Human Behavior &

Evolution Society

Program for the Eighth Annual Meeting of the

Human Behavior and Evolution Society

NOTE:  This was scanned from a printed program.  There are scanning errors in some of the following abstracts.

Welcome to HBES ‘96

Welcome to Northwestern University. Most activities will take place in two general areas. Lodging and meals are in Foster Walker Dorm, and the academic portion of the conference is at Norris Center, Northwestern’s student union. A map of campus is included in this program.

Your local hosts are Bill Irons and Jack Beckstrom. For most issues related to conference logistics, you should find Bill Irons. The program committee consisted of Linda Mealey and Mike Bailey, with input from Bill and Jack.

Nigbtlife. At least three decent bars are near campus. They are: MyBar (most subdued), near Clark and Sherman, Tommy Nevins, on Sherman south of Grove, and the Keg (loudest), on Grove near Sherman.

HBES Officers:

Richard D. Alexander President

Kevin McDonald Secretary/Archivist

Napolean A. Chagnon Past President

Patrick McKim Treasurer

Margo Wilson President Elect

Joanna Scheib

Student Representative

Randolph Nesse Chair Publications Committee

Michael McGuire

Editor-in-Chief

Ethology and Sociobiology

Elizabeth Hill Newsletter Editor

Martin Daly

Associate Editor

Ethology and Sociobiology

Executive Council:

David Buss

Sarah Blaffer Hrdy

Monique IBorgerhoff Mulder

Lee Cronk

William Irons

Jane Lancaster

A Study of Darwinian Aesthetics: Health and Preferences

Tamara Addison

Department of Psychology, McMaster University, Hamilton, Ontario L8S 4K1

g9017681@mcmaster.ca

When a person reacts to a particular scene his or her judgments are a reflection not merely of the features of the stimulus but also how the stimulus is interpreted. People seem to like scenes of places which offer interesting and productive possibilities. Images of natural landscapes and vegetation containing cues of healthy plants are expected to be preferred over ones with unhealthy plants. In a computerized photo­questionnaire experiment, images of plants were manipulated electronically to create variants of the images with only cues of healthiness altered. Healthiness cues included leaf discoloration and damage (holes). In addition, the presence or absence of an insect offered alternative interpretations for the state of the leaves. People rated, on a 7­point Likert scale, the healthiness of the plants and how much they liked the scene. Healthiness and preference judgments were significantly higher for 'healthy' leaves. People prefer looking at healthy plants.

A New Aesthetics

Nancy E. Aiken

P.O. Box 27

Guysville, Ohio 45735

614­662­5701

If art is looked at as a species­specific behavior that has evolved for adaptive purposes, a new aesthetic is needed. A new aesthetic is needed, anyway, because the old aesthetic has fundamental problems in logic, in being exclusive (not all art is included) and, because of its exclusiveness, its ties to artistic traditions of the West. Other contemporary opponents of the old aesthetics (postmodern deconstructionists), because they offer only a reaction to the old aesthetics, also are rebutted. This new aesthetics observes aesthetic behavior and finds: aesthetic behavior includes art making and art appreciating, art can be simple (self­adornment) or complex (the Taj Mahal), all normal human beings are art makers and art appreciators, all human populations through time and geography have produced art. This new aesthetic looks for adaptive purpose in art and finds that ultimately art binds human society together. The new aesthetics asks questions such as: how does art bind societies together, what is the effect of culture on aesthetic behavior, what are the political aspects of aesthetic behavior, what new criticism will result from the new aesthetics. The new aesthetics does not ask what art ought to be (which is what the old aesthetics asks), but what art is.

From Adaptation To Illness: The Case Of Depression

Nicholas B. Allen, Ph.D.

Oregon Research Institute

1715 Franklin Boulevard

Eugene, OR 97403­1983

Evolutionary analyses of depression have often been compromised by a lack of precision concerning which forms of depression were selected for their adaptive utility, and which forms represent pathologies based on adaptive mechanisms. In order to establish a strong argument for the adaptive nature of a putatively evolved mechanism one must specify the "fit" of the mechanism to its environment of evolutionary adaptation, i.e., the mechanism must demonstrate a complex and specific adaptive fit to this environment. Based on these principles, this paper will argue that depressed mood, but not clinical form of depression, satisfy such criteria for an adaptive mechanism. Furthermore, it will be argues that the environment to which human depressed mood is adapted is a specifically social one. Based on these principles a number of logical possibilities regarding the emergence of clinically depressed states will be described. They are (1) poor fit between the adaptive mechanism of depressed mood and the environment, (2) abnormal threshold of activation of one or more of the psychobiological mechanisms that form the substratum the depressive response, and (3) functional breakdown of these psychobiological mechanisms. Empirical research on the cognitive psychology, epidemiology, phenomenology, and actiology of depression will be used to support and illustrate these arguments.

"A Sociobiological Deconstruction of the "Good Husband/Bad

Husband Motif in Dene Oral Narratives"

Wayne E. Allen

The Dene Athapaskans of Subarctic Candada have, until quite recently, maintained an enormous body of traditional oral narratives that are recounted by the elders in their indigenous language. The explicit purpose of these orally­transmitted narratives has been to teach males and females, both young and old, what it is to be "capable" in the traditional bush­oriented lifeway. Implicit in these narratives, though, are themes and motifs ­ e.g., violent male­male competition, male sexual jealousy, parental investment and parent­offspring conflict, sibling rivalries, status striving and dominance hierarchies, selective female infanticide, and mate selection criteria to name but a few ­ that are amenable to a sociobiological deconstruction and analysis.

One genre of these narratives has to do with a group marriage theme, where there are two husbands, a "good" one and a "bad" one, who end up competing with each other for the two wives they share. This situation always precipitates an episode of male sexual jealousy on the part of the "bad" husband, who initiates the male­male competition over the two females wherein he tries to kill the "good" husband. These narratives always end in the death of the "bad" husband by the hand or actions of the "good" husband. In this way an untenable group marriage becomes a tenable polygynous marriage.

Two of these narratives, accompanied by complete illustrations provided by a Dene informant, will be presented with a brief analysis and discussion to follow.

Determinants of parental expenditures among Albuquerque men.

Kermyt G. Anderson, Hillard S. Kaplan and Jane B. Lancaster

Dept. of Anthropology, Univ. of New Mexico, Albuquerque, NM 87131

We measured the financial expenditures of 385 men on the 1093 children they had parented, and tested two models to explain the observations. The Capital model, based on the capital labor market theory (Kaplan et al. 1995), predicts that, controlling for income, parents with more embodied capital will expend more on their offspring. As predicted, the father's embodied capital was a significant predictor of parental expenditures for offspring younger than 24, and was strongest for children ages 18­23; parental embodied capital had no effect for offspring age 24 and older. The second model, the Livebio model, examined the interaction between the child's residency pattern and relationship to the informant. The success of the model varied with the child's age. For children age 18 and over, step­children living elsewhere received less financial investment than other children; however, the data did not support the prediction that men spent more on genetic children living with them than on all other offspring. For children under age 18, no relationship was found between the child's residency pattern or biological relationship and the amount the informant spent on the child. These somewhat surprising results may result from financial expenditures measuring only one aspect of parental investment.

Sexual Orientation, Masculinity­Femininity, and Mating Psychology

J. Michael Bailey, Department of Psychology, Northwestern University, Evanston, IL 60208­2710

On average and in some respects, homosexual people are somewhat similar to the opposite sex. In other respects, they are identical to same­sex heterosexual people. I present results from a program of research aiming to delineate the ways in which gay men and/or lesbians are masculine or feminine. Studies have examined both homosexual and heterosexual, and transsexual individuals. Results have implications for theories of sexual differentiation, the modularity of sex­differentiated adaptations, and the explanations of specific sex­differentiated adaptations.

Individual Differences in Sexually Dimorphic Traits

J. Michael Bailey, Department of Psychology, Northwestern University

Evanston, IL 60208­2710

Evolutionary psychologists have focused their attention on explanations of sex differences. Existing explanations imply tha thte sexes should be entirely distinct on relevant traits. In fact, however, relevant traits show considerable overlap between the sexes, and some of the within­sex variation is heritable. I present examples from both American samples and the Australian Twin Registry.

Should Societies Practice Eugenics with Respect to Reproduction?

Professor Carl Jay Bajema, Biology Department, Grand Valley State University, Allendale, Michigan 49401

The numerous socioeconomic changes taking place in human societies have an effect on the direction and the intensity of natural selection with respect to the reproductive success of genes affecting human mental and physical health. The philosopher Philip Kitcher discusses the inescapability of eugenics in his new book The Lives to Come: The Genetic Revolution and Human Possibilities. Kitcher asks the crucial question "Are we morally committed to courses of action that will utterly debase the lives of our descendants?" Unfortunately Kitcher neglects a very rich intellectual humanist tradition of scientific and ethical discussion of the genetic/cultural implications of social policies. How have the biologist Garrett Hardin (Nature and Man's Fate, "Tragedy of the Commons") and the theologian Joseph Fletcher (Situation Ethics) addressed the issues of population quantity/quality?

Secular Changes in Standards of Bodily Attractiveness in Women: Tests of Evolutionary Predictions

Nigel Barber

Department of Psychology, Box 549037

Birmingham­Southern College, Arkadelphia Road

Birmingham, AL 35254

Women vary in the relative emphasis which is placed on work and marriage as economic strategies. Since success at work is likely to be favored by a more slender body build while success in marriage is favored by curvaceousness, changing standards of bodily attractiveness for women should be predictable from economic and reproductive variables. This hypothesis was tested using published data on bodily curvaceousness in Vogue models. Results tended to support the hypothesis. Curvaceousness is reduced as the economy expands, and as women participate more in the work force and in higher education and reproduce at a lower rate. Results (which replicate and extend similar findings in the sociological literature) suggest that fashions of bodily attractiveness are influenced by an evolved psychology of mate selection.

