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HBES 2005 Presentation Abstracts Cooperative courtship: Facilitating flirtation with friends Mate selection researchers have traditionally construed same-sex conspecifics as playing a competitive role in the process of attracting a mate. However, mate acquisition can also be thought of as a complex cooperative game involving interdependent groups who facilitate the sex-specific goals of their members. Here, a model is presented which differentiates the mate acquisition goals of males and females and suggests contexts in which cooperative strategies are likely to emerge. Under the cooperative courtship model, females are predicted to primarily use their groups in order to: (1) raise thresholds for male investment, and (2) construct barriers to unwanted romantic advances. Males, on the other hand, are predicted to primarily use their groups to: (1) meet female thresholds by appearing more socially desirable, and (2) break down barriers in order to achieve romantic access. Findings from three studies were consistent with the cooperative courtship model. Contact information: Department of Psychology Ritual, Emotion, and Sacred Symbols: The Evolution of Religion as an Adaptive Complex This presentation considers religion as a unique human adaptation growing out of non-human ritualized display but diverging from such display through the emergence of four novel components. These components include: music-based communal ritual, separation of the sacred and the profane, belief systems incorporating supernatural agents and counterintuitive concepts, and the importance of adolescence as a preferred developmental period for religious transmission. We consider the critical element differentiating religious from non-human ritual to be the conditioned association of emotion and abstract symbols. Neurophysiological mechanisms underlying such associations are proposed. We argue that the brain plasticity of human adolescence constitutes an "experience expectant" developmental period for ritual conditioning of sacred symbols, and we suggest that such symbols evolved to solve an ecological problem by extending communication and coordination of social relations across time and space. Contact information: University of Connecticut The Relationship of Psychological Symptoms (Anxiety, Depression, and Eating Concerns), and Mating Strategies and Current Relationship Attachment Evolutionary approaches propose that depressive and anxiety symptoms result from adaptive mechanisms facilitating survival. Eating disordered symptoms are viewed as adaptive mechanisms maladaptively triggered by sociocultural contexts idealizing a biologically inappropriate female form. The current study explored symptoms of anxiety, depression, eating disorders and mating strategies and current relationship attachment (N=274). After controlling for age, romantic relationship status, and virginity status, eating concerns were strongly and specifically associated with less restrictive sociosexual styles and greater lifetime number of sexual partners. Within romantic and non-romantic relationships, increases in both eating concerns and depressive symptoms were associated with increased fears of rejection and abandonment. Independent of the experience of psychological symptoms, greater levels of discomfort with closeness and depending upon others in both romantic and non-romantic relationships were associated with a less restrictive sociosexual style. Anxiety was correlated with eating concerns and depressive symptoms, but not significantly associated with other variables measured. Contact information: Department of Psychology Disturbances in the Dreamtime: Evidence for Prehistoric Violence in Subarctic Dene Traditional Oral Narratives Oral narratives have been employed by traditional indigenous peoples the world over for millennia. The action in such narratives most often occurs in a liminal time known as the Dreamtime, a time that is not necessarily somewhere in the lineal past but, according to some traditional indigenes, can be here-and-now if we use narratives properly and dream them. Ubiquitous motifs about an ambivalence between ethnocentrism, xenophobia, violent acts towards strangers and revenge raids against enemies, and on the other hand marriages and exchanges between strangers who are often represented as animals can be found in the Dreamtime narratives of most indigenous hunters and gatherers. Embedded in these narratives are universal themes that embody an innate need to reconcile an ambivalence between cooperating and competing, both with members of the in-group and those of an out-group. Such narratives likely have their origin in our evolutionary past where ethnocentrism and xenophobia led to chronic internecine violence combined with a need for out-group mating and trade. My presentation focuses on statistical thematic data obtained in a sociobiological analysis of 71 oral narratives collected among the Dene Athabascans in the Northwest Territories, Canada in the winter of 1993-94, along with a brief illustrated slide presentation and discussion of one such narrative. Contact information: