point simple rank-related emotions changed
into newemotions which promoted conformity. Shame and pride are
reactions to the opinions of an Other,and hence the ability to
experience them is dependent on the capacity to hold a model of
mind.This capacity also allows for increases in cooperative activity.
Because participation incooperative efforts has tangible rewards,
and inclusion in such activities is contingent on apositive evaluation
by others, the possibility of cooperative action results in selective
pressure fora sensitivity to others' opinions of one. Of equal
importance, cooperative activities entail a sharedplan and hence
a shared standard for behavior. Individuals seeking inclusion
must be especiallysensitive to such a shared standard. The benefits
of participation in cooperative activities thuscreated selective
pressure for an affect-laden attention to norms. This, in turn,
may have providedthe foundation for the elaboration of culture.
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HEURISTICS, EVOLUTION, AND RATIONALITY
James H. Fetzer
Department of Philosophy
University of Minnesota
Duluth, MN 55812
Email: jfetzer@d.umn.edu
Actions are widely-assumed to be "rational" when they
maximize subjective utilities determined by personal probabilities
and utilities. This does not in turn require that these personal
probabilitiesare justified by any evidence. When we base our personal
probabilities nol merely on subjectiveopinions but upon objective
probabilities in the form of relative frequencies or nomic probabilities,then
any actions we base upon them are supported by rational beliefs.
By acquiring informationabout relative frequencies and knowledge
of nomic probabilities and insisting that our personalprobabilities
be based upon it, our rationality can go beyond our genetic heritage
and our personalhistories. Heuristics thus enable us to transcend
the limitations of our genes.
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Are There Really Separate Reasoning Mecbanisms for Social Contracts
and Precautions?
Larry Fiddick*, Leda Cosmides, and John Tooby
Center for Evolutionary Psychology,
University of California, Santa Barbara,
CA 93106
Unlike many anatomical adaptations, which can be seen with the
naked eye, computationaladaptations of the human mind must--at
present--be studied by testing which alternative theoriesof their
design accurately predict new experimental observations and economically
account forexisting ones. Although there is now a large body of
experimental evidence best explained bypositing the existence
of several distinct, functionally specialized reasoning modules
(e.g., forsocial exchange, precaution, threat), questions persist
about the reality of these hypothesized modules, patticularly
given that most psychologists prefer the hypothesis that the mind
consists ofa small number of content-independent procedures. The
phenomenon of priming--in which solvingone problem enhances performance
on subsequent ones--provides an independent approach forestablishing
the realiq and boundaries of hypothesized modules. The consensus
view of priming isthat the prior activation of a mental mechanism
physiologically facilitates the immediatelysubsequent activation
of the same neural mechanism. By seeing what primes what--by seeing
whatproblems are routed to and operated on by the same mechanism--one
can identify the mind's ownnative categories of "similar
problems". Cognitive psychologists have found it extremely
difficultto discover any priming for rule-based reasoning tasks
- a finding that called into question whetherthere was any rule-based
structure to the mind. We have found, however, that when reasoning
tasks are categorized according to adaptive domain--precautions
and social contracts - and tested in sequential pairs, priming
robustly occurs within the adaptively defined domains, but not
across adaptive domains. This implies that the computational architecture
of the mind itself distinguishes between these types of rules
on the basis of the adaptive domain they belong to, applying differentprocedures
to problems in different adaptive domains, and the same procedure
to problems in thesame adaptive domain. These results support
the view that the hypothesized domain-specificmodules actually
exist and have the design attributed to them.
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HUMAN DIVORCE PATTERNS: How neural mechanisms in the brain influence
divorce andinteract with American divorce law.
Dr. Helen Fisher
Rutgers UniversityOffice:
65 East 80th Street,
NYC NY 10021
Data on divorce taken for all available years between 1947 and
1989 from the DemographicYearbooks of the United Nations on 62
peoples exhibit several patterns unrelated to divorce rate:Among
these, divorce risk peaks in age categories 20-24 and 25-29 and
remarriage counts peak inage categories 25-29 and 30-34. It is
hypothesized that this pattern of cyclic pairbonding duringreproductive
years is governed by neurophysiologic mechanisms in the Limbic
System of theBrain that generate the emotions for attachment and
detachment, and that these neural systemsevolved by one my BP
to predispose ancestral hominids to bear and rear young (through
theduration of infancy) with serial mates. This paper examines
these neurochemical mechanisms andhow they interact with contemporary
cultural forces and American, divorce law.
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A re-examination of Singh's waist-hip ratio figures: A check of
validity and generalizability.
Ann Flood and Charles B. Crawford
Department of Psychology,
Simon Fraser University
Burnaby, British Columbia V5A lS6, Canada
e-mail charles_crawford@SFU.CA
This paper examines the validity and generalizability of Singh's
(1993) waist - hip ratio (WHR)figures. The figures consist of
12 female line drawings varying in weight and WHR. Singh foundthat
figures with low WHRs were judged more attractive and reproductively
capable than figureswith higher WHRs. In this study, we hypothesized
that (1)judgments of figures in a group woulddiffer from judgments
of figures in isolation, and (V Singh's figures, posed as though
in a beautypageant, would be rated higher on courtship variables
than figures in a more natural pose. Results supported both these
hypotheses. In addition, we found that the figure's weight influenced
ratings more than WHR.
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A NAME="How Could Something">#
How Could Something Evolve? Companng Memetic and Geneldc Evolutdon.
Liane M. Gabora
UCLA Department of Zoology
Los Angeles, California 90095
e-mail: liane@cs.ucla.edu
The mechanisms and patterns in evolution emerge from the variation
and selective replication ofpatterns of information. Despite the
differences in the mechanisms underlying biological andcultural
evolution, human experiments and computer simulations reveal deep
processualsimilarities, such as drift, epistasis, and a trade-off
between short-term optimization and long-termflexibility. Kaufmann
has proposed that life is an expected emergent autocatalytk phenomenonwhich
arises when polymers begin to mutually catalyze their collective
reproduction. Unlike DNA,memes are not inherently self-replicating,
but spread when human minds, their hosts, teach andimitate one
another. Thus whereas the origin of life requires the appearance
of only one initialpattern-evolving system, cultural evolution
requires that many pattern- evolving systems,conscious minds,
come into existence independently. The cultural analog to the
origin of lifehappens every time an infant becomes capable of
a sustained stream of thought through the self-organization of
a set of memories connected by associative links as described
in Kanerva's sparse distributed model of memory. This suggests
that autocatalysis plays a vital role in the bootstrapping of
both biological and cultural evolutionary process.The human mind
is a meme host operating at thc edge of chaos. Our thoughts are
the objects of aself-propelled evolutionary process; we do nothing
to give birth to "our" memes other thanprovide a fertile
ground for them to grow and multiply. We preferentially store
and implementmemes that we associate with our concept of self,
thus we are susceptible to the illusion that ourmemes are an integral
part of us. Attractors in the memetic fitness landscape are defined
by ourcurrent array of needs. lhis landscapc is dynamic and fractal;
the invention of a meme to satisfyone need can spawn a set of
entirety new needs, which in turn open up new stream-of-thoughttrajectories.
The inductivity of our memes shows the inverse pown law relationship
characteristicof systems at thc cdge of chaos. Aided by the positive
feedback effects of memetic altruism,humans setf-organize into
groups with rehted interests fostering the evolution of sets ofmutually-supportive
memff much as speciation fosters the evolution of sets of mutually-supportive
genff.
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Human Sexual Selection, Developmental Stability, and Indicator
Mechanisms
Steven W. Gangestad and Randy Thornhill
Department of Psychology and Departrnent of Biology
University of New Mexico,
Albuquerque, NM 87131
e-mail: sgangest@unrn.edu and thorn@unm.edu
Previous research has shown that men's number of sex partners
is negatively predicted byfluctuating asymmetry (FA, e.g., differences
in size of the two ankles, wrists, ears), a measure ofdevelopmental
instability. In this research, we explored potential mediators
of this relation. On203 romantically-involved couples, we obtained:
self- and partner-reports of men's physicality(muscularity, robustness,
vigor), social dominance, and resource potential; self-reports
of theirbody mass, narcissism, and heterosexual assertiveness;
ratings of facial attractiveness; sexualhistory and FA. LISREL
analyses replicated the relation between FA and number of partners.
FAalso predicted body mass, physicality, and social dominance
-- variables that could mediate about70% of the relation between
FA and sex partners. Related analyses revealed that, although
moresymmetrical men give less time and attention to their partners,
they are judged to provide betterphysical protection. Results
are discussed in light of sexual selection models.
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Basic Plans and the Biology of Leadership
Gardner, Russell & Joiner, Thomas
Department of Psychiatry and Behavioral Sciences
University of Texas Medical Branch
Room 4.4S0
Graves Building, D28,
Galveston, Texas, 77555-0428
Basic plan theory uses the tinkering metaphor (natural selection
modifies molecules in newphenotypic adaptations). EEA mismatch
with the present is a fruitful heuristic but nearly all thegenomic
determinants of the human body antedated the hunter-gatherer human.
We propose thata basic plan for human leadership stems from dominance
and other alpha states of non-humanvertebrates. Lines of investigation
include: (l) comparing manic behaviors to those of humanleaders,
(2) noting effects of serotonergic drugs that enhance a nonviolent
"take charge"mentality, (3) comparing features of leadership
to behaviors of Asperger syndrome patients.Adaptive components
of mania include heightened energy, appetite, planning, enthusiasm,controlling
behaviors, and ability to function without sleep. Increased self-esteem
fromserotonergic drugs may fundamentally be a leadership biology
generally without impulsiveviolence (with which low serotonin
and frustration-aggression correlate). Expansion of frontallobes
in the human involves restraint, planning, attention and other
requirements for low key,socially involved yet enthusiastic and
productive leadership functions. We see its opposite inAsperger's
syndrome in which patients have a poor sense of story line, lack
social nuance andsuffer frontal deficits. Examination of psychopathology
and results of drug actions may illuminate the sociophysiology
of normal communications.
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Computational Human Evolution: From Artificial Life to Artificial
Human Evolution.
Computational Evolution has become an established philosophy of
science, body of theory, andmethod of research as evidenced by
a growing number of international multidisciplinaryconferences
including: Artificial Life: the International Workshop on the
Synthesis andSimulation of Living Systems, From Animals to Animates:
the International Workshop on theSimulation of Adaptive Behavior,
the European Conference on Artificial Life: Towards aPractice
of Autonomous Systems, Evolutionary Programming, the International
Conference on Multi Agent Systems, Genetic Programming, and Simulating
Societies. Applications have beenwritten for domestic and foreign
policy, for military gaming, for industrial and academic research,and
for entertainment. In brief, these approaches embrace the aphorisms
of: emergence, "from simple rules to complex behaviors;"
multiple agency, "the interaction of individuals as the determinants
of the behaviors of populations;" and natural selection,
"evolution throughvariation, selection, and amplification."Whether
these investigations are done on desktop or high performance computers,
it is time tobegin to formulate problems of human cultural, societal,
behavioral ant physiological evolution interms which are commensurate
with the computational evolutionary paradigm. And it is time tomodify
that computational evolutionary paradigm in ways which will produce
meaningful answersto human evolutionary theories. At present,
success in these two complementary endeavors seemslimited only
by proper problem conceptualization, massively parallel programming
skills, andadequate computer power. This session will explore
the potential of merging these two fields by reviewing some current
research which is suggestive of potential developments in our
own discipline.
Special Video Presentation (preceeding session):Karl Sims: Evolving
Virtual Creatures. (Presented by proxy by Nicholas Gessler.)Speakers:Nicholas
Gessler.
Artificial Culture Experiments in Synthetic Anthropology.Liane
M. Gabora: How Could Something Evolve? Comparing Memetic and Genetic
Evolution.
Robert Reynolds: Introducing Cultural Algorithms.Steven Bankes:
Information and Society: Towards a New Academic Discipline
John Bragin: Evolution, Ethics & Artificial Life.Equipment
Requirements:Board.Carousel projector.Overhead projector.VH5 player
and (monitor or proiector).
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Artificial Culture: Experiments in Synthetic Anthropology.
Nicholas Gessle
rUCLA - Anthropology,
c/o 11152 Lucerne Avenue
Culver City, CA 90230-4244
e-mail: gessler@anthro.sscnet.ucla.edu
A fresh scientific paradigm, inspired by the sciences of complexity,
is emerging which differs sogreatly from "mechanistic"
science that it has been touted as of philosophy of science in
itself. Inbrief, it is the practice of artificial life which uses
computational (as well as molecular androbotic) models incorporating
at least three fundamental processes: Evolution through naturalselection.
Emergence from local low-level rules to global highlevel patterns
of behavior.Multiple-agency explaining group behavior from the
interaction of individuals. These representations are so compelling
that it is difficult not to describe them in any other way thanwith
terms normally reserved for living systems. Not surprisingly then,
the strong argument hasbeen advanced that these simulations are
in fact alive. The most consequential research programfor science
is the exploration of the congruence of such artificial systems
with their naturalsystems referents. This research specifically
addresses the issue with a superset of these systems:specifically
artificial life scaled up to artificial culture. It seeks to generate
predictively usefulartificial cultural analogs of natural cultures.
After some five years of international conferences on artificial
life, there is reason to expect abright future for computational
approaches towards artificial cultures. The culture in an artificialculture
comprises not only the cognitive processes of individuals (what
they think), but includestheir behaviors (what they do), and the
artifacts or products of their labors (what they make) aswell.
Artificial culture comprises a population of individual agents,
each with its own sensors,cognizers, and actuators interacting
with other agents, with products of their own manufacture,and
with an external world containing objects and limited and situated
resources. All inanimate objects are given a materiality constrained
by a physics, and animate objects are furtherconstrained by a
physiology. This purely computational strategy, along with allied
research incollective robotics, may help to clarify the role of
the individual in society, the dynamics ofcooperation and competition,
and the operation of culture seen as a complex adaptive system.
Itmay also help clarify the positions of the various schools of
anthropological thought.
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Law in a Modular Mind
Oliver R. Goodenough
Vermont Law School
South Royalton, VT 05068
ogoodeno@vermontlaw.edu
There is considerable evidence that the human brain works not
as some kind of unitary processorbut rather as a series of interlocking
and interconnected cognitive "modules." One relatively
easyway to differentiate between such modules is whether they
employ language and language basedrules in the course of processing
information and coming to decisions about action. Inlanguage-using
behavior, this distinction separates the untutored native speaker
from thegrammarian. In the law, it makes transparent the classic
distinctions between positive and naturallaw. The modular approach
also helps explain a number of other perennially troubling questions,including
the workings of the "reasonable person" test of proximate
cause in tort law.
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Intergenerational Female Competition: Older Women's Attempts to
Manipulate the Reproductive Interests of Younger Women
April Gorry
Department of Anthropology,
University of California, Santa Barbara
6500apri@ucsbuxa.ucsb.edu
Competition between women represents an often misunderstood form
of human interaction. In the absence of a functional approach
to human competition, researchers have tended to rely on anintuitive
understanding of the phenomena--centering their analyses on overt,
conscious forms ofinteraction. Research into the use of aggressive
acts and conflict resolution tactics suggest agreater reliance
by women on indirect, covert forms of social manipulation, implying
that much ofcompetition research has an androcentric bias. In
this paper I present a series of acts of socialmanipulation by
older women, drawn from a cross-cultural body of literature, that
are likely toqualify as acts of competition with younger women.
These include the enforcement of modestycodes, the use of seclusionary
measures, the enforcement of age-based hierarchies, and the use
ofsigns of sexual availability and material and social resources
to attract males.
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Romance Tourism: A Challenge to Evolutionary Theories of Female
Sexual Psychology?