Against The Ghettoization Of Sociology

Jerome H. Barkow Department of

Sociology and Social Anthropology Dalhousie University Halifax, N.S.

CANADA B3H 3J5

One would expect sociologists to be fascinated with the evolutionary perspective because the latter has yielded so much insight into some of their favorite topics, including crime (particularly homicide, rape, and sociopathy), social stratification and hierarchy, gender and sex, and social exchange. Uninterest in and even antipathy towards the evolutionary approach apparently stems from the Durkheimian insistence that sociology must not be clearly linked to biology or psychology, the historic use of biology and evolution to justify social iniquity and inequity, species chauvinism, tension between sociological feminism and modern science, the scant familiarity of many sociologists with elementary Darwin, and the rise of a strongly anti­ positivistic "postmodern" school strongly influenced by literary criticism rather than by empirical science. These factors are much weaker in the other social sciences, which have correspondingly been much more ready to think from an evolutionary perspective. HBES members can work to influence sociologists and student sociologists by: contacting the authors of sociology textbooks directly in order to acquaint these influential individuals with relevant research and theory; publishing in journals read by sociologists; and by discussing these issues in undergraduate courses sociology students often take. The goal would be to end the increasing ghettoization of sociology.

Sexual Selection as a Causal Factor of Gender Differences in Self­esteem

Alicia Barr, Stephanie L. Brown, Emily Brannon & Angela D. Bryan

Arizona State University

Sexual selection may have favored females and males whose self­esteem was based on self­appraisals of reproductive fitness. If self­esteem measures can serve as a proxy for perceived reproductive fitness, then it is possible that gender differences in self­esteem reflect gender differences in perceived mate value. In particular, resource acquisition should be more important to male self­esteem and physical attractiveness should be more important to female self­esteem. To test this hypothesis, one­hundred and sixty­two male and female students at Arizona State University responded to a personality inventory which assessed self­esteem as well as other dimensions of the self­concept. Specifically, subjects responded to questions concerning physical attractiveness, ability to garner resources, mating potential, social competence, relationship attachments and athletic ability. Subjects' Rosenberg self­esteem scores were regressed on each of the above dimensions. As predicted, a three­way interaction between gender, physical attractiveness and resource potential indicated that a male's self­esteem score was more strongly correlated with his resource potential than his physical attractiveness, whereas a female's self­esteem score was more strongly correlated with her physical attractiveness than her resource potential. Results are discussed in terms of causal factors associated with self­esteem.

Psychological Trauma and Social Polarization

John O. Beahrs, M.E. (116A­OPC)

Portland D.V.A. Medical Center, P.O. Box 1036, Portland, OR 97207

and Department of Psychiatry, Oregon Health Sciences University

Psychological trauma leads to persisting cognitive, affective, and interpersonal sequelae: cognitively, one is more likely to perceive polar extremes within what are better viewed as continua; affectively, avoidance occurs in tension with a quasi­addictive drive to reenact the trauma; and interpersonally, trauma heightens and rigidifies humans' penchant for dichotomizing significant others into allies and enemies. With today's forensic psychiatry "adult delayed recall" controversy a clear case in point, traumatized individuals tend to unite into tightly knit in­groups, like cults; while others are denigrated and defined as enemies. This often creates new enmities where objective interests had formerly clashed only minimally. Traumatic social polarization is hypothesized to be adaptive in dangerous but stable environments where alliances and enmities are likely to persist for decades or more., In rapidly changing environments, the process becomes increasingly dysfunctional; and currently, is a major obstacle to cooperative social problem­solving. Discussion will focus on the risks and benefits of different strategies ­­ clinical, legal, social, and political ­­ for attemting to master this obstacle.

Depression as an Evolutionary Strategy

Aaron T. Beck, M.D.

Department of Psychiatry

University of Pensylvania

Philadelphia, PA 19104­2648

In depression, the patient perceives radically diminished resources (loss of close relationship, shrinkage of financial resources), decreased social influence (due to loss of social attractiveness), and diminished internal assets (due to illness, etc. With the reduction of resources, the value of social influence and internal attributes to self as well as others drops to zero. The catastrophic drop in self­esteem ("worthless, useless") triggers a program involving an overwhelming sense of fatigue and loss of motivation.

The picture in mania is the mirror opposite; the patient perceives an intensification and expansion in her sphere of influence and personal attributes: superior, highly worthwhile, and excessive energy and motivation. The alternation between depression and mania may be viewed as atavistic strategies designed to adapt to the perceived shrinkage or expansion of available resources. Both clinical and ethological evidence support the notion that following defeat or deprivation, the individual slows down, apparently "gives up." I propose that the function of depression in the ancestral environment was to conserve energy and resources whereas mania served to expand resources. The merits and the shortcomings of the formulation will be discussed.

Patterns of Attachment, Mating and Parenting: An Evolutionary Interpretation

Jay Belsky

Human Development and Family Studies

Penn State University

University Park, PA 16802

A modern evolutionary perspective is brought to bear on the three core patterns of attachment­­insecure­avoidant, secure and insecure­resistant­­after reviewing some basic tenets of life­history theory which emphasize the role of environmental influences on reproduction. Mating and parenting correlates of secure/autonomous, avoidant/dismissing and resistant/preoccupied attachment patterns are reviewed and the argument is advanced that security evolved to promote mutually­beneficial interpersonal relations and high investment parenting; that avodiant/dismissing attachment evolved to promote opportunistic and disproportionately self­serving interpersonal relations and low investment parenting; and that resistant/preoccupied attachment evolved to foster "helper­at­the­next" behavior and indirect reproduction. The role of constitutional temperament and plasticity in development are also considered in this facultative analysis of early and enduring attachment patterns.

Mate preferences: Implications for gender differences in depression and body dissatisfaction

Souhir Ben Hamida

Northwestern University

We combine two models to investigate gender differences in depression. The reformulated learned helplessness theory (Abramson, Seligman, & Teasdale, 1978) outlines the mechanisms by which uncontrollability can lead to dysphoria. We use mate preferences theory (Buss, 1989) to argue that characteristics that increase women's mate value (youth, attractiveness) are more immutable than traits that increase men's desirability (status, industriousness). Women's reduced control over desirable attributes may increase their risk for helplessness, dysphoria, and low self­esteem. We conducted two studies to test this hypothesis, one using 150 undergraduates, another using 301 older adults. Subjects rated the importance of various traits when selecting partners, and their degree of perceived personal control over the same traits. Men's controllability ratings were higher on traits that women rated as more important in mate selection, compared to women's controllability ratings on traits that men rated as more important in partner selection (college and older sample: e.s.=1.75; e.s.=1.03). Generalized gender differences in perceived controllability could not account for these findings. Traits on which women are selected appear to be more uncontrollable than those on which men are selected, suggesting one reason that women are at higher risk for depression and body dissatisfaction.

Exploring The Labyrinth From Dominance To Paternity In Primates

Fred B. Bercovitch

Caribbean Primate Research Center

One of the most consistent findings to emerge from the primate literature is the inconsistent relationship between rank and reproduction among males. Variables that can affect the chances of high ranking males mating more than low ranking males include the number of females in a group, the degree of cycle synchrony, the length of the mating season or sexually receptive period, the number of males in a group, the extent to which males can adopt alternative reproductive tactics, physical features of the environment, morphological attributes, and patterns of mate choice. Comparing behavioral assessments of paternity with actual paternity has provided insights into the actual payoffs of different male reproductive strategies, but the use of genetic data has revealed the same inconsistent link between male rank and reproduction. The relationship between dominance and reproduction in male primates is a conditional probability, not a predictable correlation.

Address all correspondence to:

Fred B. Bercovitch

Caribbean Primate Research Center

P. O. Box 1053

Sabana Seca, PR 00952

(809) 784­6619; FAX: (809) 795­6700

Father Absence and Mate Preference: Do Birds of a Feather Mate Together?

Gerald Beroldi

Department of Psychology, Simon Fraser University

Burnaby, BC; Canada V5A 1S6

email: gerald_beroldi@sfu.ca

This poster is on two works in progress. One is a review of the evolutionary and non­evolutionary literature self­identified as father­absent. The theory upon which the evolutionary literature is based is within the Darwinian anthropology tradition. These works are from an evolutionary psychology perspective with an attempt to elucidate and test the psychological mechanism mediating the effect that father absence and presence has on the mating strategy of their off­spring. This review is planned to be the core of a broader review of the literature concerning the putative developmentally contingent effects of one's father presence in, or absence from, one's home during a critical period (age 0­5 or 0­7). This larger review in turn will be the basis for a study investigating a replication of these effects. The other work is a questionnaire that was developed to test the hypothesis mentioned by Harpending & Draper (1983) and Blain (1984) that individuals from father absent or present homes tend to choose mates from the same type of home. This questionnaire is for females, a future one will be for males.

Delayed Reciprocity And Tolerated Theft: The Behavioral Ecology Of Food Sharing Strategies

Rebecca L. Bliege Bird

Department of Anthropology

University of California, Davis 95616

Models derived from behavioral ecology may have the potential to explain a great deal of variability in food sharing patterns within and between human societies. I use quantitative observational data on the hunting and sharing of large animal prey (marine turtle) among the Meriam of the Torres Strait to test specific predictions of reciprocity­based and tolerated theft sharing models, evaluating the extent to which such models can account for the way in which prey are distributed after acquisition. I also evaluate the influence on sharing strategies of seasonal variability in the costs and benefits of pursuing prey. Prey are shared widely and unconditionally when costly to acquire, and more narrowly when acquisition costs are low. Hunters receive little consumption benefit when prey are shared widely, and only receive high consumption benefits when they hunt for their own household's consumption. I conclude that hunters seek both social and consumption benefits from prey and that these goals can be predicted according to seasonal variability in the costs of acquisition and the reproductive strategies of individual hunters.