Department of Ethnic Studies Kin selection and lineage: Cooperative Hunting Groups in Indonesia Anthropologists have long noted that unilineal descent systems are a common way of forming alliances for collective action. Some argue that such systems are incongruous with kin selection theory because one half of one's kin is excluded from those considered culturally as kin. Work conducted among traditional, subsistence whale hunters in Lamalera, Indonesia indicates that hunting groups are more related than expected by chance, but this is because of the correlation between lineage membership and kinship. Crew identifications were collected for all 853 hunts that occurred between May 3 and August 5, 1999. Lineage identity and genetic relatedness were determined for a sample of 220 hunters. Results of matrix regression show that kinship explains little of the hunters' affiliations independent of lineage identity. Below r = 0.5, kin are just as likely not to affiliate because lineage systems disenfranchise half of one's kin. These results support the idea that hunting affiliations are organized according to culturally transmitted, socially constructed identities that serve to mitigate the transaction costs associated with cooperation. Contact information: Texas A&M University Timing of reproductive maturation in South Africa: Testing the Belsky-Draper hypothesis with three ethnic groups Belsky, Draper and colleagues have hypothesized that father absence and childhood psychosocial stress influence the timing of menarche and first sexual intercourse. Numerous studies have supported this model, most of which used data from North American or European samples. In this paper the model will be tested using data on three ethnic groups in South Africa, drawn from Wave I of the Cape Area Panel Study (CAPS). CAPS contains data on sexual behavior and childhood environments for a representative sample of 2,015 young women ages 14-22 living in Cape Town, South Africa. Blacks (n=857), coloureds (n=872), and whites (n=286) are examined separately. Using multivariate Cox proportional hazards modeling to control for censoring, the results support for the hypothesis for whites; both father absence in childhood and childhood household stress predict earlier menarche and earlier first sexual intercourse for whites. Father absence and stress have no effect on either menarche or first sex for blacks. For coloureds, father absence is associated with earlier first sexual intercourse only, and childhood stress has no statistically significant effects. Contact information: Department of Anthropology Kindling and concentration in depression One reason why major depression (MD) is considered maladaptive is because it is thought to increase the likelihood of developing recurrent MD by sensitizing the nervous system to stressful life events (SLEs). A key test is to discern how responsiveness to SLEs changes as a function of depression history. We tested this with an epidemiological sample of twins (4,557 males, 6,038 females) for which we had data on the timing of SLEs and onsets of MD. Survival analyses indicated that a history of MD positively predicted onsets of MD. This was attributable to an increasing risk of developing MD in the absence of reported SLEs. Responsiveness to SLEs also changed, but the results suggest habituation, not sensitization. A history of MD reduced the depressogenic effects of SLEs by 59% in males and 55% in females. This effect was dose-dependent: the more prior episodes of MD, the weaker the depressogenic effects of SLEs. People who get MD may learn something that helps them cope with future stressors. Growing evidence indicates that depression promotes an analytical processing style that may facilitate learning. Implications for understanding the evolution of depression will be discussed. Contact information: Virginia Institute of Psychiatric and Behavioral Genetics Men's reproductive investment decisions: mating, parenting and self-perceived mate value Using questionnaire data completed by 170 men, we examine variation in paternal investment in relation to the trade-off between mating and parenting. We found that as men's self-perceived mate value increases so does their mating effort and in turn, as mating effort increases paternal investment decreases. This study also simultaneously examined the influence of men's mating effort, men's perception of their mates' fidelity and their perceived resemblance to their offspring on investment. All predicted investment. Finally, men with a low self-perceived mate value were less likely to respond to lowered mate fidelity by reducing their parental investment compared to men with a high self-perceived mate value. Contact information: Anthropology Department Testosterone and human aggression: An evaluation of the challenge hypothesis Research on testosterone-behavior relationships in humans is assessed in relation to a version of the challenge hypothesis, originally proposed to account for testosterone-aggression associations in monogamous birds. Predictions were that that testosterone would rise at puberty to moderate levels, which supported reproductive physiology and