April Gorry
Department of Anthropology,
University of California, Santa Barbara
6500apri @ ucsbuxa.ucsb.edu
The following study concerns the mating behavior of Caucasian
tourist women vacationing intropical locations such as the Caribbean,
East Africa, Indonesia and Greece. The widespreadoccurrence of
a phenomenon that cannot easily be explained by evolutionary theory
makes femaleromance tourism worthy of ethnographic attention.
An initial three month period of field researchconducted in the
Caribbean has revealed the following behavioral anomalies: tourist
women tendto engage in more promiscuous behavior than they would
at home, taking one or more different lovers in the span of a
few days, choosing men of lower status than themselves, providingpayrnent
for "romantic services," and prioritizing male appearance
and reputed love making abilityover other mate selection criteria.
They show a strong preference for dark skinned Rastafarianmen
who they describe as "manly," "exotic," "primitive,"
and "taboo." The women attribute their behavior to the
effects of a novel environment where the opportunity for romantic
and sexualrelationships is plentiful and where their actions will
only temporarily effect the way they areviewed by others. The
above set of findings provide an important test of the ability
of evolutionary models to explain the mating psycholqgy of women.
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Products Liability and Evolution
Mark F. Grady
UCLA School of Law,
405 Hilgard Ave.,
Los Angeles, CA 90024
Telephone: (310) 206-8251 Fax: (310) 206-7010
E-mail: grady@law.ucla.edu
The common law can be conceived as a grown order, like a biological
system. As such it issubject to its own equilibrating mechanisms.
This paper explores the fate of an idea that wasintroduced into
the law of tort during the 1960s, namely, the idea of strict liability
for productdesign defects. What stories did the judges tell as
a justification for this type of liability? What wasthe precedential
basis for it? How did the common-law process evolve this idea
into somethingdifferent from what the originating judges expected
and planned?
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Women's Mate Preferences Across Contexts
Heidi Greiling
Department of Psychology,
University of Michigan
Ann Arbor, MI 48109- l 109
E-mail: Heidi.Greiling@um.cc umich.edu
This paper explores how women's mate preferences are influenced
by different mating contexts,specifically long-term and short-terrn
mating contexts. Particular attention has been paid todifferent
types of short-term mating. Individual differences among women
are also addressed.Discussion focuses on evidence for a extra-pair
short-term mating psychology in women.
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Delusional and Somatoform Disorders as Possible Examples of Intraspecific
Batesian Mimicry in Humans
Ed Hagen
University of California Santa Barbara
6500ehh@ucsbuxa.ucsb.edu
Delusional and Somatoform Disorders (DD, SD) are hypothesized
to be adaptations designed tomitigate the consequences of social
exclusion and other cooperative deficits. They allow sociallythreatened
individuals to parasitize others by exploiting the "host's"
cooperative mechanisms.Individuals with DD or SD closely mimic
conditions where conspecifics are likely to providecooperative
benefits, e.g. defense. This mimetic hypothesis accounts for every
clinical,epidemiological and demographic aspect of Delusional
Disorder: the presence of delusions, thespecific categories of
delusions, the emotional involvement with delusions, the lack
of impairedfunctioning, the distribution of age-of-onset, the
association with immigrant and lowsocioeconomic status populations,
and the apparent etiological role of social isolation andexclusion
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Cheating on Evolution: Emotions and Anti-Habituation
Michael Hammond
Department of Sociology
University of Toronto,
203 College St.,
Toronto, Canada M5T lP9
Emotional habituation is the decline of affective arousal that
occurs with the repetition ofemotionally moving actions during
a given period of time. In other species, it is evolution'ssafety-valve,
limiting the pursuit of similar actions offering positive affect.
In humans, it is also anonconscious physiological constraint on
expanding needs. If basic needs are met, a declininghabituation
curve means that for an individual, additional actions will take
on the average moreand more effort to have a significant affective
impact. Expanding needs therefore require ananti-habituation strategy
to cheat on evolution by reducing that additional labor. Suchlabor-saving
means are generally not available in small scale hunting and gathering
cultures. Atthis scale, the ratio of additional labor to affective
rewards discourages much in the way ofpursuing expanded needs.
This is one reason why most of early human history exhibits so
little inthe way of expanded needs. There are basically two anti-habituation
techniques for larger scalecultures--using expanded inequality
or technology to alter this ratio.
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A SCHEME FOR FORMALIZING EVOLUTIONARY EPISTEMOLOGY
William Harms
Department of Philosophy
University of California, Irvine,
CA 92717
wfharms@uci.edu
ABSTRACT: In order to be able to understand how selection pressures
on cultural items such asscientific theories could end up increasing
the theories' confommity to the world (that worldwhich determines
selection pressures on genes) we need to be able to think clearly
about therelationship between selection processes on genetic and
cultural levels. I am developing a formaltheory of "selection
networks" to aid in this task. The basis of the theory is
the discrete "replicator dynamics", simplified and extended
to model relationships between multiple populations. A measure
of information gain by evolving populations about their local
environment is defined, andcan be extended to reflect information
gain about remote environments. We can, within a singleformal
framework, model gains in information about "the world"
in the distribution of (e.g.)theoretical commitments, as well
as the evolution of the mechanisms which might make such gains
systematic.
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The Opportunity for Romantic Love among Hunter-Gatherers
Yonie H. Harris
Departrnent of Anthropology
University of California, Santa Barbara
or00yoni@ucsbvm.ucsb.edu
Many anthropologists hold the opinion that until fairly recently
in human history parents and otherelders arranged marriages for
young people, leaving little opportunity for romantic love to
play arole in mate choice and reproduction. If romantic love fails
to play any significant role in mateselection over time, how or
why can it remain a part of human nature and how can it beconsidered
a possible adaptation? As the hunting-gathering way of life is
considered the crucibleof the human psyche, a survey of ethnographic
material on hunter-gatherer mateship formationprovides important
insights into the circumstances of ancestral pairings and helps
adjust ourunderstandings of the involvement of romantic love.
A sample of forty-two hunter-gatherersocieties reveals that in
all instances individuals have at their disposal some means to
express theirpersonal preferences and to form either legitimate
or illicit relationships that involve romanticlove.
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Chimpanzee males cry pant-hoots for power
Toshikazu Hasegawa*, Mariko Hiraiwa-Hasegawa** and Sachiyo Kajikawa**
College of Arts & Sciences,
the University of Tokyo,
Komaba, Meguro,Tokyo 153, Japan
(thase@tansei.cc.u-tokyo.ac.jp),
*Institute of Natural Science,
Senshu University,
Kawasaki, 214-80 Japan
Compare to the recent progress in the artificial language training
program, many aspects ofchimpanzee vocalization in the wild have
not yet been fully understood. We analyzed acousticfeatures of
"pant-hoots" by male chimps recorded in Mahale Mountains,
Tanzania, and conductedplayback experiments with a group kept
in an open-enclosure in Japan. We found that 1) thefrequency of
the "climax part" and several other acoustic parameters
changed with male age andthat they were at their highest when
the males were in their 20s; and that 2) dominant individualsresponded
more often than subordinates to the playbacked pant-hoots. The
results suggest chimpsuse pant-hoots to advertise their physical
power rather than to communicate objective informationsuch as
food quality.
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If we all want honest mates why do we deceive them constantly?
Mario Heilmann
Department of Psychology,
University of California, Los Angeles,
Ca 90024.
E-mail: Heilmann@psych.sscnet.ucla.edu
In surveys, about 90% of undergraduate subjects confess having
lied to their partners about topicssuch as fidelity, number of
prior partners, and quality of their mutual sexual experience.
Yet,honesty ranks consistently among the most desired traits we
seek in a mate. The idea that we arehonest is pervasive. We fail
to recognize our deceptive nature. Cues to deception (Ekman) andcheater
detection modules (Tooby & Cosmides), are more acceptable
research topics thanpossible cheating modules, evolved predispositions
for , the ubiquity of lies and the motives fordeception. Richard
Alexander's statement: "human society is a web of lies and
deceit" has notbeen systematically tested in humans. Human
intelligence is probably the result of an evolutionaryarms race
of social manipulation and its detection. Hypocrites, who appear
to be more honest thanthey really are, obtain the advantages of
a good reputation without paying its full cost, andtherefore gain
reproductive advantage. This presentation reviews the literature
from such diversedisciplines as psychology, economics, game theory,
animal behavior, and biology and discussespossible research on
human concealment and falsification, especially in relationships.
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The Cost of Reproduction: Is intermediate fertility ever optimal?
Kim R. Hill
Dept. of Anthropology
Univ. of New Mexico
Albuquerque, N.M. 87131-1086
kimhill@polaris.unm.edu
Empirical data on Ache hunter-gatherers allow us to measure the
costs of reproduction in thatsociety and consider the implications
of those costs. Life history theory assumes that effortexpended
in current reproduction will reduce investment in future reproduction
and survival, andthat each reproductive bout represents an investment
tradeoff between offspring number andfitness. These tradeoffs
should be detectable in demographic patterns, and the character
of suchtradeoffs will determine optimal fertility levels. Such
ideas have led to explicit models of optimalfertility ever since
Lack's work on optimal clutch size. Are such models relevant to
understandinghuman fertility in either traditional or modem societies?
Data suggest that modern fertility levelsare not optimal because
the impact of reproduction on subsequent adult and offspringreproductive
value is extremely low yet individuals behave as if it were high.
Most researchers assume that this is due to an adaptive misfit
between evolved fertility decision mechanisms and therecent modern
context. In this paper I examine with demographic data whether
optimal fertility rates are achieved in hunter-gatherer societies
given the measurable costs of reproduction in thosesocieties.
The results have implications for understanding the true environment
of evolutionaryadaptiveness for fertility decision mechanisms.
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THE AFFECTIONS AND THE PASSIONS
Jack Hirshleifer
Dept. of Economics,
UCLA
Los Angeles CA 90095
hirshlei@econ.sscnet.ucla.edu
Analytic economics has not yet successfully dealt with the affections
(malevolence or benevolencetoward particular others) or the passions
("loss of control" responses to friendly or unfriendlyacts).
The former seemingly violate the self-interest postulate, the
latter the rationality postulate ofclassical economics. An evolutionary
approach allows economics to deal with these phenomena.Hamilton's
inclusive fitness constitutes a broadened concept of self-interest.
One implication:benevolence on the part of a second- mover (parent)
can elicit cooperation from a merely selfishfirst- mover ("rotten
kid"), to the material benefit of both -- provided that the
benevolent partyhas the last move. Even cooperation with a malevolent
partner is possible, provided he is"appeasable". The
passions are still more challenging. Non-rational strategies like
TIT FOR TATare allegedly successful in certain evolutionary contexts,
yet typically fail in competition withrational choice. Various
explanations are considered here.
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Ethics: Adaptation or Byproduct?
Harmon R. Holcomb III
Department of Philosophy,
University of Kentucky
Lexington, KY 40506-0027
Holcomb@ukcc.uky.edu
Francisco Ayala has argued against sociobiological views of morality.
He claims that 1) moralbehavior is a byproduct of intelligence
alone, but morality as such is not an adaptation, 2) moralnorms
are products of cultural rather than biological evolution, and
3) sociobiologists make thenaturalistic fallacy. On the contrary,
Darwin was right that the moral sense is due to bothintelligence
and the social instincts. Darwin held that we are predisposed
to accept the greatest-happiness principle. If we analyze this
predisposition as one to accept whatever functions in a certain
way rather than as a causal mechanism specific to a moral norm,
we can avoid the"culturally versus biologically determined"
fallacy and the naturalistic fallacy.
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Possible Explanations of Maladaptive Cultural Institutions
William Irons
Department of Anthropology,
Northwestern University
1810 Hinman Avenue,
Evanston, IL 60208-1310
w-irons@nwu.edu
This presentation explores three explanations of maladaptive behaviors
that are sanctioned andreinforced by culture: (a) dual inheritance
theories, (b) Robert Frank's theory of hard-to-fake signsof commitment,
and limitations of proximate mechanisms, or proximate mechanism
off-track innovel environment. These theories are not strictly
competing theories since it is possible that someforms of maladaptive
behavior can best be explained by a combination of two or more
* thesetheories. On the other hand, they do lead to somewhat different
predictions that can be used totest the relative power of each
type of explanation. The presentation will outline distinct testablepredictions
associated with each type of explanation.
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Detecting helpers and non-helpers: Their importance in reasoning
about social exchange
Maria G. Janicki
Dept. of Psychology,
Simon Fraser University
Burnaby BC VSA1S6
e-mail: janicki@sfu.ca
Using the Wason Selection Task, Cosmides and Tooby have demonstrated
that subjects do verywell at solving problems that are constructed
in the form of a social contract, in particular,individuals are
very good at detecting violators of social contract rules. The
authors concludethat these results support the existence of innate
rules of inference specialized in cheaterdetection. Although detecting
cheaters has the clear adaptive value of avoiding negativeconsequences,
I argue that having the ability to detect potential helpers and
allies would have alsohad a strong adaptive value in the ancestral
environment. Although Cosmides and Tooby havepreviously tested
for altruist-detection, altruists can be considered a subgroup
of the generalhelping category, just as cheaters can be considered
a subgroup of the non-helper category. Thepresent studies explored
subjects' abilities to detect four types of individuals: altruists,cooperators,
cheaters, and non-cooperators. The results indicate that subjects
seem most able todetect cheaters over the other categories. The
idea that people detect allies using cheaterdetection mechanisms
is discussed.
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Cognition in the Wild:Gaze-Mediated Social Interaction in Pygmy
Chimpanzees
Christine M. Johnson
Departments of Anthropology & Cognitive Science,
University of California at San Diego,
La Jolla CA, 92093-0101
johnson@cogsci.ucsd.edu
The human capacity for theory of mind underlies both language
and culture. Understanding theantecedents of this capacity may
help us develop a more coherent account of our socio-cognitiveevolution.
Developmental research on shared attention and the capacity to
monitor andextrapolate from the gaze of others (i.e. to postulate
that seeing implies knowing) has highlightedthe importance of
visual attention for theory of mind. In this study, we have focused
on gazeinteractions - including eye contact, gaze following, gaze
avoidance, and visual monitoring - inour clc chimpanzee (Pan paniscus).
Frame-by-frame video analysis was done on the coordinationof these
and related social behaviors. By examining the role that gaze
plays in contention overresources, in the expression of social
status, in the solicitation of cooperation, and in apparentdeception
in these animals we can 1) postulate the social conditions that
may have selected for thecapacity to model the knowledge of others
and 2) help create informed experimental designs forassessing
the nature and limits of social cognition in nonhumans.
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THE EVOLUTIONARY ROOTS OF PATRIOTISM
Gary R. Johnson
Department of Political Science
Lake Superior State University
Sault Ste. Marie, Michigan 49783-1699
(GJOHNSON@LAKERS.LSSU.EDU)
From an evolutionary perspective, patriotism is a predisposition
to behave altruistically on behalfof the most comprehensive social
system of which an in&vidual is a member. Human societiesmanufacture
patriotism by attaching their members' individual-level capacities
for nepotism andreciprocal altruism to the system as a whole.
This appears to be achieved through orchestratedmanipulation of
1) kin recognition mechanisms, 2) symbols of reciprocity, 3) symbols
associatedwith important collective goods, and 4) symbols associated
with the collective entities throughwhich these collective goods
are achieved. If this analysis is correct, we call make sense
of thecomplex socialization processes and familiar symbols (flags,
anthems, monuments, holidays, etc.)that prepare humans for altruistic
sacrifice on behalf of their societies. These processes appear
tohave been used universally to help build the alliances through
which humans have pursued theirshared interests. However, in a
world threatened by overpopulation resource depletionenvironmental
destruction and potentially cataclysmic warfare, the brand of
patriotism that servedthe interests of our ancestors might today
contribute to human extinction. It may therefore beessential that
today we begin using these ancient mechanisms of patriotism to
build a morecomprehensive social and political system, a system
that will allow our species to survive in anage that differs so
dramatically from the age when these mechanisms originally evolved.