The Group Mind: Groups As Complex Adaptive Systems

Howard Bloom and Michael Waller

National Coalition of Independent Scholars

howlbloom@aol.com

mwaller@comparator.win­uk.net

David Sloan Wilson has asked: "Can social groups evolve into functionally integrated units, similar to single organisms in their adaptive design?" This paper will argue that the answer is yes: social organisms often coalesce into what might be termed a group mind. John Hopfield's neural nets and J.H. Holland's Classifier Systems model the manner in which individual components combine to make each solo element a module in a learning machine. It will be argued that a complex of autonomic biological devices similarly orchestrate social individuals to function like components of a group brain. A range of studies will be cited indicating that these physiological systems, which we call comparator mechanisms, either shut down or invigorate the individual depending on its likely contribution to mastery of communal challenges. Examples will be drawn from honeybee colonies, bird swarms, lower primate bands, and human groups of all sizes. Intergroup competition and environmental change frequently place a high premium on the rapid generation of new, adaptive responses. Hence the ubiquity of genetic coalitions which energize or handicap their carriers to maximize their function as constituents of a collaborative intelligence.(186 words)

Five Mechanical Routes To Altruism

Chris Boehm

Department of Anthropology, University of Southern California

fax: 213­747­8571

Evolutionary biologists have relied exclusively upon inclusive fitness/reciprocal altruism arguments to explain altruistic behavior because group effects are so weak that they are inevitably swamped by individual (inclusive) effects. It is proposed, for humans, that five factors have made possible substantial augmentation of group effects at the expense of individual effects. The first four are cultural. Egalitarian leveling behavior and group consensus seeking reduce intra­group phenotypic variation among individuals, while group decisions and emergency decisions in particular amplify phenotypic variation among groups. In addition moral sanctioning of free­loaders and cheaters provides special reproductive advantages to altruists. There is also a genetic factor. Pleiotropic traits that are well­supported by inclusive fitness may be inextricably coupled with altruistic traits that are moderately costly, and therefore can be maintained in spite of their costs. By taking these five factors into account, a selection scenario can be created in which many types of (non­kin) altruism are readily explained. The realigned balance of power between individual and group levels of selection helps to explain strong ambivalences found in human nature.(180 words)

Status Reinforcement Behavior, Long Term Fitness, And The Evolution Of Conspicuous Consumption

James L. Boone and Karen Kessler

Human Evolutionary Ecology Program, Anthropology Dept., University of New Mexico

Albuquerque, NM 87131

e­mail: jboone@unm.edu

Most analyses of the correlation of socioeconomic status with reproductive success have treated wealth and status as a condition or outcome, focusing on the proximate benefits of socioeconomic status­­increased access to mates and higher fertility­­rather than treating status reinforcement as an ongoing social strategy which itself involves both costs and benefits. In many ranked and stratified societies considerable resources are invested purely in status reinforcement-resources that could have gone into further production of offspring. Why? We argue that the utility of status is not limited to the momentary benefits of greater access to resources. Rather, status reinforcement has evolved as a behavioral strategy that increases probability of survival through relatively infrequent, but recurrent demographic bottlenecks by determining individual/ familial priority of access to of resources accumulated, produced or defended collectively by the social group during periodic shortages. Maintaining priority of access requires expenditures in the form of defense costs and costly signalling, often in the form of conspicuous consumption. In many contexts such expenditures may divert resources away from further production of offspring, yet these short term costs are offset by the long term benefits of increased survivorship through recurrent crashes.

Evolutionary Analysis of Suicidal Ideation and Behavior

R. Michael Brown and Kirsten Melver

Department of Psychology

Pacific Lutheran University

Contemporary explanations of suicide view it as a pathological response to depression and hopelessness. The idea that at least some aspects of self­destructive motivation may be part of our evolutionary heritage has received little attention in spite of the exposition of a formal mathematical model outlining possible adaptive functions of suicide. In a recent study, we reported findings consistent with this model. We designed the present study to provide a more finely tuned analysis of fitness variables that appear related to components of suicide, and to determine how they might be related to another component of self­destructive motivation­­psychological pain. University students served as subjects, and variables were constructed from a questionnaire. Results indicated that psychological pain was highest among those individuals who considered themselves a burden to their kin, were low in reproductive potential, and had kin who were low in reproductive potential. Psychological pain accounted for more of the variance in suicidal ideation and behavior than did any of our other predictors. Taken together, our findings raise the possibility that suicidal ideation and behavior result from failed attempts to reduce psychological pain.

An Empirical Examination of the Evolutionary Mechanisms of Prosocial Behavior

Stephanie L. Brown, Brian P. Lewis, Robert B. Cialdini, Steven L. Neuberg, &

Carol Luce.

Department of Psychology, Arizona State University, Tempe, AZ 85287

Theories of reciprocal altruism and inclusive fitness posit that selection pressures have favored the existance of prosocial behavior. Since indiscriminate helping can be maladaptive, it is probable that helping another is predicated upon the perception that helping will enhance the giver's inclusive fitness either by benefiting kin or by engendering future help. One indicator of the extent to which helping serves this purpose may be the helper's perception that the recipient and the helper share a 'sense of self', either through kinship or intimacy. In order to test this prediction, 242 undergraduates were presented with a helping scenario that varied in the severity of the situation, and in the closeness of the target­­a stranger, aquaintance, close friend, or sibling. Participants were asked to report how much help they were willing to give the target, their emotional response to the person in need, and indicated the extent to which the target's identity overlapped with their own. Results indicate that as this overlap increased, so did the amount of help given. Additionally, as the helping situation became more severe, the difference in help as a function of perceived overlap became more pronounced. Structural equation modelling confirmed these results and demonstrated that emotional feelings toward the target had only an indirect effect on helping, mediated by the perception of self­target overlap.

The Glass Ceiling, the Gender Gap, and Evolutionary Biology

Kingsley R. Browne

Wayne State University Law School

Detroit, Michigan 48202

The "glass ceiling" and the "gender gap" in compensation are commonly viewed as indicia of unfairness to women and attributed to inappropriate employer behavior and sexist socialization patterns. However, well­known stereotypes of men as more competitive, more driven toward acquisition of status and resources, and more inclined to take risks than women, and stereotypes of women as more nurturant, more risk averse, less greedy, and less single­minded than men are true as generalizations. These temperamental sex differences have an underlying biological basis that appears to be a legacy of our evolutionary history.

These sex differences are responsible for much of the sex difference in workplace outcomes. Characteristics of successful executives - both male and female - include the "male" traits of aggressiveness, ambition and drive, a "passion for success," and a willingness to take risks. Factors that explain differences in overall compensation for men and women include number of hours worked, riskiness of job (both in terms of physical risk and "career risk"), amount of job­related schooling, and pleasantness of surroundings.

From Vigilance to Violence: Mate Retention Tactics in Married Couples

David M. Buss and Todd Shackelford

Department of Psychology, University of Michigan, Ann Arbor MI 48109­1109

Although much research has explored the adaptive problems of mate selection and mate attraction, little research has been conducted on the adaptive problem of mate retention, despite the fact that more than 50% of all married couples in the United States end up divorced. This study was designed to test seven evolutionary psychological hypotheses about the determinants of mate retention in a sample of married individuals (N = 214). We assessed the usage of 19 mate retention tactics, ranging from vigilance to violence. Empirical support was found for the hypotheses that men's, but not women's, mate retention effort is a function of the partner's youth and physical attractiveness, even after statistically controlling for the man's age and the length of the couple's relationship. Women's mate retention, although less predictable than that of men, was correlated with the effort allocated by their husbands to the problem of hierarchy negotiation. Overall, men reported using higher frequencies of resource display, vigilance, and intrasexual threats to retain their mates. Women reported using higher frequencies of appearance enhancement, emotional manipulation, jealousy induction, and derogation of competitors. Discussion focuses on the evolutionary psychology of mate retention and the importance of this psychology for understanding spousal violence.

Sex Differences in Partner Preferences: A Replication and Extension in The Netherlands

Bram P. Buunk, Astrid Warntjes & Douglas T. Kenrick

University of Groningen, The Netherlands

The present study among 137 subjects examined sex differences in partner preferences in The Netherlands. Subjects were either 20, 30, 40, 50 or 60 years of age. In line with predictions based upon evolutionary theory the results showed that females, regardless of their age, preferred partners a few years younger or a few years older than themselves. In contrast, among males the discrepancy between one's own age and the preferred age of a potential partner was larger as males were older. For instance, males of 60 years old preferred females with a minimum age of 35, and a maximum age of 53. Females found a high income, a high level of education, dominance, intelligence and social status of a partner more important than males, whereas males found physical attractiveness more important. The higher the level of involvement with a potential partner (sexual fantasy, short­term sexual affair, fall in love, steady relationship, marry), the higher the preferred educational level, dominance, and physical attractiveness of the partner. Males and females required the highest level of physical attractiveness for a partner about whom they would have sexual fantasies. Some evidence was found that males had lower standards than females for short­term sexual affairs.

What Should Evolutionary Critics Do?

Joseph Carroll

English Department, UM­­St. Louis

The effort to study literature from an evolutionary standpoint has only just begun, and there is no consensus among the practitioners as to precisely what it is they can and should be doing. Many Darwinists harbor understandable doubts as to whether (as John Constable puts it) "biologized criticism" can be "an integrated part of human behavioral science." Among those who have attempted any such integration, the most common form of practice so far has been to examine literary texts with the intent of extracting examples of behavior that illustrate principles of evolutionary psychology, especially reproductive psychology. I shall argue that "criticism"­­the analytic, interpretive study of individual texts and groups of texts­­is a necessary precondition for any literary study likely to produce substantive findings of some value and interest to human behavioral science. I shall argue also that combing literary texts for behavior that illustrates evolutionary psychology is at best a rudimentary form of analysis. A more fruitful method would be, first, to use evolutionary psychology to establish a common analytic framework for understanding meaning in literary texts, and second, for specific texts, to examine the way proximate motives interact with complex cultural situations to produce representations that are often far removed from simple illustrations of fitness maximization.