behavior. Sexual arousal and challenges involving young males would raise testosterone levels further. In turn, this would facilitate direct competitive behavior, including aggression. When males are required to care for offspring, testosterone levels will decrease. Testosterone levels will also be associated with different behavioral profiles among men, associated with life history strategies involving emphasis on either mating or parental effort. Evidence from human studies is reviewed in relation to these predictions, where possible using meta-analysis. Most predictions were supported, although existing studies were not designed to specifically test the challenge hypothesis. Further studies arising specifically from the hypothesis are suggested. Contact information: Department of Psychology Exploring Anxiety and Self-Esteem from an Evolutionary Perspective Gaps in the current understanding of clinical conditions such as anxiety and psychological traits such as self-esteem provide an opportunity to apply evolutionary principles, in an effort to understand and treat behavior that is considered "abnormal". From an evolutionary perspective, certain clinical conditions may be represented as exaggerations of "normal" and adaptive traits that maximized fitness during human evolutionary history. The results of two surveys are presented in order to provide evidence for relationships between fitness maximization strategies and self-report ratings of self-esteem and anxiety. Consistent across studies, anxiety and self-esteem were highly correlated with number of sexual partners and frequency of sexual intercourse. In addition, these studies reveal significant gender differences in anxiety, self-esteem, and sexual behavior. These data add to a growing literature suggesting the use of evolutionary perspective in understanding "abnormal" behavior that may serve to drive clinical and therapeutic treatments. By approaching therapy from an evolutionary perspective, clinicians have the potential to improve the quality of treatment and outcomes for such conditions. Contact information: 3320 Powelton Avenue A new classification and phylogeny of motivations Motivations are brain-based systems that govern the achievement of evolutionarily significant tasks through behaviour. Behaviour monitoring systems determine which motivation should be pursued. Two classes of irruptive systems can lead to change in motivated behaviour: drives and emotions. Drives regulate levels of resources within or impinging on the body, such as nutrients (hunger and thirst), temperature/light (taxis), and gametes (sex). Emotions regulate the organism's relationships with objects that cannot or should not be contacted or consumed: predators (fear), pathogens (disgust), conspecifics (affiliation), social reputation (embarrassment), and norms (shame). Motivational systems have evolved through four phylogenetic stages in the lineage leading to humans, from (1) the Reflexive Stage (Protists), in which proto-motivations were manifest in inflexible responses; (2) the Reward Stage (Chordates), in which responses involved dopamine-based valuation; (3) the Cognitive Stage (Mammals), in which threats to social resources can inspire emotional interrupts: offspring (nurturing-protection), mates (jealousy), reputation (embarrassment); and (4) the Symbolic Stage (humans), in which new emotions govern behaviours supporting social norms (e.g., shame). Contact information: Keppel St Are there content biases in social transmission? The case of animals For some domains of knowledge, one would expect heavy reliance on social transmission of information, because the costs of experience-based learning are high. For example, learning by direct experience that lions are dangerous would be very costly. This suggests that learning which animals are dangerous might rely on a combination of preparation to attend to certain cues (e.g., size, sharp teeth, motion) and reliance on acquisition of information from others. However, what is learned via social transmission might depend not only on what information is available, but in predispositions in the receiver to preferentially attend to some aspects of the information and not others. For example, information about dangerousness might be privileged. I present a series of studies designed to investigate this hypothesis. Contact information: UCLA Department of Anthropology Look who's talking: developmental trends in the size of conversational cliques Work on adult humans has revealed a limit on the size of freely forming conversational groups that has been attributed to the mechanical constraints on human speech production. However, it is also possible that cognitive constraints limit the number of individuals with which it is possible to interact. Data from South African and British children were used to test the hypothesis that the size of children's conversational groups is limited by developmental constraints on children's cognitive skills. Results revealed a significant developmental trend in both clique and group sizes, which mapped onto the developmental trend for metacognitive skills. This cognitive constraint was more pronounced with