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"Mirror, mirror, on the wall..."
Victor S. Johnston and Juan C. Oliver-Rodriguez.
Department of Psychology,
NMSU,
Las Cruces, NM 88003
(vic@crl.nmsu.edu).
Both behavioral beauty ratings and affective responses (late positive
components of event relatedpotentials; ERPs) were recorded from
25 male subjects e~posed to 32 male and 32 female faces,presented
in a random order over four experimental sessions. Based on previous
research, thestimulus slides were computer generated faces designed
to examine two levels of eye size (wide &narrow), lip size
(full & thin), chin shape (broad & narrow), hair type
(blonde & black) and lowerjaw proportions (average & short),
for each sex. A late positive component (LPC) of ERPs with aP300
scalp distribution (Pz > Cz > Fz), was reliably correlated
with the beauty rating of femalefaces (r = 0.46; p < 0.008).
Both behavioral and affective responses (LPCs) were influenced
by anumber of features and their interactions. The results are
interpreted as support for a hormonaltheory of female facial beauty.
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PSEUDOPARASITOSIS, IMMUNOPHENOTYPIC PLASTIClTY, AND THE EVOLUTIONOF
AUTOIMMUNE DISEASEM.
C. Jones
University of Misssouri-
Columbia School of Medicine,
Dep't of Psychiatry and Neurology,
#1 Hospital Drive, Columbia. MO 65201
psymcj@mizzou1.missouri.edu
Primate reproduction, social structure, and immunity are inextricably
coupled. Parasite pressurestrongly determines optimal group size,
habitat preference, foraging pattern, grooming behavior,mate selection.
and other life history traits. Antiparasite immunophysiology mediates
facultativeabortion, decreased libido, and other mechanisms that
adaptively suppress host reproduction anddeter contagion. Immune
system cytokines interact with gonadal steroids to mediate similar
skinand joint manifestations in parasitic and rheumatoid diseases,
as well as mediating cyclic displaysof female reproductive condition
such as sternal blistering and genital swelling. The centralcontrol
of such disparate processes via hypothalamic peptides and direct
innervation suggests thatkin selection may have exploited the
network architecture of immunophysiology to createinflammatory
displays modulated by higher cognitive cues that determine rank
breedingopportunity and emotional state. Individual immunophysiology
may thus be entrained by anevolving reproductive socio immunophysiological
structure in which inclusive fitness dividendscould justify the
costs of parasitomimetic inflammatory displays (pseudoparasitosis).Parasitomimetic
displays may involve natural autoantibodies (NAAs) encoded by
germline genes.Autoreactive Iymphocytes (ARLs) producing NMs are
found in normal humans and mice. Thesefactors may help to dispose
of infected cells and corrupted DNA by recognizing crypticautoantigens
exposed during microbial and helminthic parasitoses or during
developmentallyprogrammed cell death. NMs and ARLs are usually
held at low or undetectable levels but theymay be upregulated
by hormonal or neural signals correlating with changes in social
rank andprobability of future reproduction. Thus, considerable
immunophenotypic plasticity may arise inresponse to social cues
correlating with future resource availability and likelihood of
offspringsurvival. Systemic lupus erythematosus (SEE) and rheumatoid
arthritis (RA) support thehypothesis. These classic conditions
display parasitomimetic skin, Joint, systemic and behavioralsigns
and symptoms. They are sexually dimorphic (female >> male),
activated by social stress,modulated by gonadal steroids and prolactin,
and associated with reduced fertility andupregulated NMs. Thus,
some autoimmune phenomena may exemplify how complex mammaliansocial
systems optimize fitness by differentially apportioning reproductive
resources amongmembers.
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Evolution, Value Clarification, and Legal Policy
Prof. Owen D. Jones
Arizona State University,
College of Law
Tempe, AZ 85287-7906
E-mail: Owen.Jones@asu.edu
Law is fundamentally about the regulation of human social behaviors.
Evolutionary perspectivescan contribute to the pursuit of pre-articulated
legal goals by illuminating potential origins ofthose behaviors.
Every legal policy imposes costs, and political actors often decide
whether topursue a given policy by estimating whether potential
benefits will outweigh those costs. Insightson the origins of
certain behaviors can therefore help refine legal policy by identifying
previouslyunconsidered costs or benefits. Sometimes this will
reveal previously unaddressed tensionsbetween co-existing policies,
such as preventing even a single infanticide, on the one hand,
andnot stigmatizing step-parents, on the other. Bringing this
tension into focus may require us todefine the value underlying
one policy in terms of the values underlying the competing policy.While
evolutionary perspectives provide no normative guidance on how
to resolve such policyconflicts, they may help assure that such
resolution is better informed.
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Distributing Property at Death: Sex Differences in Rules or Realities?
Debra S. Judge
Department of Anthropology,
University of California Davis,
CA 95616.
dsjudge@ ucdavis.ucdavis .edu
Sex differences in observed behaviors do not necessarily reflect
sex differences in behavioral goalsor operational rules. Sex specific,
demographic conditions may require different behavioralmechanisms
to accomplish similar outcomes. A sample of 20th century California
men and womenexhibit few differences in property allocation at
death that are due to inherently differentallocation rules. Neither
sex prefers either sons or daughters. Both sexes prefer nearest
kin butdecrease proportions of estates to such kin as they become
more distant. Women include morebeneficiaries and are more likely
to specify particular items of property for particular recipients;men
are more often formulaic and include fewer beneficiaries. The
most striking differencesbetween men and women in property allocation
occur within the nuclear family and reflectdifferences between
spouses in reproductive lifespan that result in reproductive conflicts
that canendure beyond death.
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Competitive labor markets and modern fertility: An evolutionary
economic theory
Hillard Kaplan and Jane B. Lancaster,
Department of Anthropology,
University of New Mexico
Hkaplan@unm.edu, Jlancas@unm.edu
This paper presents tests of hypotheses derived from the competitive
labor market theory ofmodern fertility and parental investment.
The central hypothesis derived from the theory and tobe tested
here is that when income is earned through participation in competitive
labor marketswith skill- and knowledge-based relationships between
production technologies, the functionalrelationships between parental
investment and child outcomes have two special properties. First,investments
in the adult income of children yield either constant or increasing
returns to scale, atleast through a large part of the range of
investments. This is due to the forces of supply anddemand in
wage determination. Second, higher-earning parents are expected
to have higher ratesof return on investments in offspring income.
These two conditions are proposed to produce verylow fertility
rates, a positive correlation between income and parental investment;
and a null relationship between income and fertility. These propositions
are tested with a representativesample of 650 men from Albuquerque,
New Mexico. The data show that men with higher levelsof human
capital, as measured by education and income, invest more time
in their children whenthey are young than do men with lower levels
of human capital. Men's human capital is alsopositively related
to rates of return on investment in children as measured by school
grades,education, and adult income.
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Modeling Stress and Arousal as Adaptations
Charles N.W. Keckler
Human Evolutionary Ecology Program
Dept. of Anthropology,
University of New Mexico
E-mail: cnwk@hydra.unm.edu
Stress reactions have long been considered as homeostatic or as
the inevitable and negativephysiological effects of environmental
insults. An initial optimality formalization of the moreevolutionary
perspectives of Nesse, Sapolsky and others is conducted that considers
stress aspreparatory to possible future needs for the support
of heightened motor activity. In theanomalous case of social anxiety,
two hypotheses are evaluated: (1) it is a maladaptive relic of
asystem where fight and flight was more common or (2) it is an
honest, costly signal (in thegame-theoretical sense) of social
arousal. A concluding discussion considers how to field testthese
models, and suggests a Darwinian psychophysiology may be useful
in overcomingmethodological problems such as the role of subjective
states and observer bias.
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Title: Parent-Offspring Conflict as a Selection Pressure for the
Evolution of Early Language Acquisition
Authors: (I) David Kemmerer,
(2) Patrick McNamara Affiliations:
( I) SUNY Buffalo,
(2) Buffalo State College Address:
( I) Department of Linguistics,
685 Baldy Hall,
SUNY Buffalo. Buffalo. NY 14260
E-mail: (I) V323MV3N@ubvms.cc.buffalo.edu
Language is acquired extremely early, rapidly, and efficiently
by children - so well, in fact. thatlanguage acquisition is an
excellent candidate for being a specialized cognitive adaptation
(Pinker1994). We argue that a major selection pressure for the
evolution of early language acquisitionwas the recurrent adaptive
problem of parent-offspring conflict (Trivers 1974). According
to this hypothesis, hominid children who acquired language early
could have used it as a strategy for (I)psychologically manipulating
their parents into providing greater investment than they are
selectedto provide. and (2) resisting their parents' attempts
to make them do things that are more in theparents' genetic interests
than the children's (e.g., altruism toward sibs beyond a certain
point).Early linguistic skills could thus have enhanced hominid
children's fitness (RS) and been selectedfor. We present several
forms of evidence in support of our hypothesis. including the
following:the period when language acquisition occurs coincides
perfectly with the period of weaning in theEEA, weaning being
the time when parent-offspring conflict is most intense; many
of the brainareas that are involved in language acquisition are
also involved in attachment and other socialrelations; one of
the major functions of communication systems in other species
is to enablesenders to manipulate receivers, especially in the
context of solicitations for caretaking; finally,many researchers
have shown that children actually do use language to a considerable
extent tomanipulate their parents through such tactics as crying,
teasing, begging, joking, boasting,exaggerating, lying, resisting,
denying, and arguing. In addition, we describe a number ofpredictions
that follow from our hypothesis. Overall, our hypothesis constitutes
a detailed attemptto explain the evolutionary origins of a well-known
cognitive adaptation - early language acquisition - in terms of
a well-known adaptive ploblem - parent-offspring conflict.
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EMOTION AS A MENTAL REPRESENTATIONS OF FITNESS AFFORDANCES I:EVIDENCE
SUPPORTING THE CLAIM THAT NEGATIVE AND POSITIVE EMOTIONSMAP ONTO
FITNESS COSTS AND BENEFITS
Timothy Ketelaar
NIMH
Postdoctoral Training Program in Emotion Research,
Department of Psychology,
University of Illinois,
Champaign, IL 61820
Recently Tooby and Cosmides (1990) proposed that emotion systems
are likely to show evidenceof being designed to solve the adaptive
problem of representing the cost-benefit structure ofancestral
environments. They argue that because information is the most
important resource thatorganisms compete for across the adaptive
landscape that evolution is likely to have equipped uswith specialized
mechanisms that assign hedonic values--or subjective utilities--to
cost and benefitcues. Moreover, they have argued that these specialized
information foraging devices correspondto emotional- adaptations.
Although intriguing and compelling, their paper presents no directempirical
evidence to support their model. The current paper: 1) elaborates
their model and 2)provides empirical evidence (from five experiments)
supporting their claim that affects/emotionscorrespond to mental
representations of cost-benefit cues. This evidence is in the
form of experimental results showing that emotional reactions
to imagined costs and benefits correspond to the assumptions of
Prospect Theory (Kahnman & Tversky, 1979), the leading psychologicalmodel
of cost-benefit reasoning.
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EMOTION AS MENTAL REPRESENTATIONS OF FITNESS AFFORDANCES II: DOES
ANGER MAKE YOU MORE RATIONAL?
Timotby Ketelaar and Gerald C. Clore
Department of Psychology,
University of Illinois,
Champaign, IL 61820
It is argued that because affective states have a legacy of being
considered 'irrational' mentalprocesses--diametrically opposed
to more 'rational,' emotional-less processes--that a program ofresearch
which investigates the role of emotion in reasoning has the potential
of shedding somelight on the seeming rationality or irrationality
of human decision making. Of specific interest isthe role that
"anger" plays in the domain of social contract reasoning
and cheater detection. Thispaper proposes that at a more domain
specific level of analysis, particular affective states (e.g.,anger,
fear, joy, etc.) refer to mental representations of cues to particular
types of fitness costsand benefits. For example, researchers who
adopt a cognitive perspective on emotion (Ortony,Clore, &
Collins, 1988) have proposed that "anger" involves cognitions
pertaining to 1) actions ofsocial agents, 2) violations of social
standards, and 3) the assessment of blameworthiness. It is asmall
leap of inference from these assumptions to the prediction that
anger (compared to neutralmood) will facilitate reasoning in the
Cheater Detection Paradigm (see Cosmides & Tooby, 1992).Preliminary
evidence is presented which suggests that the psychological state
of anger facilitatedperformance on a general reasoning task (the
Wason Selection task). Moreover, this effect wasstrongest for
Males and was especially evident for problems framed as Social
Contracts whichafforded a potential for cheating
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SYNTAX ORIGINS: A DARWINIAN SIGNAL-EVOLUTION PARADOX.
Chris Knight
Dept. of Anthropology & Sociology,
University of East London,
Brooker Building,
Longbridge Rd.,
Dagenharn, Essex RM8 2AS, England.
email: Knight@uel.ac.uk
Darwinian signal-evolution theory distinguishes between honest
and deceptive signals.Communicators in conflict anticipate deception,
ignoring signals unless loud, repetitive,multi-media - costly.
Human 'ritual' fits such descriptions, suggesting an adaptation
forovercoming significant listener-resistance. Use of a conventional
code by contrast relies on trust,shared interests. 'Speech' is
correspondingly efficient, vocal-auditory, cryptic, low-cost.Syntactical
complexity in such signaling is unique. It's the design hallmark
of an adaptation forcommunicating about virtual phenomena --the
Dreamtime, the Future, God, etc.Hunter-gatherers plug into their
virtual worlds via deceptive ritual. Primates (and by inference,early
humans) lack this, knowing nothing of the corresponding collective
representations. Wheresignals can map only to perceptual representations,
listeners may always infer supplementary datafrom real-world contextual
cues. But 'the gods' operate outside space and time. To converseabout
the unseen agency of these, reconnecting such intangibles to the
real world, signalers mustelaborate, specifying spatiotemporal
relationships--the novel function of grammar. I conclude thatthe
ancient innate structures underpinning syntax were late to invade
the vocal-auditory channel,doing so only as magico-religious ritual
set up selection pressures to communicate honestly about communal
deceits
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Female Sexual Jealousy in The Crime of Padre Amaro: Evolutionary
and Feminist Approaches Melody L. Knutson
Department of Anthropology
University of California, Santa Barbara
knutson@alishaw.ucsb.edu
The application of evolutionary theory to literary studies is
a trend that is gaining in popularity,especially given the perceived
sterility of the dominant post-structuralist paradigm. However,current
gaps in the evolutionary interpretations of female sexuality in
general and female sexualjealousy in particular limit our ability
to analyze the rich range of female behavior and emotionencountered
in literary texts. The proposed paper explores the patterns of
female sexual jealousyexhibited by the character of Amalia in
Eca de Queiros' The Crime of Padre Amaro using anevolutionary
framework. I suggest that an evolutionary reading of the novel
that is informed by afeminist critique may help bridge some of
the current theoretical gaps.
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Gene-Culture Coevolution: Sex Ratio Distorter Genes and Culturally
Transmitted Sex Bias
Jochen Kumm,
Department of Biological Sciences,
Stanford University
Gene-culture coevolutionary theory has been developed specifically
to explore the interactionbetween genetic and cultural processes.
The theory builds on standard population genetics modelsby formally
incorporating cultural transmission into the analysis.I present
a case study, which explores culturally transmitted traits --
such as female infanticide,sex -biased abortion and sex-selection
-- that increase the mortality of female offspring. At thesame
time I consider genes which may distort the sex sex ratio of a
mating. Through acombination of analytical and computational approaches,
I explore the co-evolution of bothcultural biases and sex ratio
distorter genes which affect the adult sex ratio in a population.
Male-or female-biased sex ratio alleles can invade depending on
whether a cost is associated withgender bias. A rich set of dynamics
leading to male- or female-biased primary sex ratios, oroscillations,
results from the interaction of genes and culture. The dynamics
and stability of thegene-culture system depend sensitively on
the transmission rules for cultural inheritance. Similarlythe
trajectories of allele- and cultural phenotype frequencies depend
on whether distorter genesare located on autosomes or sex chromosomes.