Variation in Female Competition

Elizabeth Cashdan

University of Utah

Reproductive trade­offs and differences in access to resources favor differences in reproductive strategies among women. These differences affect the ways in which women compete with each other.

This study, which uses competition diaries, indicates that women are more competitive with other women over men when either (a) the women come from poor families, or (b) they are sexually unrestricted (willing to engage in sex with less evidence of long­term commitment

from a man). These findings are consistent with literature reports showing aggressive competition among women for the attention of desirable males in communities characterized by low paternity

confidence and economic scarcity. Competition among women over mates may be more acute in such communities both because of limited economic resources and because the presence of sexually unrestricted women poses a greater threat to a woman intent on keeping her mate.

As women become older and less fertile, their mate value should decline. We might expect, therefore, that they will become less sexually restricted as they become older. This expectation is

supported both by literature accounts of female­female aggression and by this data set. A woman's competitive strategies may be expected to shift accordingly as she ages.

Are Group Minds Self­Organizing Systems?

Hiram Caton

Griffith University, Brisbane, Australia

h.caton.hum.gu.edu.au

Recent applications of nonlinear mathematics to the description of animal aggregations (Kauffman) and to game theory (Nowak & Sigmund) suggest that self­organisation may be the 'missing link' in neo­Darwinian orthodoxy. After mentioning some trouble spots in neo­Darwinism (saltationism in the fossil record), the paper notes the forgotten tradition of group selection in evolutionary biology (Allee), and current work on group selection (D S Wilson, Boyd & Richerson). Although the group mind(s) is widely regarded as a discredited concept, its use under other names is pandemic in the social and evolutionary sciences. The central theoretical blockage is the apparent absence of a theory able to treat individual events as both individual and as aggregates in non­reversible real time. Nonlinear mathematics provides many avenues of approach. The central empirical blockage is the apparent absence of measures of 'groupness' of group behavior. There are many such measures; the paper attends especially to ethological description of behavior synchrony. I conclude with a clarification about just what is attributed when an aggregate is said to be of a common mind. I argue that the attribution involves a necessary cognitive illusion, similar perceptual illusions. Its evolutionary origin is Homo sapiens' facultative eusociality. Its social effect is to mobilize the appearance of an authoritative or unchallengeable consensus, which in turn gives effect to sudden and dramatic group action on small and grand scales.(229 words)

Attachment And Time Preference: Algorithms For The Contingent Development Of Reproductive Strategies

James S. Chisholm

Department of Anatomy and Human Biology

University of Western Australia

Nedlands, WA 6907

Australia

This paper investigates hypotheses drawn from two sources: (1) Belsky, Steinberg and Draper's (1991) attachment theory model of the development of reproductive strategies, and (2) recent life history models and comparative data that suggest that environmental risk and uncertainty may be potent determinants of the optimal tradeoff between current and future reproduction. A retrospective, self­report study of 136 university women aged 19­25 showed that current recollections of early stress (environmental risk and uncertainty) were significantly related to individual differences in adult time preference and adult sexual behavior and attitudes, and that individual differences in time preference were significantly related to adult attachment organization and sexual behavior. These results are consistent with the view that perceptions of early stress index environmental risk and uncertainty and mediate the attachment process and the development of reproductive strategies. In this view individual differences in time preference are considered to be part of the attachment theoretical construct of internal working model, which itself is conceived as an evolved algorithm for the contingent development of alternative reproductive strategies.

KEY WORDS: Life history theory; Attachment theory; Reproductive strategies;

Early stress; Environmental risk and uncertainty; Sexual behavior of young

women.

Sex Differences in Spatial Mapping Strategies

Jean Choi and Irwin Silverman

York University, 4700 Keele St., Toronto, Ontario, M3J 1P3

Recent studies with humans have revealed sex differences in preferred strategies for route learning, with males disposed to Euclidean methods (the use of distance concepts and cardinal directions) and females to topographical techniques (the use of landmarks and relative directions). The present study was designed to assess whether these differences represented a default strategy on the part of females, compensating for their lesser general spatial abilities, or an evolved dimorphism. The latter view was based on the historical role of females as caretakers of the habitat and foragers for food, both of which would have required superior incidental recall of the location of objects. The evolved dimorphism theory was favored, particularly by data showing that route learning success was related to Euclidean strategy preferences for males only and topographical strategy preferences for females only. An attempt to establish whether strategy preferences were related to estrogen level yielded ambiguous findings.

Mate Choice And Kin: "Gosh, Your Cousin Is Ugly!"

Melissa L. Citro and Jack Demarest

Monmouth University, Department of Psychology

West Long Branch, NJ 07764

Research on mate choice has focused on characteristics of potential mates. Inclusive fitness theory suggests that the traits of close kin may also affect mate preferences. Using written scenarios, two studies examined how likely men and women would get involved with a person whose kin exhibited one of 8 traits (attractiveness, youthfulness, leadership, success, wealth, faithfulness, nurturing or family oriented, faithfulness, infertility, or a genetic disorder leading to death). This choice was compared to a potential mate whose relatives did not have the trait. Kinship was either close (r = 0.5) or distant (r < 0.26) and the level of commitment to the relationship varied (one date, sexual intimacy, serious dating, or marriage). Results show that males were less selective than females concerning sexual intimacy, but more selective when it came to marriage. Men preferred a mate with attractive kin; women preferred a mate with financially successful kin. Those with kin who had a genetic defect (infertility or a fatal disorder) were highly unlikely to be selected as mates.

Jealousy: Adaptive or Destructive?

Heather Claypool and Virgil Sheets

Department of Psychology

Indiana State University

Terre Haute, IN 47809

Evolutionary theorists argue that jealousy is an adaptive psychological mechanism that promotes mate retention and thus relationship stability. Social psychologists, in contrast, contend that jealousy is an unsettling force that promotes relationship dissolution. To test these contrary predictions, college students involved in a romantic relationship were surveyed regarding jealousy in the fall, and recontacted in the spring to assess the status of the relationship. Cross­sectional analyses showed that the respondents' jealousy was negatively correlated with expected relationship stability, but their partners' reassurance was positively correlated with expected relationship stability. Prospective analyses showed no effect of respondents' jealousy on actual relationship stability, but positive effects of partners' reassurances and of partners' jealousy. These results seem more consistent with adaptive than destructive models of sexual jealousy.

Is the Influence of Single­Parent Families on Children Qualitatively

Different? A Behavior Genetics Analysis of the National Longitudinal

Study of Youth

Hobart H. Cleveland III and Richard P. Wiebe

Department of Family Studies

Department of Psychology

University of Arizona, Tucson, Arizona

Some investigators (e.g. Draper & Harpending, Belsky) have proposed that certain family structures, such as single parenthood, can trigger conditional life strategies in children developing thereunder. These, we believe, would be evinced by qualitatively different predictors of child outcomes in these families when compared with two­parent families. An alternate hypothesis holds that factors influencing development, including but not limited to the biological relatedness between the child and the caretakers and the amount of attention and monitoring afforded the children, influence children similarly regardless of family structure. These hypotheses were tested through examining genetic and environmental influences on intellectual abilities and behavior problems in whole and half siblings born to original participants in the National Longitudinal Study of Youth (NLSY), a national probability sample of over 11,000 respondents born between 1957 and 1964. Patterns of covariance were compared to determine whether a single multivariate model fit both single­ and two­parent families, or whether different models were needed.

The Biology And Culture Of Moral Systems

Kathryn Coe

Hispanic Research Center, Arizona State University

e­mail: icmck@ASUVM.INRE.ASU.EDU

In this paper I will examine existing data in light of Alexander's proposition that humans have one system of behavior codes and that that system is aimed at leveling reproductive opportunities. I will examine the earliest system of rules of behavior based on evidence found in modern hunter­ gatherers, as well as the system found in the early state. Attention is paid to the source of the system and the justification for it, the codes themselves, the presence or absence of an authoritative hierarchy that has the ability to use force or coercion, the boundary of the system, and the methods used to determine guilt, punish offenders, resolve conflicts, educate youth, and enact legislation.

It is argued that both kinship­based and state­based systems of behavior codes are based on religion; that is, they are based on the communicated acceptance of non­verifiable claims. An example of one such claim would be that the rules are of divine inspiration and that breaking them will bring about divine retribution. The acceptance of these supernatural claims has the significant effect of encouraging cooperation in the moral system.

Evolutionary Applied Psychology and the Workplace

Stephen M. Colarelli, Bradford Kruse, & Matthew J. Such

Department of Psychology

Central Michigan University

This paper examines the relationship between evolutionary principles and applied psychology, and it explores how an evolutionary applied psychology might be useful in the workplace. A principal goal of applied psychology is to use psychological knowledge to achieve intended effects. How might an evolutionary applied psychology be useful, given that evolution implies that change is (usually) slow, context­dependent, and difficult to predict? It would, first, require a different set of assumptions than traditional applied psychology. These would include: (1) the ecological nature of complex systems; (2) the role of variation, selection, and retention as a principal change mechanism in socio­cultural systems; and (3) the existence of content­specific psychological mechanisms that influence behavior. These assumptions suggest different, although perhaps more realistic, approaches for using psychological knowledge. One is the use of evolutionary algorithms and computer simulations to "grow"­­rather than design­­alternative organizational arrangements, based on different sets of inputs and goals. Another evolutionary approach is using variation as an intervention principle. Methods to increase or adjust variation­­and then allowing organizational selection and retention mechanisms work­­may be more useful than designing a priori solutions. A third approach is to use knowledge from evolutionary psychology. For example, given psychological mechanisms related to dominance, status, cooperation, and sexual behavior, an evolutionary applied psychology might suggest interventions that focus on organizational demographics (sex ratios, age distributions), group composition, and propinquity.