In the latter case, cultural biases against femalesmay protect
the population against alleles which introduce extreme sex ratios.
I show that gene-culture co-evolutionary theory can be used to
analyze the diffusion of cultural traits and geneticvariation
through populations and to explore the interaction between cultural
sex biases and genetic sex ratio distorters.
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Detecting Coalitions: Evolutionary Psychology and Social Categorization
Robert Kurzban*, John Tooby & Leda Cosmides
Centerfor Evolutionary Psychology, University of California, Santa
Barbara, CA 93106 kurzban@psych.ucsb.edu, tooby@alishaw.ucsb.edu
Converging evidence from many sources indicates that ancestral
hominids lived embedded in acomplex alliance structure of existing,
emerging, and potential coalitions. We propose that thisenvironment
selected for cognitive specializations in the human mind that
automaticallycategorized members of the observed social world
into underlying groupings whose membershipand boundaries were
psychologically real and consequential to the participants. Extracting
andmemorizing correct inferences about this alliance structure
from daily observations anevolutionarily significant task with
profound and enduring fitness consequences. Using anexperimental
paradigm developed from Taylor, Fiske, Etcoff, and Ruderman (1978),
we havebegun to test hypotheses about the existence and design
of alliance detection mechanisms. Resultssuggest that when subjects
observe a novel individual, they l) automatically and implicitly
makeinferences about which coalition he belongs to, and 2) automatically
store, along with otherinformation they acquire about the individual,
his inferred coalitional membership. They do thiseven in the absence
of perceptual cues of coalitional membership (e.g., physical appearance,clothing),
although such cues appear to be used when they are present and
if they are predictive.Subjects appear to do this as incidental
learning even on tasks where successful performance hasnothing
to do with coalitions or coalitional membership; moreover, as
predicted the tendency toinfer coalitions appears to be more pronounced
in men than in women.
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Evolved Fur Attractiveness
Lisa LaRue
Unaffiliated1972 Las Canoas Rd. /
Santa Barbara, CA
People like to look at fur. This phenomenon reveals a mental adaptation
for preferring to live with(and domesticate) companion animals,
especially cats and dogs. The possible benefits for this traitcould
be a reduction of parasitic micro-organisms in the local environment
due to thedomesticated animals predating on pest species that
often carry and transmit diseases. Anotherpossible function of
this preference may be to deter wild, non-domesticated animals
fromapproaching and interacting with human resources (e.g. the
presence of guard dogs within cattleherds prevent wolves from
predating on the cows). Evidence for this adaptation comes from
thefact that "furry" is perceived as cute in the same
way that baby features are. Also, velvet (amanufactured fur-substitute)
is valued for the aesthetic visual enjoyment it stimulates. In
fact,paintings on velvet are so sensually enjoyable to the human
eye that they may be consideredhedonistic in some societies. Human's
visual enjoyment of fur is closely related to humans'preference
to touch fur and soft things. Some may explain this as a preference
for touching humanbabies. However it must be noted that cats are
much softer than human babies. Also peoplefrequently initiate
touch and stroking to any dog or cat who does not display aggression
(and theact of petting a dog has been scientifically proven to
relax the nervous system); while people onlytouch familiar babies,
and, when they do, not to the same extent that they pet their
pets.
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Arousal and Attraction: Reproductive Potential Versus Threat Assessment.
Brian P. Lewis, Darwyn E. Linder & Douglas T. Kenrick
Arizona State University, Tempe, AZ. 85287-1104
E-Mail: AGBPL@ASUVM.INRE.ASU.EDU
Three studies were conducted to examine the nature of the relationship
between physiologicalarousal, sensual attraction, and gender.
Evolutionary theory suggests that for males encounteringan attractive
female, sexual attraction is the dominant response. Thus, males
should be moreattracted to any attractive female when arousal
is heightened. For females, however, the samerelationship may
not hold. The dominant response of females encountering an unfamiliar
male maybe to assess the potential threat posed, rather than the
target's potential as a mating partner. Male and female subjects
rated two targets (a stranger and current dating partner) under
differing levelsof physiological arousal. Consistent with a dominant
response perspective, males' sexual attraction toward a stranger
increased with arousal. Consistent with our predictions, females'
exhibited adifferent dominant response, rating unfamiliar targets
less friendly and more threatening whenarousal was heightened.
Females' rating of a familiar target, their current mate, were
unaffected byarousal. In a subsequent study, female assessment
of threat and security differed when rating afamiliar other compared
to a stranger, and these differences were more extreme under conditionsof
heightened arousal, offering additional support to our predictions
that the adaptive response forfemales encountering a stranger
is different than that for males.
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The Frequentist Reasoning Hypothesis: How Significant is the Effect?
Tracy L Lindberg, Charles Crawford, & Cathy McFarland
Dept. of Psychology,
Simon Fraser University,
Burnaby, B. C., CANADA V5A lS6
e-mail: lindberg@sfu.ca
Research in social cognition, particularly that dealing with judgment
under uncertainty, has established the existence of many cognitive
biases and fallacies in human reasoning, such as base-rate neglect.
Cosmides and Tooby have argued that these studies are based on
a Bayesianinterpretation of probability, whereas an evolutionary
perspective would predict cognitive mechanisms to be frequentist
in nature. Using a frequentist version of a problem well-known
foreliciting base-rate neglect, Cosmides and Tooby concluded that
objects were good intuitive statisticians. The studies presented
here were designed as a three-part investigation into theFrequentist
Hypothesis Effect reported by Cosmides and Tooby. The goals of
the investigation were as follows: (1) to test the replicability
of the frequency effect; (2) to isolate the effect of the frequency
presentation from the effect of confounding variables; and (3)
to re-examine how wellsubjects' reasoning reflects aspects of
a calculus of probability, such as Baye's rule.
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EVOLVED PSYCHIC STRUCTURE & DREAMING
Alan T. Lloyd, M.D.
9810 FM 1960 Bypass,
Suite 280
Humble, TX 77338
Recent theories regarding the function of dreaming (REM sleep)
emphasize its role in informationprocessing and memory consolidation.
A phylogenetic model is reviewed in support of this view.The strongest
evidence supports the processing and consolidation of emotionally
important eventsand memories in humans during dreaming. Evolutionary
interest in the adaptive significance of and self-deception
has led to the newly developing field of evolutionarypsychodynamics,
which presupposes that universal evolved psychic structures regulate
the use ofdeception as individuals strive to maximize inclusive
fitness in their inter-relationships. Dreamingis proposed to be
an evolved, active mechanism which facilitates the integration
of currentexperience and its varied implications with our conscious
and unconscious models of self andothers. Remembered and recounted
dreams may serve important functions as antirepressivedevices
and encoded communications. The response of others to the recounting
of dreams may beconsidered part of the current experience towards
which the dreamer must adapt. Finally, possibleimplications for
developing evolutionary models of change are considered, including
the potentially privileged role of dream interpretation.
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Eugenics as a Component of Judaism as a Group Evolutionary Strategy
Kevin MacDonald
Department of Psychology
California State University-Long Beach
Long Beach, CA 90840-0901
KMACD@BEACHl.CSULB.EDU
Individual differences in intelligence are associated with differences
in a wide range of adaptive behaviors related to resource control
and social status in contemporary societies, and evidenceprovided
here suggests this has also been the case in historical stratified
societies. Further,intelligence is one of several highly heritable
individual difference dimensions which areuniversally viewed as
resources in human mate choice, suggesting the evolution of mechanisms
for the appraisal of individual variation. Ashkenazi Jews have
the highest measured intelligence ofany known human group, with
data suggesting a full scale IQ of approximately 117 and a largegap
between verbal and performance IQ scores compatible with an average
verbal IQ in the 125range. Judaism is here conceptualized as a
group evolutionary strategy in which there have beenpowerful social
controls on the behavior of individuals to confront to group norms,
particularlywithin-group altruism and endogamous marriage. Here
I emphasize the hypertrophied status ofintelligence as a criterion
of mate choice enshrined in religious ideology as well as actual
practicefor approximately 2000 years. Wealthy men were enjoined
to marry their daughters to males whohad proved themselves as
scholars. Scholarship was not only the route to a good marriage,
it wasalso the route to, wealth, high social status, and relatively
high reproductive success for Jews intraditional societies.
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Reproduction and heritable wealth in nomadic pastoralists.
Ruth Mace
Dept of Anthropology,
UCL,
Gower St, London WClE 6BT, UK
Email: ucsadrm@ucl.ac.uk
Data from 1000 Gabbra pastoralist families are used to investigate
the effects of wealth and anumber of other variables on the number
of children in families. The results are compared withthose predicted
by optimality models used to predict the family sizes that are
expected tomaximize the reproductive success of parents, given
that there is competition between theirchildren for their resources.
I will use the results to argue that parents do indeed makereproductive
decisions regarding their fertility, even in non-contracepting
populations.
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Legal Resources in Behavioral Research: General Opportunities
and Moot Court - A Case Study
Cam MacRae and Oliver R. Goodenough
Vermont Law School
Chelsea Street South Royalton,
VT 05068
cmacrae@vermontlaw.edu
The workings of a legal system are necessarily examples of human
behavior. The U.S. legalsystem is relentlessly self-documenting.
Trial transcripts and judicial decisions provide a richtrove of
"wild" behavioral information. Large bodies of this
data have been computerizedcommercially in searchable form. These
companies often make the data available for free toacademic researchers.
The recent introduction of audio and video taping into many courtroomspreserves
an even more diverse body of data. Topics such as "Judge
Ito as Alpha:Aggressive/Submissive Displays in the Simpson Trial"
become researchable at relatively low cost.In a case study at
Vermont Law School, we have examined data from existing videos
of mootcourt practice arguments to study gender differences in
legal argument of the kind which might beinferred from the theorizing
of Carol Gilligan.
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Attachment and Maternal Compensation with High-Risk Infants: An
Ethological Study
Janet MannCenter for Advanced Study in the Behavioral Sciences
202 Junipero Serra Blvd.
Stanford, CA 94305;
Department of Psychology
Georgetown University
Washington D.C. 20057
Email: Mann@casbs.stanford.edu
Laboratory and survey studies have found three distinct types
of parental responses to high-risk preterm infants, characterized
as 1) abuse; 2) overstimulation, and; 3) compensation. This study
investigates behavioral interactions and attachment patterns among
mothers and their extremely low birth weight (ELBW, birth weight
<1250 grams) preterm infants during the first year of life
to determine which of these models of parental behavior is best
supported. ELBW twin infants were conducted at 4- and 8-months
of infant age (corrected for gestational age in the ELBW group)and
attachment assessments were done at 14 months. Analyses of group
(ELBW vs. full-term)behavioral differences supported the "compensation
hypothesis". Mothers were more attentive tohigher-risk infants
compared to lower-risk infants, although the nature of this involvement
differe ddepending upon the child's characteristics. ELBW infants
who experienced neurological insultreceived more proximate stimulation,
whereas ELBW infants who experienced severe respiratoryproblems
received more distal stimulation at eight months. However, under
more stressful circumstances, such as with ELBW twins, mothers
gave preferential treatment to their healthier infant. Overall,
mothers of preterm infants are best characterized as adjusting
to, not insensitive to, infant signals and characteristics. Conditions
favoring high vs. low maternal investment in highrisk offspring
are explored.
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Rules and Statistics: An Evolutionary Perspective
Gary F. Marcus
Department of Psychology
University of Massachusetts,
Amherst
E-mail: marcus@psych.umass.edu
This paper argues that two complementary computational mechanisms
are recruited throughoutcognition: a statistical resemblance mechanism
that extracts and tabulates contingencies and a rulemechanism
that treats all members of a class equally, suppressing differences
between individualmembers.Although these two domain-general computational
mechanisms are combined in domain specificways, I argue that both
are indispensable in many domains, including language, speech
perception,object recognition, categorization, deduction, induction,
formal reasoning, social stereotyping,and mental arithmetic.I
concur with Kelly & Martin (1994) that statistical mechanisms
are adaptive, providing organismswith a way to cope with a probabalistically
structured environment. But, I suggest that the rulemechanism
is also adaptive: it underlies a calculus of individuation and
identification that allows organisms to suppress irrelevant information,
focus on relevant information, and draw inferencesthat are likely
to be true of every member of the group, even individual members
that have not previously been encountered.
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Kin Recognition, Emotion, and Ethnocentrism
Roger D. Masters
Dartmouth College -
Department of Government
Silsby 6108
Hanover. NH 03755K
in recognition mechanisms shape sense perception during normal
development. These preconscious cues elicit emotions that can
be redirected to ethnic or national groups, allowinglarge scale
societies to overcome the selective disadvantage of cooperation
with anonymousnon-kin. Ethnocentrism, in the form of a preference
for behaviors encountered during childhood,seems to be a cultural
universal. Nationalism, reinforced by symbolic association with
a fictivegroup, presupposes an optimistic view of the rewards
of future social interaction. Xenophobiaarises when fear or uncertainty
undermines this optimism and erodes learned respect for thosewho
differ from expected preconscious cues. Experimental data confirm
these emotionalprocesses and the role of learning in social cooperation
and the rule of law.
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Comparative Studies of Uncertainty and the Law
Michael T. McGuire
UCLA -
School of Medicine
Neuropsychiatric Institute
760 Westwood Plaza
Los Angeles, CA 90024
mtm@npih.medsch.ucla.edu
Data from field and laboratory studies of uncertainty -- ambiguous
stimuli -- will be presented.These data show specific CNS responses
to ambiguous stimuli as well as specific physiological responses.
Proximate mechanisms and behaviors for uncertainty reduction will
be described, andlaws dealing with uncertainty and risk will be
analyzed.
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Birth Order and the Naming of Children: An Examination of Naming
as a Strategy of Parental Investment.
Frank T. McAndrew & Jennifer L. Cooley,
Knox College.
Previous research has indicated that naming children after parents
or other relatives may be astrategy of parental investment that
advertises the inclusion of children in the kinship group andincreases
the likelihood of investment of resources by fathers and other
relatives. It is most likelyto occur in situations in which actual
genetic relatedness is lacking(i.e., adoption) or less certain(children
are more likely to be named after fathers than mothers). This
hypothesis was pursued ina study that examine the relationship
between namesaking of children and variables such asdivorce rates
of parents, birth order and number of children in the family,
and whether or not theparents themselves had been named after
other relatives.
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.
Evolution of Sociopathy
Linda Mealey
Department of Psychology
College of St. Benedict
LMEALEY@CSBSJU.EDU
This poster outlines a dual-pathway model of the evolution and
development of sociopathy which will appear in full, with commentary
and rejoinder, in the September, 1995 issue of Behavioral and
Brain Sciences. The model integrates the "proximal"
explanations of sociopathy from thefields of behavior genetics,
child development, personality theory, learning theory, and socialpsychology,
with the "ultimate" explanations from evolutionary and
game theoretic models. Two distinct developmental etiologies of
sociopathy are posited to be maintained by two different evolutionary
mechanisms, creating what Dawkins refers to as "phenocopies".
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Policy Implication Implications of Male Status Seeking
Edward M. Miller
University of New Orleans
New Orleans, LA 70148
A standard sociobiological argument is that humans, especially
males, have evolved to seek signsof status. This is usually explained
by high status individuals enjoying greater reproductive success.
Two implications results from this. One is that it may be desirable
to tax heavily goods that bring status. Individuals frequently
strive mightily to acquire signs of status, such as fancycars,
jewelry, large homes, titles, etc. In a modern economy these goods
derive most of their value from their prices rather than the physical
service they render. Thus, it is possible to extracts ignificant
revenue without reducing the utility experienced by the purchaser
of the goods. The other implication is that sex differences in
the striving for status may be real. In this case optimal decision
making implies that knowledge of group membership will be relevant.
If as appears to be the case, female scientists publish less (presumably
due to deriving less reproductive benefit) from the status publishing
brings, this might be relevant to decision making. In theory,
the optimal estimate of the future productivity is a weighted
average of prior belief based on the individual' ssex and indicators
of individual productivity.
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Darwinian demographics of cultural production
Dr. Geoffrey F. Miller
Psych. Dept.,
Univ. Nottingham
NG7 2RD, England,
gfm@psyc.nott.ac.uk
After 8/95: Max Planck Institute, Leopoldstr. 24, 80802 Munich,
GermanyMental adaptations for human creativity and culture (e.g.
language, art, music) may have evolvedlargely under runaway sexual
selection. If so, we might predict strong sexual dimorphism and
distinctive, sex-specific life history patterns (age profiles)
in rates of cultural production. Data onworks produced per individual
per annum were gathered by random sampling from biographical dictionaries
for : around 30 philosophers, 200 fiction and non-fiction writers,
30 classical musiccomposers, 300 rock musicians, 400 jazz musicians,
and several other populations. In each case,data supported the
runaway theory: (1) males produced over 80% of all cultural displays,
(2)males showed a peak cultural productivity between ages 20 and
30, corresponding to other peakssexual competitiveness (e.g. strength,
homicide rates), and (3) females showed a later, broader,peri-menopausal
peak. The sexual payoff for cultural production will be illustrated
with severalexemplars (e.g. Balzac, Liszt, Chaplin, Hendrix).
The data contradict other theories that culturalproduction functions
mainly to promote social cohesion, class oppression, or cross-generational
information transfer. Cultural production is mostly sexual display
by young males.
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An Experimental Publication Utilizing the Web to Facilitate Scholarly
Communication and Peer Review: The Journal of Evolutionary Psychology
Michael E. Mills
Psychology Department
Loyola Marymount University
Email: mmills@lmumail.lmu.edu
As a platform for publication of a scholarly journal, the World
Wide Web will soon offer scholars valuable functions that are
unavailable via traditional print publications. This paper discusses
major future advantages of scholarly publication via the Web.
addition, the initiation of a new electronic publication, the
Journal of Evolutionary Psychology, is discussed.This new Web
journal will serve as an experiment for innovation electronic
publication, as well asserve scholars the discipline of evolutionary
psychology. Some novel features to be offered byjournal will include:
(a) databases of quantitative reviewer and readership evaluations
for eacharticle, (b) text-bases of reviewer and reader comments,
as well as author responses to thesereviews, searches based on
quantitative ratings by reviewers, keyword, and full text, (d)
accessto (and archival of) original research data, and, (e) the
incremental construction of a summary"knowledge base"
for the discipline. Authors interested contributing their work
to this new journal should email the author at the above address.
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Characteristics of Personals Ads Differ as a Function of Publication Readership
SES
Michael E. Mills Psychology Department Loyola Marymount University
Email: mmills@lmumail.lmu.edu
Previous research has found that
advertisers' self-description, and desired partner attributes, in personal
ads published newspapers or magazines are generally consistent
with the gender differences predicted by evolutionary psychology.
The purpose of this study was to assess how these ads differ in publications
targeting readerships of different socio-economic status (SES)
levels. Content analyses of personals ads were conducted using
publications targeting specific SES readerships. It was found that:
(a) although more males than females placed ads, the proportion
of females placing ads was greater higher SES publications, (b)
proportionally more young males placed ads in low SES publications,
more females than males declined to state their age, particularly
high SES publications, (d) proportionally more males advertising
high SES publications expressed a desire for a younger partner
than male advertisers low or middle SES magazines. These and other
findings are discussed with respect to predictions made by evolutionary
psychology.
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Homo provocans: the "missing link" toward the solution
of the domain-general vs. domainspecific controversy?
Peter Molnar and Emese Nagy
Semmelweis Medical University,
Institute of Behavioral Sciences,
Budapest, Hungary
email address: molpet@net.sote.hu
While the controversy over the relative weight of domain-general
vs. domain-specific componentsof our evolutionary legacy is still
to be settled, new data coming from interdisciplinary researchprograms
-- including ours -- on newborn-mother interactions might supply
new possibilities for adialectic solution. A fine grain analysis
of the so called Meltzoff-Moore effect (i.e. astonishingimitative
capacity of newborns, including mirroring at least three of six
basic emotions), usingsplit-screen video techniques and simultaneous
monitoring of psychophysiological indicesrevealed that the imitative
phenomenon is just one index of inborn sociality, one of our mostimportant
domain-general capabilities. our studies it was established 1)
that the mechanism ofthe Meltzoff-Moore effect is human imprinting
and 2) it was discovered that besides imitating, amajority of
newborn babies (2-8 hours of age) provoked the adults to interact
with them. Theinborn sociability reflected these provocations
might supply the necessary but not sufficientprerequisites for
all later social interactions with significant others, finally
resulting our socializedindividuality. The dual concept of Homo
Imitans-Homo Provocans is suggested to depict theevolutionary
foundation of the complex process of socialization-enculturation.
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Evolutionary Explanation for Cognitive Illusions
Randolph Nesse
University of Michigan,
Ann Arbor, MI 48109-0704
rnesse@umich.edu
Human inference deviates from the Bayesian norm multiple ways,
as documented by socialpsychologists over the past three decades.
These apparent cognitive flaws offer clues to the highlevel proximate
mechanisms of the mind, just as perceptual illusions highlight
otherwise hiddenperceptual mechanisms and just as diseases reveal
physiological mechanisms. The categories of evolutionary explanations
useful for Darwinian medicine also provide a useful approach toexplaining
cognitive illusions. Specifically: 1. Some apparent flaws are
actually useful ( e.g.,emotions); 2. Some flaws are disadvantages
only a modern environment (e.g., inattention to baserates?); 3.
Many flaws are actually tradeoffs between different modes of reasoning
or the costs vs.the benefits of having and maintaining a complex
decision making machinery (e.g., fundamentalattribution fallacy);
4. Some cognitive limits result because natural selection can
never start afresh(e.g., availability and salience heuristics?).
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Causation and the Tabula Rasa Mind
Tim O'Meara
Anthropology, History and Philosophy of Science
University of Melbourne
Parkville, VIC 3052, Australia
omeara%anthropology@pc.unimelb.edu.au
Abstract: The idea of an autonomous social science rests on the
250-year old "empiricist" accountof causation which
mistakenly accords causal efficacy to events rather than to physicalmechanisms.
This account appears to allow social scientists to skirt questions
of psychology andbiology by raising explanations to a supra-physical
level where human behavior is governed byautonomous societal laws.
The Empiricist account thus leads necessarily to the assumption
of atabula rasa mind. Since evolutionary psychologists reject
the tabula rasa mind, they must alsoreject the empiricist account
of causation. This paper presents an argument for rejecting theempiricist
account of causation favor of a physical/mechanical account which
evolutionary psychologists already employ intuitively. Indeed,
the success of evolutionary psychology is due asmuch to the intuitive
use of this physical/mechanical account of causation and of causal
laws as tothe use of evolutionary theory for generating hypotheses
about the mechanisms.
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Restructuring Governance Using Evolutionary Psychology
William R. Page
Center for Psychology and Social Change
An Affiliate of Harvard Medical School at The Cambridge HospitalHome
Address: Orleans, Vermont 05860 Much effort is being directed
at redesigning governance at all levels, national, state, and
local.This has been precipitated largely because social policies
have been based on assumptions abouthuman nature which are not
consistent with insights from evolutionary psychology. Thispresentation
will review these assumptions and show why they have failed. Then
it will show howevolutionary psychology is guiding restructuring
using more comprehensive and robustassumptions about human nature.
Suggestions will be offered about future research opportunitiesexpanding
the utility of evolutionary psychology.
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Male Perceptions of Female Attractiveness: The Importance of Waist-to-Hip
Ratio
Boris Palameta & Stacey Martin
Psychology Department,
St. Thomas University
Fredericton, N.B. Canada E3B SG3
e-mail: PALAMETA@STTHOMASU.CA
Human males may have been selected to evaluate potential mates
on the basis of cues thathonestly advertise health and fertility.
One such cue may be low waist-to-hip ratio (WHR). 77male university
students rated the attractiveness of female figures with WHR's
ranging from approximately 0.65 - 0.80. The figures were derived
from photographs of three volunteers fromdifferent weight categories
(normal weight, overweight, and underweight). A computer program
was used to darken the photographs and to manipulate WHR's. Six
different figures wereproduced for each volunteer model. Each
participant rated all six figures from one randomlyselected weight
category. Normal-weight and underweight figures were rated as
more attractivewhen weight was removed from the waist rather than
the hips; the reverse was true foroverweight figures. Despite
their lower WHR's, figures with enlarged hips were not rated as
moreattractive than figures with enlarged waists. The importance
of WHR as a criterion of mate choicemay vary with local conditions.
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"#
"Anthropology's Mythology": What Every Group Selectionist
Needs To Know
Craig T. Palmer, B. Eric Fredrickson, & Chris F. Tilley
Department of Anthropology
University of Colorado at Colorado Springs
Colorado Springs, CO 80933
CTPALMER@Excel.UCCS.edu
For group selection to have been a force in human evolution, ancestral
humans must have livedsocial groups which were so bounded and
enduring that they served as "vehicles" of selection
bycausing their members to have a high degree of shared fitness.
This paper argues that none of theterms asserted to be such an
entity (i.e. clans, lineages, kin groups, villages, hamlets, bands,
tribes,social organizations, populations, societies, and cultures)
fulfill this requirement because they areall either: 1) reified
abstractions, 2) groups only the sense of categories of people
instead ofgroups the sense of people gathered together, or 3)
much too fluid and fuzzy their membership.Following Murdock, we
refer to this obsession with groups as "anthropology's mythology"
andwe discuss its implications for postulated examples of group
selection human evolution.
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Status, Warriorship and Alliance the Ecuadorian Amazon
John Patton
Department of Anthropology
UCSB
Santa Barbara, CA 93106
6500patn@ucsbuxa.ucsb.edu
The relationship between warriorship and social status has long
been noted anthropologicalliterature and is currently a central
issue concerning the use of Darwinian models the explanationsof
Yanomamo violence. Despite this, empirical studies examining the
relationship between statusand warriorship are lacking. Data collected
during ten months of fieldwork an Achuar andQuichua speaking community
the Ecuadorian Amazon are examined to argue that warriorship isa
fundamental unit of status small scale societies like those which
we evolved. It is argued that abetter understanding of status
emerges when systems of status are modeled within the context
ofcoalitional psychology. Salient patterns informant judgments
of status and warriorship appearwhen coalitional membership and
bias are controlled. These coalitional differences judgmentsprovide
clues to the types of information and cognitive rules used by
informants to assess status. A model of social status this community
is presented that explains over ninety percent of thevariation
men's status.
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Homo ludens loquens: Play as a pathway to speech
Elizabeth H. Peters and Scotty Hudson
Department of Anthropology,
Florida State University
Tallahassee, Florida 32306-2023
epeters@mailer.acns.fsu.edu
From an evolutionary perspective, the costs of animal play are
easier to identify and measure thanthe benefits. To explain the
evolutionary emergence of play, it may be useful to look at the
brainchanges which accompany play behavior. repetitive interaction
with the environment, the playinganimal is selectively facilitating
neural connectivity and building brain circuitry. If it is reasonably
to suggest that the lineage leading to modern humans is characterized
by an increase epigenetically-constructed circuitry, then it may
also be reasonable to propose that this lineage ischaracterized
by an accompanying increase motivation to play and the amount
of time spentplaying. The antecedents of modern humans may have
been a hyper-play lineage with a largeamount of motor behavior
grounded play-acquired synaptic wiring. This may have provided
apre-adaptation for co-opted use of this wiring potential the
specialized motor-cognitive outputwe call speech.
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Sexual Jealousy and Mate Retention Tactics
Nicholas Pound
Department of Psychology,
McMaster University Hamilton,
Ontario, Canada, L8S 4K1
poundn@rnac.psychology.mcmaster.ca
Evolutionary psychologists consider certain human emotions to
have evolved to motivate adaptive behavior the sexual domain.
Non-evolution-minded cognitive psychologists have also argued
that dysphoric emotions signal strategic interference and motivate
adaptive responses. These perspectives are ripe for conceptual
integration.The reliability of a mate retention tactics questionnaire
was assessed and, addition, an associationbetween sexual jealousy
and the performance of particular tactics was demonstrated that
isconsistent with an adaptionist perspective.
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Cosmetic manipulation of menstrual signals as a protosymbolic
strategy
C Power
Department of Anthropology,
University College London
Gower St., London WCIE 6BT
e-mail ucsaccp@ucl.ac.uk
Once menstruation had become the only indicator of imminent fertility
in the hominid lineage,males had an interest in detecting menstruation
in the local female population. Females could haveenhanced fitness
by competitively manipulating menstrual signals to attract high
quality mates.Menstruation functioned to obtain greater mating
effort from males, but not reliable parentaleffort. A male who
targeted menstrual females was liable to desert a current partner
once she was pregnant/lactating. With the exponential increase
of brain size characteristic of archaic HomoSapiens, the level
of investment obtained from males became a limiting factor on
female fitness.Females could extract extra provisioning from males
by displaying copycat' signals around anylocal menstrual female,
thwarting male attempts to target the menstruant. A female kin-basedcoalitionary
strategy of cosmetic display around a menstruating relative would
effectively advertise her fertility to attract male investment.
This strategy forms a preadaption to ritual and symbolic behavior.
The model provides a parsimonious explanation for the archaeological
recordof pigment use among early anatomically modern humans.
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Pedophilia and the Design of Male Sexual Age and Gender Preferences
Vernon L. Quinsey & Martin L. Lalumiere
Queen's University,
Kingston, Ontario, K7L 3N6
Quinsey@Pavlov.Psyc.QueensU.Ca
Whether measured by penile plethysmography, covertly measured
viewing time, or attractivenessratings, heterosexual males prefer
average weight young women with prototypical female hip towaist
ratios. There is also strong inter-rater agreement on female attractiveness,
even within thepreferred sex and age category. Computer averaged
composite faces are preferred to the faces ofindividuals. This
exquisite tuning of male sexual interest to signs of reproductive
capability, suchas gender, youthfulness, body shape, and (perhaps)
absence of genetic anomalies, stronglysuggests that it is an adaptation.
It is, therefore, puzzling that some males prefer prepubertalchildren
as sexual "partners." This phenomenon may be because
the male sexual preferencesystem is designed with discrete modules
tuned to particular features of the environment, eachfeature being
relevant to a particular ancestral reproductive problem in mate
selection. If thesemodules can malfunction independently from
one another, one can derive the observed sexual ageand gender
preferences of pedophiles.
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The Evolution of Human Ultra-sociability
Peter J. Richerson,
Division of Environmental Studies,
UC Davis
Robert Boyd,
Department of Anthropology,
UC Los Angeles
Most contemporary human societies are very large and exhibit a
degree of cooperation,coordination, and division of social labor
that rivals and even exceeds the other pinnacles of socialevolution,
such as the eusocial insects. Even simple human societies show
elements of complexityabsent in other primates. There is as yet
no generally accepted evolutionary explanation forhuman social
complexity. Kinship, reciprocity, and dominance are clearly important
componentsof human social institutions, but appear insufficient
in themselves to explain the size and degree ofstructure of human
societies. Group selection on genes probably cannot explain human
ultra-sociality because human mating systems are fairly open.
We propose that culturale volutionary processes are ultimately
responsible for human ultra-sociability. Group selection of cultural
variation and the use of culture to erect symbolic barriers between
groups can account for ethnocentrically limited altruism that
underpins human social organization. Such cultural evolution plausibly
drove a coevolutionary response, adapting human psychology to
a cultural environment characterized by cooperation between cultural
in-group members with neutrality to hostility to out-group members.