"Some Determinants Of Human Capital Achievement For The Children Of Albuquerque Men"

Benjamin Connor, Hillard Kaplan & Jane Lancaster

Dept Of Anthropology, University Of New Mexico

Albuquerque, Nm 87131­1086

Recent theoretical developments combining life history and economic optimality approaches (Kaplan, et.al. 1995) have led to the expectation that the impact of parental time investments on the rate at which a child acquires embodied human capital will be dependent on the parent's own levels of human capital. As a consequence more educated parents are expected to invest more time with their children than less educated parents. For a sample of 620 children of Albuquerque men it was found that paternal time investment, measured as the number of hours per week that the father spent with the child during preschool years, has a significant positive effect on the child's probability of graduating from high school. Maternal time investments, measured by the percent of time that the mother was employed in wage labor during the child's preschool years, has a similar effect. Both father's and mother's education levels also have a significant positive impact on the probability of high school graduation. The educational levels of both parents were expected to interact with their time investments, i.e. the more educated the parent, the greater the impact of their time investment on the child's probability of graduating from high school. Tests of this hypothesis gave mixed results.

The Epidemiology of Cultural Representations: Verse Forms in English Language Poetry

John Constable

Dept. of International Culture, Faculty of Integrated Human Studies, Kyoto University, Sakyo­ku, Kyoto, 606. Japan.

Fax: 075 753 6647. E­mail: john@ic.h.kyoto­u.ac.jp

No study of cultural materials which is predominantly evaluative, or critical, can be sufficiently technical to lead to consensus among researchers, and hence biologized criticism cannot be either an integrated part of human behavioural science, or a satisfying university subject. The theory of culture and cultural studies which offers the most promising alternative to critical interpretative and historical studies is Dan Sperber's program for cultural epidemiology, an approach which has the twin virtues of introducing population thinking into the study of culture, and of taking physicalism seriously. Following Sperber's lead this paper reports on a pilot study examining changes in the frequency of verse forms in English language poetry. The drift of high literary writers from restrictive forms to less restrictive forms, an aspect of verse which is discussed in detail, is explained in terms of the need of these writers to maintain the status of their production in the face of intense competition from an unrestricted form rising to dominance in the cultural pool, prose.

It is proposed that although apparently distant from evolutionary thinking, this mode of cultural study is not only compatible with evolutionarily grounded psychology, but is an extension of the general principles of darwinian theory.

Utopian Fiction and Human Nature

Brett Cooke

Modern & Classical Languages

Texas A&M University

College Station, TX 77843­4238

Utopian fictions provide a heretofore unstudied illustration of Alexander Argyros' dictum that literature is a society's means of choosing its future. Planning ahead would seem to be one of the major advantages of speculative thought, and art outstrips philosophical discourse to these ends by permitting one to vicariously live in an envisioned social order with a greater degree of fulsome experience. It allows us to visit utopia.

The past is highly relevant to such forward­looking inquiry. This is notable by how often the issue of human nature is relevant to utopian discourse, especially to the utopia/dystopia distinction. This study tests the hypothesis that fictional utopias will dictate behaviors similar to those attributed to the EEA. There is little point to social engineering if it does not make one feel better. Artists like More, Chernyshevsky and Bellamy accomplish this by reminding us of ancestral ways of life. On the other hand, there are two corollaries to dys­(or anti­) utopian fictions: these will affront human nature by depicting societies which require behaviors that either 1) affront established patterns or, 2) over­do them. Examples of food sharing, personal identity, social size, sexuality, and religious structures also will be provided from works by Huxley, Orwell and Zamyatin.

What Behavior Genetics Can Tell Us About Evolved Human Psychology

Leda Cosmides and John Tooby

Center for Evolutionary Psychology, CORI

University of California, Santa Barbara 93106

tooby@alishaw.ucsb.edu fax: 805 965­1163 phone: 805 893­8720

The study of the impact of genetic variation on behavior can be an important tool in exploring a range of questions that are central to an evolutionary understanding of humans. Perhaps the most interesting and underutilized application is how behavior genetics may be used to explore human species­typical psychological architecture. In particular, the continuous injection of new mutations and the background presence of genetic noise provide natural diagnostic probes, much like strokes or head trauma are presently used in cognitive neuroscience. Mutations in the genetic specification of complex psychological adaptations are expected to cause impairments that may help reveal the evolved functional architecture of cognitive specializations in normal unimpaired individuals. This emerging cognitive genetics offers alternatives to the study of individuals with ontogenetically caused neural impairments, because physically caused neural damage has no intrinsic tendency to follow functional boundaries, while a subset of mutationally introduced variation may. In contrast, the methods presently available in behavior genetics allow almost no conclusions to be made about the sources of intergroup differences in quantitative behavioral characters, or about how responsive novel or unstudied environmental interventions may be in changing the expressed phenotype along socially targeted dimensions.

WHEN IN ROME...A Small Scale Test Of Boyd and Richerson's Conformist Transmission Model

Julie Coultas

School of Cognitive and Computing Sciences

University of Sussex

U.K.

Some imitative behaviour in humans is spontaneous and is produced through a predisposition to imitate the most common behaviour. This behaviour is more likely to be elicited if an individual is naive and in an uncertain environment. A small scale test of Boyd and Richerson's (1985, 1991) conformist transmission model was undertaken using 105 first year psychology undergraduates (separated into 8 groups) in their first ever computer practical class. A normally, rare behaviour was modelled by a number of (unknowing) stooges. As each subject entered the laboratory the proportion of others modelling the rare behaviour was noted and the behaviour of the newcomer was recorded. Logistic regression indicated that proportion of individuals modelling the rare behaviour was a significant predictor of imitation. Thirty one per cent of subjects imitated the behaviour when the initial group size was five. No subject imitated the behaviour when initial group size was three and no subject imitated the behaviour when the proportion producing the behaviour was less than seventy one per cent. Phenomena such as this are discussed in terms of their contribution to an explanation of human cooperative behaviour.

Heroic Literature as Aggression Control Mechanism:

Theoretical Prolegomena and a Pilot Experiment

Gary Cox

Foreign Languages & Literatures (Russian)

Southern Methodist University, Dallas, Texas 75275

(214) 768­2294, fax: (214) 768­3341, e­mail: gcox@post.smu.edu

It is hypothesized that a group's recorded aggressive fantasies constitute a mechanism for regulating levels of aggression. The recent 4­university study on televised violence distinguishes between aggression­inhibiting motifs and aggression­enhancing ones, giving us a valuable experimental instrument.

Further study requires a theoretical stance on the interface between physiological components (impulses) and cultural components (constructs) of behavioral responses to fantasy aggression. Culturally transmitted data are constructs, but they are constructs of something (construe is a transitive verb); what is construed is an impulse, triggered physiologically or environmentally. Genetically conditioned aggressive impulses may be "domain­specific modules." The phenotype or group construes the impulse in accord with self­defined proximate needs, ignorant of its genetic goal (selective reproductive fitness). Inherited neural structures may be "exploited" by culture in ways divergent from, or opposed to, the selective advantages that stimulated their evolution (e.g., status competition among monks; e.g., mooning). Fantasy ability (i.e., literature) may have evolved, through mimesis, as a device for enhancing "exploitative construction" of hard­wired impulses.

As a pilot experiment, rates of aggression­inhibiting and aggression­enhancing motifs are contrasted in 3 representative bodies of oral and written literature: Yanomamo folklore, Russian folklore, and chivalric romances. Hypothesis tentatively confirmed.

Dominance Hierarchies and The Evolution of Reasoning

Denise Dellarosa Cummins

Cognitive Science

University of Arizona

Tucson, AZ 85721

There is a good deal of evidence from primatology and evolutionary anthropology that the most pressing reasoning problems primates faced during their evolution were of a social nature. The most crucial of these falls under the category of deontic reasoning, that is, reasoning about what is permitted, obligated, or prohibited. As a simple example, avoiding agonistic encounters and ostracism requires reasoning effectively about the permission structure inherent in primate dominance hierarchies (i.e., who may groom, play, and mate with whom). Acquiring and maintaining status within the hierarchies depends on forming and maintaining alliances based on reciprocal obligations. My thesis is that problems like these occurred so frequently and with such adaptively important consequences that domain­specific reasoning modules evolved for solving them. In support of this, I present evidence that, unlike other types of logical reasoning, deontic reasoning emerges early in human development, is dissociable from other types of intelligent reasoning at the neurological level, and is apparent in the reasoning of protocols of adults regardless of culture and educational background.

Three Lessons of Biology for Psychology:

The Adapted Mind, Within­Organism Selection, and Perceptual Control Theory

Gary Cziko

University of Illinois at Urbana­Champaign

Biology provides three important lessons for understanding human behavior. The first is that the human mind is a product of the human brain which is the result of natural selection. The second lesson is the evolution of evolution, i.e., _among_­organism variation and selection has resulted in the evolution of mechanisms of _within_­organism variation and selection, as is the case for the immune system's production of antibodies, brain development, and aspects of cognition. Through within­organism cognitive variation and selection, the adapted mind becomes an adapt_ive_ mind. The third lesson is that organisms have evolved negative­feedback control systems to regulate not only their internal environments ("homeostasis") but also aspects of their external environment, resulting in what we observe as purposeful, functional behavior. While the first of biology's three lessons is well accepted by evolutionary psychologists, the other two are not. Arguments based on both theory and research will be made for the importance of biology's second and third lessons, going beyond the development in my _Without Miracles_ (1995, MIT Press). Also, a computer simulation will be shown demonstrating how the interaction of negative­feedback perceptual control systems accounts for imprinting behavior in birds and human collective behavior.