Theoretical investigations suggest the limitation of mechanisms
such as indirect reciprocity and archaeology support elements
of the argument. Psychological investigations indicate social
"instincts" adapted to the group selection and boundary
marking pressures from the cultural side. By the late Pleistocene
human populations had apparently evolved a social "grammar"
sufficient to support the rapid emergence of complex societies
in the Holocene, albeit fragile, conflict-ridden ones.
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A BIOLOGICAL BASIS FOR EXPECTED AND NON-EXPECTED UTILITY
Arthur J. Robson
Department of Economics,
University of Western Ontario,
London, Ontario,CANADA N6A SC2.
E-mail: ROBSON2@SSCL.UWO.CA
A biological model is developed here to determine the fittest
attitude to risk. With a fixedenvironment, the type maximizing
expected offspring is selected. This yields the expected utilitytheorem
when translated into a criterion for evaluating gambles over commodities.
With a random environment, however, the type selected is strictly
less averse to idiosyncratic risk than to riskwhich is correlated
across all individuals. The implied criterion for choice over
gambles does notsatisfy the expected utility theorem and may induce
choice of a gamble which is first-orderstochastically dominated.
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Deception, Self Deception and Myth: Settlement of Complex Environmental
Disputes
William H. Rodgers, Jr.
University of Washington
School of Law
Seattle, WA 98105
whr@u.washington.edu
This paper will draw on experiences in ethology, psychology, and
the literature of deception andself-deception. It will apply ideas
from these fields of evolutionary biology to complex contemporary
disputes, including clean up of the Hudson River, the disposal
of DDT into Santa Monica Bay, and proposals to shoot "Hershel",
the sea lion who is feasting upon endangered steelhead at the
Ballard Locks in Seattle.
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.
Disorder Profiling: Anorexia Nervosa and Bulimia Nervosa
Linda B. Roswell & Sabura Woods
Department of Psychology,
Virginia Commonwealth University
806 West Franklin Street,
Richmond, VA 23284-2018
E-mail: psy31br@cabell.vcu.edu
A procedure for profiling psychological disorders from an evolutionary
perspective was recentlyintroduced (Bailey and Roswell, 1995).
In that article, Anorexia Nervosa was profiled in somedetail.
Our poster will present comparative profiles for Anorexia Nervosa
and Bulimia Nervosa.Procedures for disorder profiling in general,
and specific profiles for Anorexia and Bulimia will be discussed.
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Between and Within Sex Variation: Are the Causes Alike?
David C. Rowe & Alexander T. Vazsonyi
FCR 210 University of Arizona,
Tucson, AZ 85721
DCRO91@AG.ARIZONA.EDU
Traits such as mating promiscuity, impulsivity, and crime show
tremendous sexual dimorphism.However, tremendous variation exists
in these same traits within each sex (e.g., just 6% of malesaccount
for the majority of all crimes). This study examines the traits
of mating effort, impulsivity,and delinquency using structural
equation models. Males and females differ on these traits byabout
one SD. Using siblings, a structural equation model is fitted
to the individual differencesthat is the same across sex. A genetic
and an environmental factor accounted trait variation inboth sexes
equally. Displacements in the genetic and the nonshared environmental
factor-meanscould account for the mean sex differences. The question
posed in this abstract's title is thusanswered in the affirmative.
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Closeness, Identity, and Social Relationships
Catherine Salmon
McMaster University,
Hamilton, Ontario L8S 4K1
g8815958@mcmaster.ca
Traditional approaches to family and social relations have often
emphasized the role of thegeneration gap' and cultural norms in
structuring social and personal relationships. This viewseems
inadequate. This study explored factors related to closeness to
kin and other socialcontacts and the relative importance of family
names and roles, as well as the relevance of birthorder to both
these issues. A family role (such as daughter or brother) was
more relevant towomen's sense of self-identity than men's, while
last names were more relevant to men's self-identity than to women's.
Birth order influenced this relevance in men but not in women.
Birthorder also impacted on closeness to kin vs. non-kin.
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MATE SELECTION THEORY: INVESTIGATING WOMEN'S CHOICES OF DONORS
ATA CANADIAN SPERM BANK
Joanna E. Scheib
Department of Psychology,
McMaster University
Hamilton, Ontario, Canada
scheib@mcmaster.ca
Artificial insemination by sperm donor is the most common type
of assisted reproductivetechnology used to achieve pregnancy in
healthy women. A sperm donor is usually chosen on thebasis of
his resemblance to the woman's marital partner. An increasing
proportion of these womenare single however, and the basis of
their choices of sperm donors (if given choice!) has yet to beestablished.
Mate selection theory and results from an experimental study in
which women chosesperm donors in an hypothetical scenario were
used to investigate the predictors of clients'choices of donors
at a Canadian sperm bank.
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SCHIZOPHRENIA AND NONVERBAL SOCIAL BEHAVIOR IN PAPUA NEW GUINEA
Karen L. Schmidt* and John S. Allen***
Dep't. of Anthropology,
U.C. Berkeley,
Berkeley, CA 94720,
schmidt@qal.berkeley.edu**
Dep't. of Anthropology,
University of Auckland,
Auckland, New Zealand,
jsa@antnov1.ac.nz
The goals of this study are to describe the nonverbal social behavior
of schizophrenics in PapuaNew Guinea and to consider the concept
of a species-specific psychological adaptation fornonverbal social
interaction. Inappropriate or unusual patterns of verbal and nonverbalcommunication
are important in the diagnosis of schizophrenia The judgement
that behavior isunacceptable rests largely on the clinical experience
and intuition of the psychiatrist. Cross-cultural identification
of schizophrenia, especially of nonverbal behavior, also requires
thatcultural differences be distinguished from pathological differences.
It is possible that at least partof the cross-cultural recognition
of schizophrenia has to do with species-specific to detect andmake
use of universal interaction patterns.In this study, interviews
with patient and matched control subjects were videotaped and
laterevaluated (without sound) by research assistants who were
unaware of the subjects' clinical status.Assistants gave both
qualitative impressions and quantitative assessments of nonverbal
behavior.Results showed that schizophrenic subjects differed from
controls, having a greater range ofnonverbal expression over the
course of the interview. Relationships between assistants'judgements
of nonverbal expression and the nonverbal expressions were also
investigated.
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Is syntax simply an emergent characteristic of the evolution of
semantic complexity?
P. Thomas Schoenemann
Department of Anthropology,
University of California, Berkeley,
94720
E-mail: schoenem@qal.berkeley.edu
Many consider the rules of language to be the features which most
clearly distinguish it fromcommunication systems of other species.
A number of linguists have taken the position thatuniversal grammar
is likely a unique human adaptation showing no evolutionary continuities
withclosely related species. How then can we explain the evolution
of universal grammar? We mustfirst ask what the features of universal
grammar actually look like. Recent summaries areremarkable in
the very general nature of the features proposed. While syntactical
features in anygiven language are often quite complex, it appears
that these features vary so much betweenlanguages that the truly
universal (i.e., innate) aspects of grammar are not complex. In
fact, muchof universal grammar may instead be descriptions of
our richly complex semantic world, notdescriptions of rules per
se. The question addressed in this talk will be the extent to
whichdifferent proposed features of universal grammar might more
properly be thought of as reflectinguniversal semantics. The specific
rules used by languages would then be simply emergentcharacteristics
of the explosion of semantic complexity seen in hominid evolution.
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Bereavement in Monozygotic and Dizygotic Twins: An Evolutionary
Perspective
Nancy L. Segal & Shelley A. Blozis***
California State University,
Department of Psychology,
Fullerton, CA 92634**
University of Minnesota,
Department of Psychology,
Minneapolis, MN 55455
Interest in individual differences in bereavement response has
increased in recent years. As part ofthe California State University
Twin Loss Study, a comprehensive Twin Loss Survey wascompleted
by 188 monozygotic (MZ) and 87 dizygotic (DZ) twins who lost their
co-twins. Griefintensity ratings were higher for MZ than DZ twins
(p~ .01), and higher for females than for males(p~ .01). Grief
intensity ratings provided for deceased twins exceeded those for
deceased parents,grandparents, non-twin siblings, aunts, uncles,
and friends (p< .001), and were comparable to those for deceased
spouses. Twins' scores on all Grief Experience Inventory (GEI)
scales significantly exceeded those of 102 recently bereaved non-twin
individuals; scores of recentlybereaved twins exceeded those of
bereaved children and spouses, and were slightly higher thanthose
of bereaved parents. GEI scale scores of MZ twins generally exceeded
those of DZ twins,with differences reaching significance on five
of nine scales. These findings and models depictingrelationships
among genetic relatedness, social closeness, grief intensity,
physical symptoms, sex,age at loss and coping were examined with
reference to evolutionary and psychobiologicalperspectives.
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YOUNG CHILD GROWTH AS A PROXY FOR FITNESS DIFFERENTIALS AMONG
POLYGYNOUSDATOGA
Daniel W. Sellen,
Department of Anthropology,
Program in International Nutrition and GraduateGroup in Ecology,
University of California at Davis,
Davis, CA 95616
I examined offspring growth performance as a component of lifetime
reproductive success amonga sample of mothers (n=81) from pastoral
Datoga households in Tanzania. The outcomevariables (anthropometric
scores of individuals), were chosen because they are strong predictorsof
morbidity and mortality in traditional and developing populations.
Controlling for a host ofsocio-ecological factors found to affect
child growth, and therefore child survival, it was foundthat both
monogamous and primary polygynous wives had children whose growth
performancewas markedly better than that of the children of other
women. This result was consistent withtwo non-mutually exclusive
models of co-wife differentials, that of labor control and that
ofresource-sharing. Maternal interview data suggested that, among
African pastoralists: (I) anymarital choice based on fitness maximization
must entail assessment of a multitude of factorsaffecting offspring
survival (ii) child feeding and care practices are important mediating
factors inproducing fitness differentials among mothers of differing
marital status. It also demonstrated thewider potential of using
growth as a proxy for fitness in evolutionary ecological anthropology.
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The Relationship of Psychological Health and Differential Parental
Investment in Humans
Richard M. Seneniuk & Charles B. Crawford
Dept. of Psychology,
Simon Fraser University
Burnaby, B.C. V5A lS6
e-mail:CharlesCrawford@sfu.ca
The Trivers-Willard differential investment model predicting good
parental condition beingassociated with investment toward sons
and poor condition toward daughters has received onlymixed support
in humans. We suspected that psychological health may be a better
measure ofoverall parental condition and that good mental health
would be related with a male bias andpoorer health with a female
bias. Study results showed that health was associated with measuresof
preferences for sex of offspring, but in an unhypothesized manner.
Generally, highest levels ofpsychological health in undergraduate
subjects was associated with no bias, moderate levels witha same-sex
bias, while lowest levels of psychological health predicted an
opposite sex bias. Explanations for these results within an adaptationist
framework are discussed.
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Cues to Infidelity
Todd K. Shackelford* and David M. Buss
University of Michigan,
Dept. Of Psychology,
Ann Arbor, MI 48109-1109*
e-mail: tkshack@t.imap.itd.umich.edu
This series of studies sought to identify cues that signal a partner's
sexual infidelity andromantic-emotional infidelity. In Study 1,
204 subjects identified the events that might lead themto suspect
that their long-term partner was sexually or romantically unfaithful.
We identified 170cues to a partner's infidelity. In Study 2, 116
subjects evaluated the 170 acts on how diagnostic(act diagnosticity)
each act was of (a) sexual infidelity and (b) romantic infidelity.
In Study 3, 114subjects gauged the same 170 acts on the likelihood
(act likelihood) that each act would occurgiven a partner's (a)
sexual or (b) romantic infidelity. We identify the 50 acts most
diagnostic ofromantic infidelity, and the 50 acts most diagnostic
of sexual infidelity, collapsed across sex oftarget and sex of
rater. In general, men and women perceived similar diagnosticities
andlikelihoods for a given act, collapsed across sex of target.
Several sex of target effects in judgingthe likelihood of sexual
infidelity were identified. In all cases, men were judged more
likely tohave been sexually unfaithful, collapsed across sex of
rater. Several sex of rater by sex of targetinteractions were
observed for judgments of act diagnosticity with regard to sexual
infidelity. For each act, men judged sexual infidelity more likely
if the target was a woman. Women, in contrast,judged sexual infidelity
more likely if the target was a man. A similar pattern held for
the sex ofrater by sex of target interactions in judging likelihood
of an act given that an infidelity has occurred. We present those
acts that, collapsed across sex of rater and sex of target, aredifferentially
diagnostic of sexual and romantic infidelity.
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EVOLUTIONARY ISSUE RAISED BY SELF-SACRIFICIAL MILITARY HEROISM
Jonathan Shay, M.D., Ph.D.
Department of Veterans Affairs
Outpatient Clinic and Tufts Medical School
Department of Psychiatry,
Boston
[Mail: 11 Miller St.,
Somerville, MA 02143
E-mail: jshay@world.std.com]
Non-kin military comrades who have previously fought side-by-side
endanger themselves to protect each other in a wide variety of
cultural/historical war settings. The prodigious death rate among
such heroes raises the question of how this behavior could have
evolved. In 1930, R.A.Fisher claimed that "the sacrifice
of individual lives...is a minor consideration compared with the
enormous advantage conferred by the prestige of the hero upon
all his kinsmen". Homer's epics paint a contrary picture.
I appeal for empirical research into the reproductive success
of the kin of dead war heros.
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FILLING TWO VOIDS WITH ONE CLONE: TEACHING FRESHMAN EVOLUTION
AND BEHAVIOR
Thomas L. Shellberg
Henry Ford Community College,
Dearborn, MI
Despite the exponential uptake of the evolution revolution since
Hamilton and the consequentrenaissance in the study of Pope's
"Proper study of man", few college students learn even
the mostbasic principles of modern selection theory or its applications
to understanding human behavior.The behavior education of most
students is still largely limited to pre-Lorenzian, pre-Hamiltonian,even
pre-Darwinian perspectives on human nature. Traditional psychology
and sociology coursesare offered everywhere but comparable introductory
courses in behavioral biology are virtuallynonexistent. It's a
rare college grad. who knows what natural selection has to do
with mate choiceor homicide statistics, or why philosophy majors
should study ethology and evolutionarypsychology. Education majors
learn little about the biology of learning and pre-law and politicalscience
majors aren't learning about testosterone or serotonin or the
biology of motivation or theevolution of political behaviors.
We have not provided intro. courses to fill the evolution andbehavioral
biology educational voids at the freshman/sophomore levels in
our colleges. It's timewe did. For 15 years I've been teaching
a big (150 students per semester), no-prerequisite, 4 credit science
course in Evolution & Behavior at Henry Ford. Student response
on anonymousevaluations has been very enthusiastic. Virtually
all students from art to pre-med. majors say thissubject matter
should be required for most all college students. My presentation
will outline thecourse and offer suggestions for "cloning"
the basic procedures and essential memes to fill theseevolution
and behavioral biology educational voids.
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THE CHAOS OF HUMAN BEHAVIOR: Chaos, Complexity, and the Self-Organization
of Human Behavior
Michael Shermer,
Occidental College
2761 N. Marengo Ave.,
Altadena, CA 91001
Ph: 818/794-3119; Fax: 818/794-1301
E-mail: skepticmag@aol.com
The analysis of physical and biological systems through models
and mathematics of chaoticbehavior and nonlinear dynamics rose
to prominence in the 1980s. Many authors, most notably Ilya Prigogine,
made glancing references to applications of this new paradigm
to the social andhistorical sciences, but little fruit was harvested
until this decade. Physiologists studying irregular heart rhythms,
psychologists examining brain activity, biologists graphing population
trends,economists tracking stock price movements, military strategists
assessing the outbreak of wars,and sociologists modeling the rise
of cities, found nonlinear dynamics refreshingly stimulating inreevaluating
(and often restructuring) old theories, and creating new ones.