HOW TO DISTINGUISH EXAPTATIONS FROM ADAPTATIONS IN EVOLUTIONARY PSYCHOLYGY?

Austin Warren Dacey

Bowling Green State University

Evolutionary or Darwinian psychology holds human psychology to be largely a collection of adaptations. Contrary to this, Gould has suggested that human psychology is largely a collection of EXAPTATIONS, or structures currently put to a use other than that which they were selected for. If he is right, then evolutionary psychology would be left with not much to talk about. It contends that many important features of human psychology are best explained by the theory of natural selection. But exaptations cannot be so explained, since their present features are not the product of selection for those features.

This essay addresses not the crucial question of whether the mind is mostly a collection of exaptations or adaptations, but rather the prior question of how to distinguish the two in evolutionary psychological explanantion. I begin by elaborating on the invention and use of the concept 'exaptation' in biology, and introducing several terminological distinctions to improve its application. Second, I indicate two general difficulties with the application of the concept, one of which appears in Gould's analysis. Third, I examine a method of distinguishing exaptations from adaptations­­ recently emphasized by Pinker and Bloom­­ by which one recognizes an exaptation by its deployment of complex and specialized problem­solving machinery in a task that does not require such complexity or specialization. I conclude that because of some interesting complications, this is not a good method for evolutionary psychological explanation. Finally, I point to a method that is more promising.

I suspect that the possibility of exaptation does not mean the cancellation of the research program of Darwinian psychology, but rather its further refinement and progress. I am hopeful that close analysis of the concept of exaptation will be a contribution to that end.

EVOLUTIONARY PSYCHOLOGY OF KINSHIP: A PROMISSORY NOTE

Martin Daly, Catherine Salmon and Margo Wilson

Dept. of Psychology, McMaster University, Hamilton, Ont. L8S 4K1

Daly@McMaster.CA

Kinship is the central construct in evolutionary biological analyses of social phenomena and kinship is also central to anthropological analyses of social phenomena as well. Since kinship is so important both theoretically and phenomenologically, one might suppose that it would have attained a central position in social psychology, too, but alas it has been virtually ignored. What has yet to be appreciated by psychologists and other social scientists who lack a selectionist perspective is that different classes of social relationships are qualitatively distinct in many specific ways rather than just in their degrees of intimacy.

Human kinship systems are dauntingly diverse, but they have many universal aspects. We shall consider 13 putative universals of human kinship psychology which suggest that our species possesses a complex evolved system of kinship cognition adapted to the task of nepotistic decision­making.

An Evolutionary Theory of the Human Family

Jennifer Davis and Martin Daly

Department of Psychology

McMaster University

Hamilton, Ontario

davisjn@mcmaster.ca

Emlen's recent paper "An evolutionary theory of the family" (PNAC, 1995) provides a valuable summary of existing theories about the nature of family systems and the reasons why they have evolved in certain species. Emlen's theoretical account leads him to propose 15 predictions about how family systems function, and he reviews evidence in their favor. Elucidation of the evolved psychological mechanisms that govern human reproductive decisions and consideration of unusual aspects of human sociality may help explain the deviation of available data from the predictions, as they are currently worded, and provide insight into how to better apply them to human family systems.

Parental Investment: "When Mom Can Provide Resources"

Jack Demarest and Megan Schramm

Monmouth University, Department of Psychology

West Long Branch, NJ 07764

We examined differences in perceived levels of parental investment by husbands and wives as a function of the wife's ability to provide resources (occupational status) and the age of their offspring. 46 couples indicated how much time per week each parent spent on various parental investment activities, including time at work outside the home; time devoted to nurturing the child; playing with the child; ensuring child's safety; educating the child; and custodial care. The proportion of income each parent provided was also calculated. As expected, men provided more investment in time at work outside the home, and in financial contributions; women invested more in every other category. Wives who provided the most resources (high occupational status) and who had a young child (less than 3 yrs old) exhibited greater overall parental investment than all others. In fact, they spent as much time on direct child care as homemakers and females with low occupational status. Husbands did not significantly vary their investment of time as a function of the wife's ability to provide resources.

Group Selection Inferred From Breast Asymmetry Of Playboy Centerfold Twins

Patrick Dempsey

Unaffiliated, 5091 Citation, Cypress Ca 90630

Playboy has an archive of many millions of unpublished Centerfold photographs. Often, these are published, un­retouched in special Playboy Newsstand Editions. From these un­retouched photos we have discovered roughly a 20% asymmetry rate in centerfold areolas, including asymmetry reversals in four sets of Playboy twins. These rates are roughly similar to percentages found by others who propose a "Bad Genes" concept for human breast asymmetry. We review the evolution of primate secondary sex characters leading to asymmetry in human bread, breast baldness in percentages consistent to that of left handers in all­star baseball teams and common in human brain physiology. Some argue genetic noise accounts for variation of human physical attraction. We propose that human asymmetry may be evidence of a "Group Phenotype" an artifact of group selection, rather than a sign of parasite load. We argue that brain and breast asymmetry are most likely linked by an as yet undiscovered developmental process common to both. That developmental hormones working to create asymmetries in the human brain sometimes spill over to cause asymmetry in the human breast. We propose that the most likely generator of this adaptive "Group Phenotype" are the newly discovered Dynamic mutations or trinucleotide repeats responsible for rare neurodegenerative disorders such as Huntington's Disease and others.

Protocultural Aptitudes In Early Mother­Infant Interaction

Ellen Dissanayake

c/o Franzen, 180 Colman Drive

Port Townsend, WA 98368

The close mother­infant relationship is characteristic in primates, and especially in humans where infants are highly altricial. In most if not all human societies, ritualized face­to­face play between mothers and infants ­­ using facial, vocal, and kinesic signals ­­ provides significant neurological, emotional, intellectual, linguistic, and psychosocial developmental benefits for infants. Organized in jointly­maintained temporal patterns with simultaneous or overlapping (coactive) and alternating (turn­taking) sequences to which both partners respond in split­seconds, these signals also correspond to universal expressive features indicative of motivation for social contact (affiliation) found in nonverbal communication in adults, rudiments of which are observed in mother­infant and other dyadic behaviors in some primates. It will be suggested that the sensitivities and competencies evolved by human infants and mothers that enable them to participate in these early interactions not only contributed ancestrally to infant survivorship and enculturability, as is well accepted, but may also underlie the origins of some human cultural behaviors.

Jealousy As A Function Of Rival Characteristics.

Pieternel Dykstra & Bram P. Buunk

University of Groningen, The Netherlands

According to evolutionary psychology men and women differ in the characteristics they value in a partner. Men value physical attractiveness in women since a woman's physical attractiveness is related to her fertility while women value dominance in men since dominance is related to a man's ability to provide resources. Since jealousy is evoked by characteristics of the rival that are perceived to be important to the other sex, it was predicted that jealousy in males would be influenced by the rival's dominance while jealousy in females would be influenced by the rival's physical attractiveness. In an experiment participants were presented with a scenario in which their current (real or imagined) partner was flirting with an opposite­sex individual. Next, participants received one of four profiles of the individual flirting with their partner. Profiles consisted of a photograph (low or high in attractiveness) and a personality description (low or high in dominance). Consistent with an evolutionary model of jealousy, females exposed to physically attractive rivals reported more jealousy than females exposed to average attractive rivals. Males exposed to physically atractive, compared with average attractive, rivals did not report more jealousy. Males exposed to rivals high in dominance reported more jealousy then males exposed to rivals low in dominance, while females exposed to rivals high in dominance, compared with rivals low in dominance, did not report more jealousy.

Individual Actors and Systems­Level Effects

Rada Dyson­Hudson and Dominique Meekers

Department of Anthropology, Binghamton University, New York

Sociology/PRI, Pennsylvania State University

Life histories of more than 11,000 South Turkana pastoralists were recorded, including sectional affiliation, year birth, and (where relevant) year marriage, year death, year migration, and reasons for migration. The sample is (as nearly as possible) all the descendants, living and dead, male and female, pastoralist and non­pastoralist, of 63 South Turkana elders born between 1860 and 1917. Information about wives of the male members of each genealogy was also collected. The data allow an analysis of migration across ecosystem boundaries in the context of the uterine and polygynous family; allow retrospective longitudinal analysis of migration across ecosystem boundaries for an approximately 90 year time span, and provide information on the relationship between individual behavior and the "functioning" of the ecosystem. They show that, although decisions about leaving the pastoral sector are made by individual South Turkana pastoralists seeking alternative sources of economic support, the net effect of these individual decisions on the ecosystem is toward regulating population with respect to resources.

Comparing the Sexes: Feminism, Science, and Interpretation

Alice H. Eagly

Northwestern University

Comparing the sexes is a research activity that offers many scientific and ideological challenges. Feminist discourse, in particular, often trades on claims about the presence or absence of differences between the sexes. To place the study of sex­related differences and similarities on a better scientific footing, psychologists have turned to quantitative synthesis as a method for integrating research findings across studies. The method is especially informative for examining sex­related differences because the large numbers of psychological studies that have compared female and male behavior render generalizations based on narrative reviewing especially unreliable. These meta­analyses have provided a more scientifically adequate database, but they do not yield interpretations. Although evolutionary psychology provides a framework for interpreting certain sex­related differences in behavior, alternative social psychological frameworks provide equally powerful frameworks. In particular, social role theory maintains that sex­related differences are influenced by gender role expectations that are derived from the specific family and occupational roles that women and men occupy in the society. Over time, women's and men's roles change as the economy evolves, and these gender roles slowly change. In contemporary post­industrial societies, men's and women's roles have become somewhat more similar as the majority of women have entered paid employment. Nonetheless, social role theory predicts only modest erosion of sex differences, because occupations remain moderately sex­segregated with women concentrated in occupations believed to require feminine attributes and men concentrated in occupations believed to require masculine attributes. In addition, domestic work is carried out mainly by women, and women remain moderately economically dependent on men.