More sophisticatedmodels of human history, society, and behavior
is an inevitable extension of this trend, and thisauthor will
use such concepts as complexity, simplexity, self-organization,
antichaos, andfeedback mechanisms to show that modern social movements
change in a Parallel fashion ashistorical ones, and that there
may be "strange attractors" in human behavior that determine
social outcomes.
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Sex Hormone Levels and Cognitive Abilities in Males
I. Silverman, D. Kastuk, J. Choi, & K. Phillips,
York University
E. Hampson,
University of Western Ontario
E-Mail: ISILV@VM1.YORKU.CA
Testosterone (T) levels were measured by salivary assays in 59
males at times of the day when Twas expected to be highest and
lowest. Estrogen (E) levels for each session were also assessed.Relationships
were evaluated between hormone levels and performance on a three
dimensionalmental rotations test which customarily favors males
and two female-biased cognitive tests,Anagrams and Digit Symbols.
The data showed a significant positive relationship for T level
anda significant negative relationship for E level with mental
rotations. There was no coherent pattern of results for the other
tests. Findings are discussed both in terms of prior reported,conflicting
data and support given to evolutionary based theories of spatial
sex differences.
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Evolving Virtual Creatures (a video animated simulation).
Karl Sims
(Presented by proxy by Nicholas Gessler)
Thinking Machines Corporation,
245 First Street
Cambridge, Massachusetts 02142
e-mail: sims@media.mit.edu
This video shows the operation of a system for the evolution and
co-evolution of virtual creatures that compete in physically simulated
three-dimensional worlds. Pairs of individuals enterone-on-one
contests in which they contend to gain control of a common resource.
The winners receive higher relative fitness scores allowing them
to survive and reproduce. Realistic dynamicssimulation including
gravity, collisions, and friction, restricts the actions to physically
plausible behaviors.The morphology of these creatures and the
neural systems for controlling their muscle forces are both genetically
determined, and the morphology and behavior can adapt to each
other as theyevolve simultaneously. The genotypes are structured
as directed graphs of nodes and connections,and they can efficiently
but flexibly describe instructions for the development of creatures'
bodiesand control systems with repeating or recursive components.
When simulated evolutions areperformed with populations of competing
creatures, interesting and diverse strategies andcounter-strategies
emerge.(Note: This is a truly remarkable video which is suggestive
of the possibility of evolving modelsof the relative adaptivities
of various hominid behaviors, physiologies, and morphologies.--Nicholas
Gessler.)
Anorexia and bulimia as two different strategies for
reproduction suppression Devendra Singh Previous adaptationistic
explanations of eating disorders have proposed body weight regulation
asa mechanism to suppress reproduction. However, women suffering
from bulimia have normalbody weight and have a distinctly different
behavioral and neuroendocrinological profile than women suffering
from anorexia. I will present evidence showing, first, that anorexia
and bulimiaare indeed distinct disorders maintained by some overlapping
but mostly different biobehavioralmechanisms. Second, I will present
evidence suggesting that anorectics use a developmental("opting
out") strategy whereas bulimics use a concurrent ("bettering")
strategy for reproductivesuppression
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Men's preference for romantic relationships: pretty faces or beautiful
bodies?
Devendra Singh and Suwardi Luis
To evaluate the role of facial attractiveness and body shape (as
defined by the waist-to-hip ratio,WHR) on preference for short-
and long-term relationships, facial photographs differing in degreeof
attractiveness were paired with photographs of female bodies with
differing WHR. Ratings ofoverall physical attractiveness were
affected by both facial attractiveness and WHR, butdesirability
for both types of romantic relationships were solely determined
by WHR.
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Attachment Theory and the Involuntary Subordinate Strategy
Leon Sloman,
MD250 College Street
Toronto, Ontario, MST 1R8
Sloman L@Clarke-inst.On.CA
Cathron Hilburn-Cobb, Ph.D.
Hincks Treatment Centre
440 Jarvis Street
Toronto, Ontario, M4Y 2H4
An outline will be presented of Social Competition Theory which
encompasses the InvoluntarySubordinate Strategy (ISS). Two parental
styles are the Authoritative and Authoritarian. We willexamine
the interaction between the ISS, parental style variables and
other ethological behaviouralsystems like Attachment, Caregiving,
and Affiliation. Two types of insecure attachment areAvoidant
attachment and Insecure attachment while a secure attachment is
Balanced. Healthy development, which includes the appropriate
handling of agonistic encounters, requires anappropriate balance
between self-regulatory strategies for managing arousal and a
reliance onregulation by an attachment figure. The interaction
between these variables provides acomprehensive perspective for
understanding the factors that contribute to depression and other
forms of psychopathology.
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Birth Order and Political Behavior: A Sex Related Effect?
Albert Somit, Steven A. Peterson, Alan Arwine
7231 San Benito
Alfred University
Southern Illinois University
Carlsbad,, CA 92009
Alfred, NY 14802
Carbondale, lL 62901
fpeterson@bigvax.alfred.edu gr8123@siucvmb.edu
The birth order literature argues that first borns are more achievement
oriented. As such, they ought to be more successful in politics
(including becoming eminent). However, our data on aseries of
positions (US Presidents, British Prime Ministers, US Supreme
Court justices, US Senators and Representatives make this conclusion
suspect.However, most of our data are on males. We have recently
begun studying the relationshipbetween birth order and politics
among female leaders. Thus far, we have data on women mayors,women
state legislators, and women judges. What we find is that birth
order DOES make adifference with women.Thus, the purpose of this
paper would be to summarize the intriguing sex-related effects
and thento speculate as to why these differences might exist.
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Selective fosterage, impulse to teach, and gene/culture interaction
Arthur M. Squires
Virginia Polytechnic Institute & State University
P.O. Box 10098,
Blacksburg, VA 24062
E-Mail: VERASQU@VTVMI.CC.VT.EDU
A teacher or a person wielding power can earn an increase in a
targeted inclusive fitness(self-chosen, targeted to particular
genes) through selective fosterage of a youth in whom thefosterer
senses cryptokinship (heritable qualities expressed in both fosterer
and fostered). Via theevolutionarily ancient drive for status
and a newer impulse to teach, fosteral selection maintainsnew
specialist subpopulations as they arise: each with its hierarchy;
each with committed teachers;each, for continuation, requiring
heritability of a genetically complex behavioral polymorphismfitting
it to occupy a certain socioeconomic niche; many, through selective
fosterage, drawingrecruits from a largely unspecialized majority;
many, reproductively semi-isolated; many,selectively fostering
docility or indoctrinability. Fosteral selection remains an active
agent: for anindividual, it can expand opportunity for fitness
accumulation beyond loss of occasion or capacityfor reproduction;
for the powerful, it may provide a primary reward for whatever
struggle orpoliticking has been invested into achieving high place.A
notional australopithecine social order (comporting with fossil,
archeological, andprimatological evidence) suggests fosteral selection's
likely importance early in our line's story.
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Traditions are not "r"
Lyle Steadman
Arizona State University
Department of Anthropology,
Tempe, AZ 85287
The success of a K-strategy cannot be assessed by counting numbers
of offspring, associobiologists currently do. K-strategy not only
involves putting more parental resources intofewer offspring,
but having offspring (and more distant descendants) who do the
same. The r-strategy is always POTENTIALLY more successful than
K-, but in competition with K-individuals -- those who receive
more parental resources -- r-strategies can lose. Humans,distinguished
from all other species by an enormous amount of ancestrally encouraged
traditions,exhibit a uniquely extreme K-strategy. Humans not only
reduce their reproduction to teach theiroffspring traditions,
they encourage their offspring to do the same AND to pass on thisencouragement
to the offspring's descendants. Thus, the success of traditions
cannot bemeasured by counting offspring.
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Literature and Evolution: A Functional Approach
Francis F. Steen
Department of English,
UCSB,
CA 93106
steen@humanitas.ucsb.edu
The performance of fictional narratives is among the activities
of Universal People, and a likelydesign feature. The ability to
be emotionally and intellectually engaged by verbal and non-verbal
stimuli that are framed as fictional depends in part on autonoetic
awareness of episodic memory.This may be proposed to function
by eliciting information from cue-based cognitive modules bymeans
of an internal mimicry of sensory stimuli, coordinating this diverse
information intocoherently flowing scenarios that can be evaluated,
and then committing elements of these tomemory to serve as behavioral
scripts. Such scripts may be most effectively communicatedthrough
fictional narratives that access the relevant resources in the
listener, functioning likesearch engines in a virtual reality
machine. When individuals evaluate a fictional narrative, wewould
thus expect a proximal concern with the richness of simulated
experience and a distalconcern with the realistically possible,
knowledge, and truth.
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Effects of Photoperiod on Ovulation in the Female Meadow Vole
Susan Stewart, Kris Krajnak & Theresa Lee
Dept. of Psychology,
Neuroscience Bldg.
University of Michigan,
Ann Arbor, MI 48104-1687
E-mail: Susan.F.Stewart@um.cc.umich.edu
Meadow voles (Microtus pennsylvanicus) have evolved interesting
adaptations to cope withtemperate environments. Though seasonal
breeders, mating occurs in winter months, however,fertility is
decreased. Laboratory studies indicate that females housed in
winter-like photoperiodshave lower fertility rates than animals
housed in summer-like photoperiods. One possibility forthis decreased
fertility is that the females' ovaries are not producing Graffian
follicles necessaryfor ovulation. This experiment examined the
effects of a single luteinizing hormone (LH) injectionin females
housed in either a long daylength (LD) or short daylength (SD)
photoperiod. All LDand SD animals ovulated when given a LH injection
at the onset of mating. All LD but only 25%of SD females ovulated
when paired with a male but mating never occurred. When only a
LHinjection was given, 75% of LD and 22% of SD females ovulated.
This suggests that decreased fertility in mated animals is not
an effect of photoperiod directly on ovarian function. SD is likelydepressing
the hypothalamic-pituitary system in females, but pairing with
a male can alter thisresponse in some females.
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Neurological models of facial expression recognition
Valerie E. Stone
Center for Neuroscience,
University of California,
Davisszstone@rocky.ucdavis.edu
An animal that is able to anticipate the behavior of other members
of its species has a significantadaptive advantage. Facial expressions
of certain emotions correspond to specific patterns ofautonomic
nervous system activity, which prepare an individual for different
actions, e.g. fight orflight. Thus, because they may give reliable
and discriminant information about something that isusually private,
i.e., another person's physiology, facial expressions of emotion
are extremelyimportant in enabling us to predict another person's
probable actions (Stone et al., 1995).The ability to perceive
and discriminate these social signals is an adaptively important
cognitiveability, one for which we might expect to find specialized
neurological mechanisms. However,empirical evidence does not strongly
support the conclusion that cortical processes involved inperception
and categorization of facial expressions differ from cortical
processes for more generalpattern recognition. Content-specific
mechanisms for responding to others' facial expressions mayoccur
at the level of the limbic system. I will discuss the relative
roles of the right and leftcerebral hemispheres and the amygdala
in the recognition of emotional facial expressions.(Supported
by NINDS Grants P01 NS17778-12 and PHS NS31443-01.)
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Models of intraspecific competition: Strategies for social climbing
Valerie E. Stone and Clifton Kussmaul
Center for Neuroscience,
University of California,
Davisszstone@rocky.ucdavis.edu, kussmaul@dunkel.ucdavis.edu
Competition for rank and resources is a central domain of human
and animal behavior. Weexplored adaptive competition strategies
under different environmental conditions through a seriesof mathematical
models of competition between a set of ranked critters belonging
to a singlespecies. The models explore which competition strategies
(rules for deciding who to competewith) would be adaptive. We
present two models for the payoff from a particular competition:
1)fixed payoff regardless of the competitors' ranks; 2) payoff
proportional to the loser's rank. In thefirst model, we found
that the only competition strategy with a net positive payoff
would be for acritter to attack when it would be more likely to
win than lose. In the second model, there was an additional strategy
in which it would be adaptive to attack even if the attacker was
more likely tolose than win, because the attacker would not lose
much if it lost, but would gain a relatively large amount if it
won. We expect this strategy to be used primarily by critters
of low rank. We discussthe relevance of these models to competition
in real social and ecological situations: animalscompeting for
food items or territory, and humans competing for status and economic
resources.(Supported by NINDS Grant P01 NS 1777
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Menstruation and the Comparative Method
Beverly I. Strassmann
Dept. of Anthropology,
University of Michigan,
A2, MI 48109
E-mail: BIS@umich.edu
Based on data in Profet (1993) and Hrdy and Whitten, menstruation
in primates can be classifiedaccording to its copiousness: absent/covert,
slight, or overt. In previous analyses, I used Fisher'sexact test
to determine whether the copiousness of menstruation in extant
primate generacorrelates with taxonomic status, female promiscuity,
body size, litter mass, and other pertinentvariables. A limitation
of these analyses is that different genera did not arise independently
ofeach other. In recent analyses, I improved upon these methods
by using a phylogenetic approach.In particular, I used Maddison's
Concentrated Changes Test to determine whether phylogeneticchanges
in the copiousness of menstruation were more or less concentrated
in the presence ofother characters. The results confirm my previous
analyses with one exception: the copiousness ofmenstruation appears
to be unrelated to female body mass. I discuss the implications
of theseresults for understanding the evolution of menstruation.
Further, I conclude that this studyillustrates the importance
of taking phylogeny into consideration when testing for the correlatedevolution
of different characters (Harvey and Purvis, 1991; Harvey and Pagel,
1991).
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Testing tor Universality: Reasoning Adaptations Among the Achuar
of Amazonia
Larry Sugiyama*, John Tooby, & Leda Cosmides
Center for Evolutionary Psychology,
University of California, Santa Barbara,
CA 93106
tooby@alishaw.ucsb.edu
Experiments conducted in North America, Europe, and Hong Kong
have produced evidence forthe existence of cognitive mechanisms
that are specialized for reasoning about social exchange,threat,
and hazardous situations--adaptive problems that our hunter-gatherer
ancestors wouldhave faced on a day-to-day basis. If these specialized
reasoning circuits are in fact adaptations --i.e., if they are
functional components of the evolved architecture of the human
mind -- then theyshould be universal. To test this prediction,
we adapted these reasoning experiments fornonliterature subjects
and administered them to members of the Achuar, a tribal people
living inthe Ecuadorian rainforest.
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Storyteller Bias as a Fitness-Enhancing Strategy
Michelle Scalise Sugiyama
English Department,
University of California,
Santa Barbara
Stories are, in large part, representations of the human social
environment. These representationscan be used to influence the
behavior of others (consider, e.g., rumor, propaganda, publicrelations).
Storytelling can thus be seen as a transaction in which the benefit
to the listener isinformation about his/her environment, and the
benefit to the storyteller is the elicitation ofbehavior from
the listener that serves the storyteller's interests. Not all
storytellers have the sameinterests, however, because no two individuals
have exactly the same fitness interests. Therefore,we would expect
different storytellers to have different narrative perspectives
and priorities due todifferences in sex, age, social status, marital
status, etc. Tellingly, the folklore record shows thatdifferent
storytellers within the same cultural group tell the same story
differently. Furthermore,the ethnographic record provides examples
of myth-telling used as a means of politicalmanipulation. This
correspondence between differences in fitness interests and differences
innarrative perspective suggests that storytelling is a means
of promoting individual fitness interestsby manipulating other
individuals' representations of their social environment.