Human Breats Disguise Fertility And Mensuration Signals It Occurence.

Dorothy Einon.

Psychology Department, University College London, Gower Street, London, WC1E 6BT

Alexander & Nooman (1979) suggest that hiding of oestrus and constant receptivity in women evolved to induce men to parent. By themsleves such mechanisms are insufficient to induce male parenting. Men who locate women experiencing ovulatory cycles have a 1:14 chance of meeting fertile woman. Odds which are not dissimilar to males of species who share fertile females with a large number males. The interval between births in women is divided into three phases: pregnancy, lactation, and waiting time. Women only ovulate in the later. To induce men to commit women must hide both ovulation and lactation amenorrhea. It is suggested that the growth of breasts at puberty are an effective means of doing this. It is further suggested that mensuration acts as a signal for the onset of fertile cycles, but that such signals are only available to men who stay with women. Low fertility and high rates of spontaneous abortion maintain that commitment over time because the odds of finding a woman mensturating are always higher inside the relationship than outside.

Alexander R.D. & Nooman, K.B. Concealment of ovulation, paternal care and human social evolution. Evolutionary Biology and Human Social Behavior, N.A. Chagnon and W. Irons. Duxbury Press, North Scituate, MA. 1979.

The Dating Alternatives Questionnaire: An Evolutionary Approach to Comparison Level for Alternatives

Bruce J. Ellis

Psychology Department, Sloan Hall 235, Central Michigan University,

Mt. Pleasant, MI 48859

From an evolutionary perspective, one's "mate value" is a function of the degree to which one possesses attributes that reliably correlated with the capacity to promote reproductive success in members of the other sex in ancestral environments. From a social exchange perspective, one's "market value" as a mate is a function of the degree to which one possesses whatever attributes are valued by the other sex in one's culture. Both evolutionary and social exchange theorists emphasize that individuals make social comparisons between self and others and use these comparisons to form concepts about one's own value as a mate. Social exchange theorists have developed social comparison measures to assess individuals' global perceptions of relative market value within dyadic relationships. In two studies of dating couples (N = 227 heterosexual dyads), the present research develops social comparison measures to assess individuals' specific perceptions of relative mate value within dyadic relationships. These content­specific measures are based on strategic modeling of specific adaptive problems encountered in mating relationships throughout our evolutionary history. Compared to the past global measures, these content­specific measures significantly increase our ability to predict feelings of love for one's dating partner and investment of time in one's dating relationship.

Social Hierarchies And Reproductive Success At The Individual And Group Levels

Lee Ellis

Minot State University

ellis@warp6.cs.misu.nodak.edu

This paper will extend a recent review of the literature on relationships between dominance in nonhuman animals and reproductive success (Ellis, 1995) by exploring theoretical issues surrounding the relationship between all types of social hierarchies (including human social status) and reproductive success. I will argue that most animals who form social hierarchies may realize a reproductive benefit at both an individual and group level. While those highest in the social hierarchy are expected to usually derive greater reproductive benefit than those who are lowest in the hierarchy, there are conditions under which this should not be true.(97 words)

Evolutionary Studies Of Animal Families: What Can They Tell Us About Ourselves?

Dr. Stephen T. Emlen

Jacob Gould Schurman Professor

Section of Neurobiology and Behavior Cornell University

Ithaca, New York 14853­2702

E­mail: ste1@cornell.edu

Phone: (607) 254­4327

Fax: (607) 254­4308

Darwinian thinking is making important inroads into the social sciences. This is exemplified by the growing discipline of Evolutionary Psychology, which attempts to understand human behavior by positing that many of our social behaviors and emotions represent heritable adaptations that were selectively advantageous for life in our ancestral (pre­agricultural, pre­industrial) human environment.

This evolutionary framework for viewing behavior, in turn, derives from Behavioral Ecology, the discipline that studies the adaptive bases of animal social behaviors. I will review some of the basic assumptions of Behavioral Ecology, discuss the importance of animals as model systems, and review general patterns of family dynamics that occur in non­human species. I will argue that an evolutionary theory of the family is at hand, and that we can learn much about ourselves by examining our own family dynamics within this evolutionary framework.

Cross­sex Differences in Incest: Towards an Evolutionary Explanation of

Patterns in Myth and Incidence

Daniel M.T. Fessler

Dept. of Anthropology, University of California San Diego

9500 Gilman Dr., La Jolla, CA 92093­0532

email dfessler@weber.ucsd.edu

Although myths containing Oedipal themes have been identified in many cultures, stories concerning the Electra configuration are rare. In contrast, father­daughter incest appears to be more common than mother­son incest. These two patterns reflect fundamental differences between male and female sexuality. Psychoanalytic accounts of the Oedipus and Electra complexes do not adequately explain differences between the sexes. Moreover, these approaches focus on the young child as a sexual actor, yet it is the older child who constitutes a realistic rival for the same­sex parent. In contrast, both cultural anthropologists and evolutionary psychologists focus not on sexual rivalry, but on the conflict over resources which occurs between parent and child. Evolutionary psychologists have also explored father­daughter incest as a case of conflicting reproductive strategies. However, the emphasis of these explanations is misplaced. Rather, parent­child incest is best viewed as a special kind of adultery. Because parental investment differs across the sexes, there are significant differences in reactions to adultery. Likewise, because the reproductive concerns of men and women differ, mother­son incest is a significant threat to fathers, but father­daughter incest is far less threatening to mothers, and may even be advantageous sometimes.

Rationality As An Adaptive Adaptation

James H. Fetzer

Department of Philosophy

University of Minnesota

Duluth, MN 55812

The relationship between causality and rationality assumes an acute form from the perspective of evolution, since natural selection appears to be a causal process that functions independently of considerations of rationality. Once distinctions have been drawn between rationality of belief and rationality of action­­neither of which has to be conscious to organism or agent­­it becomes obvious that rationality of both kinds promotes attainment of goals, which is significant to evolution when those goals include survival and reproduction. Indeed, given these goals, behaviors that are adaptive are rational and be­ haviors that are rational are adaptive. Rationality is especially useful in coping with genetic lag. The emergence of mentality thus provides a means toward the end of acquiring more efficient, effective, and reliable mechan­ isms to serve this function. Relative to the evolution of species, natural selection is a causal process yielding rationality as an adaptive adaptation.

By Accident, or By Design.

Larry Fiddick, Leda Cosmides, and John Tooby

Dept. of Psychology, Dept. Of Psychology, Dept. of Anthropology

University of California, Santa Barbara

It has been suggested that one of the design features of a psychological mechanism for detecting cheaters is that it distinguishes between intentional and accidental violations of a social contract. A 'look for cheaters' program should be activated only in those cases where individuals stand to illicitly benefit by violating rules and it should not be activated when a person accidentally breaking the rule does not stand to receive an illicit benefit. Experimental evidence demonstrating that people do make such a distinction has lent support to the view that cheater detection is governed by a special­purpose, cognitive mechanism.

However, psychological experiments on reasoning demonstrating that people are able to detect violations of rules other than social contracts, such as precautions, has been taken as undermining claims for the specialized nature of the underlying cognitive mechanisms. The possibility remains that there is a variety of specialized mechanisms. Were this the case, evolutionary arguments would suggest that social contract mechanisms and precaution mechanisms should diverge in terms of sensitivity to accidental violations. Whether one intentionally or accidentally violates a precautionary rule is irrelevant since any violation puts the violator in danger. We present evidence demonstrating that whether or not the violation of the rule was accidental influences the inferences people draw about social contracts, but not precautions, on formally identical cognitive tasks.

Daughters Of El Cid: Family Deterrrence Of Domestic Violence In Spain

Aurelio Jose Figueredo, Karen Bachar, and Janine Goldman­Pach

Behavioral Evolution And Development Group, University of Arizona

A telephone survey of battered and non­battered women with children under 12 years old was conducted in Madrid, Spain. This cross­national constructive replication was supported by a BRAVO/MIRT Grant (5T 37 TW00036) to Jose Ribeiro from the NIH Fogarty International Center. Four different subpopulations were sampled for varying degrees of risk to test if a woman's extended kin network protected her against spousal abuse. Three factors had previously predicted domestic violence in a Tucson, Arizona, study: (1) Sex, (2) Money, and (3) Paternity; a general factor for domestic violence included four subscales: (1) Verbal, (2) Physical, (3) Escalated, and (4) Sexual. The spatial distributions of the woman's relatives were weighted by their coefficients of relatedness; family support was also measured. A path analysis estimated the direct and indirect effects of the woman's kin on domestic violence. Kin densities both inside and outside Madrid were found to reduce domestic violence, although kin densities outside Madrid exerted lesser effects. Because higher kin densities inside Madrid predicted lower kin densities outside Madrid, the major difference was in family spatial distribution rather than absolute family size. Because these effects were not mediated by reported family support, the protective effects of extended kin networks were attributable to deterrence rather than support.

Family Environment, Stress Response, and Health Among Children in a Caribean Village

Mark Flinn, Mark Turner, & Barry England

U Missouri, Northwestern U, & U Michigan Hospitals

We investigate daily variations in glucocorticoid stress response, immune function, and health among children in a natural (non­clinical) environment. The study involves 262 children aged one month ­ 18 years residing in a rural village on the east coast of Dominica. Fieldwork was conducted over a nine­year period (1988­1996). Research methods and techniques include: immunoassay of saliva samples (N = 24,560), systematic behavioral observations, psychological questionnaires, health evaluations, medical records, informal interviews, and participant observation.

Analyses of data indicate that childhood stress is associated with family environment. Children residing with caretakers that are nonrelative, stepparents, or single parents without kin support have different cortisol profiles than children living in nuclear, extended, or single parent with kin households. Temporal changes in family relationships are accompanied by elevated cortisol levels. Children with histories of troubled family relationships during infancy commonly have unusual cortisol response profiles.

Stress is associated with child health. Children with higher average cortisol levels have more frequent health problems than children with lower cortisol levels. Temporal patterns of cortisol suggest that children undergoing stressful events are at higher risk for illness (diarrhea, influenza, common cold, asthma, rashes, etc.) during a two ­ six day period following unusually high cortisol levels. Concomitant with abnormal cortisol response is altered immune function; some chronically stressed children appear to have reduced cell­mediated (neopterin, microgloblin 2), humoral (s­immunoglobulin A), and/or non­specific (neutrophil recruitment via interleukin­8) immunity.

These results suggest that family environment has important effects on childhood stress, health, and psychological development. The mind of the human child appears especially sensitive to interactions with caretakers. Glucocorticoid stress response to family trauma appears to allocate somatic resources to mental function and protection from auto­immunity.

Supported by NSF BNS 8920569, NSF SBR 9205373, and NIH RR 07053 to MVF.

Neurohumoral Brain Dynamics Of Group Formation

Walter J Freeman

Department of Molecular and Cell Biology

University of California, Berkeley CA 94720

wfreeman@garnet.berkeley.edu

The biological basis of consciousness can be explored with two assumptions: that animals are conscious in ways less complex than in humans, and that neural mechanisms are the substrate of mental processes. My main concern here is with a salient property of consciousness, namely the solipsistic isolation between different brains. How is it that we cannot be certain, by direct experience, what any other entity has in its consciousness, whether it is an animal, a machine, or a fellow human being? Research on brain waves (EEG) offers a mechanistic answer to this fundamental epistemological question. It is because brains are self­organizing systems that are closed with respect to meaning. This is shown by following the flow of sensory input into the olfactory, visual, auditory, and somesthetic systems and finding that input is replaced by spatial patterns of neural activity, which are uniquely constructed by brains as meanings. The question then follows: how do humans surmount the resulting solipsistic isolation and engage in social action based in mutual understanding? A proposed answer is that human brains already contain mammalian neurohumoral mechanisms for pair bonding, and that these have been adapted through biological and cultural evolution to individual, familial, tribal, religious and political conversion processes. (204 words)

A Biological Basis for Group Mind without Group Awareness

Walter J Freeman

Department of Molecular & Cell Biology

University of California at Berkeley

The concept of 'group mind' has been derived from observation and analysis of cooperative behavior through sociology and anthropology, so that its biological basis is unclear. In particular, the question arises, whether the property of awareness can be assigned to groups in something like the way that it is conceived for individual minds, as, for example, to the pygmies of Central Africa (Arom 1991), who cannot explain how they make their communal music together. Neurophysiological explorations by Libet (1994) and his colleagues have shown that the complex integrative process, which results in awareness of a stimulus, requires about half a second, although the time of stimulus onset is back­dated close to its origin. Evidence for a comparable delay has been found for awareness following the genesis of self­paced actions. A hypothesis is presented here that socialization leading to group actions depends on a neurohumoral mechanism for 'unlearning', which has evolved from a mammalian process supporting reproductive behavior, and which enables inculcation of cooperative maternal/paternal activities. The implication is that human socialization through unlearning gives a basis for preconscious actions embedded in past learning, such that the rapid exchange of behavioral signals during cooperation can result in group intentional behaviors without the necessity or opportunity for individual reflection. Introspection can interfere with the smoothness of group actions and, in any case, would appear always to follow the actions through elective individual processes of contemplative evaluation.

References

Arom, Simha (1991) African polyphony and polyrhythm: musical structure and methodology. Translated from French by Martin Thom, Barbara Tuckett, Raymond Boyd. Cambridge UK: Cambridge University Press.

Freeman WJ (1995) Societies of Brains. A Study in the Neuroscience of Love and Hate. Hillsdale NJ: Lawrence Erlbaum Associates.

Libet B (1994) Neurophysiology of Consciousness: Selected Papers and New Essays. Boston MA: Birkhauser.

Towards an Understanding of Human Skin Color in the EEA: Age­Related and

Sex­Related Meanings

Peter Frost

Department of Anthropology

Universite Laval

Male skin has more melanin and hemoglobin than does female skin, i.e., men are browner and ruddier; women, paler. The sexes differ in both "constitutive" pigmentation and "facultative" tanning potential. This sex difference begins at puberty when girls lighten in color; it may widen in adulthood as male constitutive pigmentation darkens in response to repeated tanning.

Within ancestral societies, i.e., bands of related families, the different complexions of men and women were the main source of skin color variability. Darker skin signified "man" and lighter skin "woman" (or "infant"© ­­­important information in band societies, where age and sex were the main social cleavages. Early humans may have thus prepared themselves for potential social interactions by using complexion and other visual cues to identify the type of encounter they might have to face (man­woman, man­man, woman­woman, or adult­infant) and adopting the appropriate state of readiness.

Over time, "hardwired" mental linkages may have formed between this visual cue, the type of encounter it called to mind, and the appropriate state of readiness.

"Footedness" in Parrots

Dr. Mildred Funk

Biology Department, Roosevelt University, Chicago

Through several centuries, published reports have claimed "footedness" in parrot species, suggesting that parrots have population preferences in limb use similar to human handedness. However, early parrot studies did not include many species, used small samples and took few observations of those individuals. More recently, several studies of parrots have found a left­footed tendency in 25­30 species and a right footed bias in several species of one genus, the Australian Rosella. This presentation briefly reviews the parrot literature and presents data on a species closely related to the Rosella, the New Zealand parakeet (Cyanoramphus auriceps). Of 13 birds tested, nine were right­footed, two were left­footed, and two used both feet equally in feeding behaviors. This right claw bias may be related to their ecological activities. This is a small sample and more subjects are being sought.

Variation in Developmental Imprecision: Implications for Evolutionary Psychology

Steven W. Gangestad

Department of Psychology

University of New Mexico

Albuquerque, NM 87131

sgangest@unm.edu

During the 1950s, Waddington, Lerner, Thoday, and others argued that selection should favor genetic properties (e.g., coadaptation, modifiers) that ensure developmental stability ­­ the precise expression of developmental design in the face of genetic and environmental perturbations (e.g., mutations, pathogens). These phenomena have received limited attention from behavior geneticists and evolutionary psychologists. This talk addresses several topics: 1) Evidence that neurodevelopmental disorders are partly a function of developmental instability; 2) Evidence that, even in nonpathological populations, variation in developmental instability affecting brain structure and function is present; 3) Reasons why selection has not driven out variation in developmental stability; 4) Implications of these issues for a major tension between behavior genetics and evolutionary psychology, namely, a universal design purported to exist despite substantial genetic variation in psychological phenotypes.

Invoking Alpha State to Treat Involuntary Subordinate Strategy

Russell Gardner, Jr., M.D.

Department of Psychiatry and Behavioral Sciences

University of Texas Medical Branch

Galveston, TX 77555­0428

Are there implications for considering depression not as a biochemical imbalance but as a brain­encoded result of natural selection? Animal model research suggests that depression may reflect an involuntary subordinate communicational strategy that had existed in animals ancestral to humans, involuntary as it occurs outside conscious control, subordinate and communicational because the characteristic behaviors communicate lack of threat, and a strategy in that the communicational state was "designed" by Darwinian selection. Other work concerns mania as a maladaptive also involuntary variant of a communicational state in which the individual signals "taking charge" as through possessing alpha status in a hierarchy. Use of serotonin­enhancing agents not only reverses depression in humans but elevates status in subordinate vervet monkeys. Case reports show that patients appropriately feel more "in charge" with serotonergic medications, although changes in actual status are less evident. Nonhuman/human contrasts may assist in intervention: large­brained humans have metaphoric capacities that allow one to be voluntarily "in charge" of life components. The shiver/ATP strategy therapeutically deploying this formulation uses shivering to illustrate ancient involuntary strategies. Humans more uniquely than other animals are able to use Allies in deploying Thought to analyze circumstances and capably Plan in order to forestall future problems.

Superior Spatial Memory of Women: Stronger Evidence for the Gathering Hypothesis.

Steven Gaulin, Donald McBurney, Trishul Devineni, and Christine Adams.

Department of Anthropology, and Department of Psychology, University of Pittsburgh.

Male and female college students played the commercial game Memory requiring them to recall the locations of previously viewed items, and also completed the 20­item mental rotations task. As is typical, males performed better than females (d=.67) on the mental rotations task. In contrast, females outperformed males by a large margin (d=.89) on the memory task. Performance on the two tasks was positively correlated for females but not for males. The reversal of the sex difference between the tasks suggests that spatial ability is not a unitary trait and that different kinds of spatial processing may have been important for males and females in the EEA. The Memory game appears to mimic the cognitive demands of foraging better that previous "spatial" memory tasks.

GROUP SELECTION: IT HAPPENS (IN HUMANS)

Francisco Gil­White

U.C.L.A.

Sound arguments have been made against the likelihood of group selection being an important force in non­human populations. These arguments, however, fail to apply to group selection amongst cybernetic (self­regulating) cultural units. This is because cultural cybernetics operates through conformist transmission (CT) and third­party punishment (3PP) to keep the frequency of certain memes (ideational or behavioral variants) at high frequency. These mechanisms are important because of their effects on migrants. If a migrant with a new meme enters a population, CT and 3PP will act to disfavor that meme, and therefore migration will often not lead to the rapid diminution of memic variation between groups that would make group selection of memes implausible. Group selection at the memic level will sometimes lead to the emergence of genetic adaptations because the cultural environment creates genetic selection pressures on group­living individuals. This still argues for species­wide genetic adaptations (in cases where the meme is stable enough and it is advantageous to hard­wire the meme), however, because selection amongst groups entails that ultimately all groups end up with such a stable meme, generating selection pressure across the species for geneti