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Human mate selection: When big and brawny isn't always better
M.K. Surbey & B. Nagata
Mount Allison University,
New Brunswick, Canada
MSURBEY@MTA.CA
While human males tend to focus on attractiveness and physical
cues indicative of fecundity,females should to a greater extent
trade off personality attributes and male physical characteristicswhen
choosing partners. Sixty-six male and 63 female undergraduates
rated twelve drawings ofthe opposite sex on good looks, attractiveness,
and sexiness. Figures of males and females varied according to
weight (under-, normal, and overweight) while female figures (from
Singh, 1993)also varied in waist-to-hip ratio (WHR) and male figures
varied on the body dimension ofshoulder-to-hip (SHR). Consistent
with the results of Singh (1993), males rated figures with low
WHRs of average or low weight consistently higher on the three
measures of physical appeal. Ingeneral, female participants rated
the male figures with SHRs between 1.3-1.4 and of average weight
most highly. Participants were also asked to indicate their willingness
to date individuals depicted in a subset of the figures and the
personality characteristics such individuals must possessin order
to increase the participant's willingness to date them. Compatible
with the notion thatmale mate selection criteria involve physical
traits more so than personality attributes, resultsrevealed that
males more often than females left blanks rather than indicate
which personality characteristics would increase their willingness
to date the individual depicted in the figure.Furthermore, consistent
sex differences emerged regarding the types of attributes which
would increase a participant's willingness to date one of the
individuals represented in the figures.
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HUMAN EMOTIONAL ATTACHMENT TO LAND
Barty Thompson
Department of Anthropology,
University of California, Santa Barbara
6500bat@ucsbuxa.ucsb.edu
Attachments to land are hypothesized to be an adaptation, designed
to keep humans on familiarlands. Such an attachment would provide
benefits in foraging, avoiding dangers, and in cognitivecapacities.
This phenomena displays all the usual features that one would
look for in anadaptation: universality, functionality, and complexity.
Other potential explanations such asresource defense, or attachment
to associated humans do not adequately explain all the featuresexhibited
in land attachments. The existence of land attachments as a psychological
adaptationwould indicate that humans have spent a considerable
amount of their time as a more sedentaryspecies that ranged within
a familiar area, rather then as a consummate wanderer. It also
hasimplications for how humans develop psychologically in the
modern world, where the opportunityto form land attachments appears
to be decreasing.
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The Eternal Triangle and the Moral Missing Link
Lionel Tiger
State University of New Jersey
Rutgers, Douglass
CollegeDepartment of Anthropology
P.O. Box 270
New Brunswick, NJ 08903-0270
Humans evolved moral skills and enthusiasms in small-scale hunting-gathering
societies. Themove to agriculture and pastoralism appears to have
been sufficiently confounding as to lead tothe development of
the principal moral/religious systems which were products of agric/pastoralsocial
structures: "The Lord is my shepard". These remain central
to an effort at social control ofmodern communities. However,
the industrial system has produced no indigenous ethic of itsown.
The lack of fit between "is" and "ought" remains
a source of chronic and actually profoundtension.
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SEXUAL ACCESS TO FEMALES AS A MOTIVATION FOR JOINING GANGS
Christopher F. Tilley and Craig T. Palmer
Department of Anthropology,
University of Colorado at Colorado Springs
Colorado Springs, CO 80933.
E-mail: CFTILLEY@UCCS.edu
Evidence that gang membership increases sexual access to females
comes from an STD study thatfound male gang members to have significantly
higher average number of sexual partners thannon-gang males. Age
and sex compositions of gangs fit predictions from evolutionary
psychologyconcerning the human female's preference for males exhibiting
signs of status, and the humanmale's desire for a variety of sexual
partners. Although the current phenomenon of gangs in America
is influenced by unique socio-economic conditions, a full understanding
of gangs requiresan appreciation of the similarities between gangs
and other activities of young males that can beseen as attempts
to gain sexual access to females. This approach also suggests
possible means ofdecreasing gangs by providing less socially destructive
alternatives for young males.
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The Evolution of Memory, Modularity, and Information Integrity
John Tooby* & Leda Cosmides
Center for Evolutionary Psychology,
University of California, Santa Barbara,
CA 93106
Virtually all psychological mechanisms whose subsequent operation
changes in an organized waybased on input can be said to manifest
memory, and so the study of memory systems is central tomapping
the evolved architecture of the human mind. Both ordinary experience
and the scientificstudy of memory have revealed a complex variety
of phenomena that are displayed by the humanbrain/mind. These
include the differentiation of memory into distinct types (e.g.,
short term vs.Long term; episodic vs. encyclopedic/semantic),complex
patterns of volatility and permanence, oftransfer and nontransfer
from short term to long term memory, of retrieval and retrieval
blockage,and so on. Why do we store some experiences structured
as episodes, while others are stored in anonepisodic format? Why
is it so difficult to hold certain types of mental representations
in memory for more than a few seconds? Why do are trains of thought
often disappear wheninterrupted, and why indeed is "consciousness"
or Tulving's "autonoetic awareness" so volatile?Evolutionary
analyses of the task demands on memory in a multimodular mind
suggest a series ofexplanations about why memory and consciousness
are organized as they are, and a series ofhypotheses about the
modular and functional nature of memory organization which have
yet to betested. In particular, it suggests that different modules
have their own proprietary forms ofmemory and rules for rapid
or slow erasure, that episodic memory was strongly shaped by thedemands
of social interaction, and that a primary function of consciousness
involves insulatingintermediately processed and unevaluated contents
to keep them from contaminating memoryarchives of information
already accepted as true, until processing is complete or the
information is evaluated
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.A Dynamic Model of Human Dispersal in a Land-Based Economy
Mary C. Towner
Department of Anthropology,
Animal Behavior Group
University of California, Davis
Davis, CA 95616;
e-mail: mctowner@ucdavis.edu
Dispersal from the natal area is a widespread phenomenon among
humans and non-humans alike.Multiple benefits and costs of dispersing
have been suggested, but few human studies (e.g., Clarkeand Low
1992, Koenig 1989) have considered the potential life-history
outcomes of dispersalcompared to philopatry. The decision whether
to disperse is investigated with a dynamicstate-dependent model
(c.f., Mangel and Clark, 1988). Using different probability functions
forthe likelihood of surviving dispersal, marrying, and inheriting
parental wealth, the modeldetermines whether dispersal results
in the highest fitness returns for the individual at each timestep.
Optimal dispersal strategies are predicted for different contexts,
and the sensitivity ofdispersal behavior to variation in life-history
parameters such as age and marital status is tested.The model's
results are compared to preliminary findings from an historical
study of dispersal in18th and early l9th century Oakham, Massachusetts.
Back to Top
Documenting Patterns of Violence Earlier Societies: The Problems
and Promise of Using Bioarchaeological Data for Testing Evolutionary
Theories
Phillip L. Walker
Department of Anthropology,
University of California, Santa Barbara,
Santa Barbara, CA 93196.
E-Mail: walker@alishaw.ucsb.edu
How have patterns of human aggression varied through time? This
is a historical question that has important implications for understanding
the evolution of modern human aggressive behavior.In contrast
to historical records and ethnographic reports, human skeletal
remains provide a directsource of evidence regarding patterns
of violence in both prehistoric and historically documented societies.
However, using skeletal data to reconstruct ancient aggressive
behavior is not withoutits pitfalls. This is well illustrated
by recent reinterpretations of skeletal evidence for head-huntingand
cannibalism in Homo erectus and Neanderthal populations. Although
interpersonal violenceclearly did occur in early human populations,
small sample sizes and problems of age and sexdetermination limit
the value of these data for testing evolutionary theories.Studies
of large, well-documented skeletal collections from more recent
populations, in contrast,show considerable promise as a source
of data for testing theories of human aggression. This is illustrated
by evidence for temporal-spatial variation in cranial trauma and
arrow wounds among prehistoric California Indians and the absence
of skeletal evidence for the "battered child syndrome"
among ancient hunter gatherers.
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Fluctuating asymmetry as a measure of human developmental stability.
Sally Walters
Dept. of Psychology,
Simon Fraser University,
Burnaby, BC, Canada V5A 1S6
Internet: walters@sfu.ca
Developmental stability is the ability of an individual to produce
exactly its species-specificphenotype in the face of environmental
and physiological disruptions that occur duringdevelopment. Heterozygosity
is associated with greater developmental stability; the developmentof
homozygous individuals is more likely to be disrupted by pathogens,
stress, extremetemperatures, etc. Symmetry of bilateral characteristics
is the normal developmental design;deviations from symmetry occur
when an individual is unable to compensate for environmental orgenetic
disruptions in development. A large animal literature exists on
the use of fluctuatingasymmetry (FA) to measure developmental
stability. FA refers to asymmetry of normallybilaterally symmetrical
characteristics when the population asymmetry mean for that trait
is zeroand variability is normally distributed. The direction
of asymmetry fluctuates randomly acrossindividuals. The use of
FA in humans is a recent phenomenon, and at present there are
severalmethods for measuring it; researchers in different fields
tend to use different methods. This posterreviews the methodologies
used to measure human FA, and outlines the implications of these
forevolutionary researchers, in particular with respect to good
genes models of female choice whichpredict that female preference
for male viability will be expressed by preference for low male
FA.
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Reproductive Success in Relation to Resource-Access in Two Different
Parishes in Central Norway During the Period 1700-1900.
Annelise Wara, Eivenh R skaft, & Anne Elisabeth Djupvik
Dept of Zoology,
University of Trondheim,
N-7055 Dragvoll, Norway
E-Mail: annelise.wara@avh.unit.no
Data for family size, child survival rate, and frequency of children
that became married were analyzed-with respect to resource-access,
and the year of first marriage of their parents during the period
1700 - l900 AD in two different parishes of Central Norway. The
first parish, Sm la, is an island located at the coast, where
people had better and more reliable access to food resources because
of in shore fishing, and people was occupied both in farming and
fishing. The other parish;Soknedal, is a small inland and an agricultural
parish, situated between 200 and 00 m above sea level, with very
unequal distribution of resources among landowners and land-less
people.Therefore, we predict that on Sm la, there should not be
any differences in reproductive strategies according to social
status. But on the other hand, in Soknedal, the unequal distribution
of resources between people of different social groups, would
effect reproductive success, where landowners will out-reproduce
land less people.Access to resources, or social status, was significant
in explaining the observed variation inreproductive success in
Soknedal, and, as predicted, the variation in family size was
much smalleron Sm la. Our results support the prediction that
social status explains very little of the variationin family size
when the difference in access to resources between people of high
and low statusare small, such as the situation on Sm la.
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.
Motivation and affect regulation: A psychodynamic-cognitive-evolutionary
model
Drew Westen, Ph.D.
Harvard Medical School and the Cambridge Hospital
1493 Cambridge St.,
Cambridge MA 02139
e-mail: dw@isr.harvard.edu
The paper presents a model of motivation and affect regulation
that integrates research and theory from psychodynamic, cognitive,
and evolutionary perspectives. It proposes that feelings are evolved
mechanisms for the selective retention of behavioral and mental
responses. Individuals select behaviors, coping strategies, and
defensive strategies that regulate aversive affective state,and
maximize pleasurable ones, with or without conscious awareness.
Just as humans and other organisms are prepared to associate tastes
with nausea, they are emotionally prepared to develop concern
for these with whom they are highly familiar (and hence likely
either related or cooperatively engaged), to avoid sexual contact
with people with whom they were familiar early in life, to fear
infidelity in mates in whom they invest resources or upon whose
resources they rely,etc. The utility of the model is demonstrated
through research on depression and borderline personality disorder
and through a reinterpretation of several disparate traditions
in social psychology, including many classic experiments on social
influence.
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Risk-taking and Homicide
Margo Wilson and Martin Daly
Dept. of Psychology
McMaster University,
Hamilton, Ontario, Canada L8S 4Kl
E-mail: Wilson@McMaster.CA and Daly@McMaster.CA
Homicides can often be characterized as incidents in which one
or more parties accept dangerousrisks. Although the fatal outcome
may not be anyone's "optimum" nor even "intended"
by eitherparty, certain kinds of homicides may nevertheless provide
a valid assay of variations in riskacceptance. Criminologists
have remarked that offenders' judgments and actions often betray
aninsensitivity to the benefits of foregoing immediate gratification
for greater future benefits, henceexhibiting short "time
horizons". These criminologists have apparently assumed that
the costs andbenefits of present rewards versus future rewards
are the same regardless of adult lifestage andregardless of social
and economic circumstances. Evolution-minded "criminologists"
wouldassume otherwise: all else equal, risk-taking and discounting
the future might be expected to besensitive to lifestage and circumstance.
Analyses of Chicago homicides support theevolution-minded "criminologists".
Back to Top
Consensual Nonmonogamy: Challenging Evolutionary Directives
Leanna Wolfe
Antioch University:
13274 Fiji Way -
Marina del Rey, CA 90292
E-mail: LAWolfe@aol.com
Evolutionary Psychology posits that human mate-selection preferences
are rooted in our evolutionary past. Males are attracted to hour-glass
shaped females because such females in ancestral times were likely
to be fertile though not yet pregnant. Simply put, this taste
proved to be a viable reproductive strategy. Meanwhile, ancestral
females were most inclined to pair off with the males who sported
the ancestral equivalence of a believable porsche-gold card-mansion
display. Today, such ancestral directives are openly discounted
by practitioners of consensual
nonmonogamy. In the world of people who practice swinging, group
tantric rituals, andpolyamory a unique set of cultural behaviors
have been fashioned. Traditional standards forfemale beauty are
put aside as are traditional measures of male provisioning/protection.
My talkwill examine the "new rules" as well as the content
and spirit of the agreements made betweenconsensual nonmonogamists.
Do these "evolutionary rebels" live up to what they
proclaim? Andif not, can we look to the sway of ancestral reproductive
strategies to explain why?
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Can Sexual Selection Explain The Increased Prevalence of Anxiety
Disorders in Women?
Elizabeth A. Young, Randolph M. Nesse
University of Michigan,
Department of Psychiatry,
Ann Arbor, MI 48109-0704
EAYoung@umich.edu
Anxiety disorders are 2-3 times more prevalent in women than men.
Data on infant temperamentfrom Kagan have found that more than
90% of the shy, inhibited children are female. While mostpsychiatric
and epidemiological data seek to answer the question "Why
are women more anxiousthan men?", we propose that the real
reason is "Why do men show insufficient anxiety?" Weknow
that men take more risks, are involved in more accidents and injuries
and ultimately have ashorter life span than women because of their
risk taking behavior. We also have evidence (Nesse& Klass,
1994) that men and women do not differ in their perceptions of
risks of specific eventshappening to themselves or others. If
the function of anxiety and fear is to signal an unsafe/riskysituation,
then men clearly demonstrate behavioral evidence of decreased
anxiety. Following Low(1994), and Konner (1990), we assess evidence
for and against the hypothesis that the decreasedanxiety in men
is a tradeoff that has been sharped to sacrifice defense benefits
for the sake ofmating advantage. This predicts sex differences
in anxiety susceptibility as a function of matingsystem, decreased
male survival because of risk taking, and female preference for
males who showless anxiety than would be in their individual self
interests. We also consider proximate mechanisms that may mediate
these sex differences and possible clinical implications.
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Detection of Ethnicity and Ethnocentrism: Natural or Artificial
Selection?
John P. Ziker
Department of Anthropology,
University of California,
Santa Barbara, CA 931066500
jpz@ucsbuxa.ucsb.edu
Ethnocentrism is a facultative adaptation operating within human
sociality. In this paper Ipropose necessary conditions for the
activation of ethnocentric motivations and for the calibrationof
ethnicity detection. That ethnocentrism can utilize hierarchical
and rapidly changing definitionsof ethnicity is the main problem
in developing ultimate- and proximate-level hypotheses. In ourevolutionary
past, what we classify as ethnocentrism probably served to motivate
individuals withcommon genetic interests in coalitional aggression
and defense. Although ethnocentrism probably does not function
to increase inclusive fitness when coalitions comprise non-relatives,
it still canplay a role in motivating individuals for warfare,
conflict, sport and other factional ventures. Isuggest that the
role of kinship cooperation is not adequately considered in existing
explanationsof the formation of ethnic representations.
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