respect to group size than clique size, suggesting that the inability to monitor more than one conversation prevents children maintaining large groups. A second study on adult conversational cliques revealed that being embedded within a larger group reduced the ability of individuals to sustain conversations over time, providing partial support for our hypothesis. Contact information: School of Biological Sciences The Deceptive Roots of Human Mentation Human mentation arose through and consists of shared self-deception in the service of social cooperation where interests conflict. This process enabled homo sapiens to surmount an evolutionary bottleneck that still traps other intelligent species, and helps to explicate unsolved binding problems in the evolution of language. It arose within social systems governed by indirect reciprocity that were pitted against lethal enemies, with uncertain in-group alliances, and with high risk of in-group punishment. This hypothesis predicts the duality of conscious versus unconscious awareness, and the context-dependence of psychosocial structures. It is confirmed by data from over two centuries of hypnosis research, and their extension into everyday living. Its productivity arises from its ability to integrate many diverse human disciplines. It predicts that cultural units or "memes" are best interpreted as complex interactional phenomena, inseparable from their mode of transmission, highly context dependent, and unlike genes, governed by the rules of motivated intentionality. Contact information: 3006 N.E. Bryce Street Contexts and Circumstances of Filicide-Suicide in Chicago, 1870-1930 The contexts and circumstances surrounding filicide-suicide may provide insight into parental psychology. Previous research on filicide-suicide used a database that includes incident-level information on 22,000 homicides committed in Chicago during 1965-1994. This replicated earlier research indicating that: (1) filicides that include multiple victims are more likely to end in the offender's suicide than are filicides that include a single victim, (2) parents are more likely to commit suicide following a filicide of an older child than of a younger child, (3) older parents, relative to younger parents, are more likely to commit suicide following filicide, and (4) fathers, relative to mothers, are more likely to commit suicide following filicide. The current study uses a database that includes incident-level information on 11,000 homicides committed in Chicago during 1870-1930. We replicate previous work and present findings unique to this time period. Contact information: Department of Psychology An Interactional Model of Parental Investment A child's reproductive value is viewed as the child's ability to convert parental investment into reproductive success. Whereas evidence exists supporting a greater tendency to invest in high reproductive value children (e.g., Daly & Wilson, 1988), this is only half the picture. Decisions concerning parental investment take into account not only the child's reproductive value, but also the parent's access to resources. Under low resources, parents are expected to invest more in their high reproductive value children and less in their low reproductive value children. However under high resources, this pattern of investment is expected to switch with greater investment allocated to their low reproductive value children (because parents can "afford" to do so without neglecting their other children). Evidence supporting the interactional model of parental investment is primarily from the investment patterns of nonhuman parents. However, recently this model of parental investment has been tested and supported among humans as well (e.g., Bugental & Beaulieu, 2003). Further evidence supporting the interactional nature of parental investment among humans will be presented. Contact information: Department of Psychology On the Possibility of Adapted Responses to Dead Agents' Minds We investigated whether (a) people positively reevaluate the characters of recently dead others and (b) supernatural primes concerning an ambient dead agent serve to curb selfish intentions. In Study 1, participants made trait attributions to three strangers depicted in photographs; one week later, they returned to do the same, but were informed that one of the strangers had died over the weekend. Participants rated the decedent target more favorably after learning of his death whereas ratings for the control targets remained unchanged between sessions. This effect was especially pronounced for traits dealing with the decedent's prosocial tendencies (e.g., ethical, kind). In Study 2, a content analysis of obituaries revealed a similar emphasis on decedents' prosocial attributes over other personality dimensions (e.g., achievement-relatedness, social skills). Finally, in Study 3, participants who were told of an alleged ghost in the laboratory were less likely to cheat on a competitive task than those who did not receive this supernatural prime. The findings are interpreted as evidence suggestive of adaptive design. Contact information: Department of Psychology An Evolutionary Theory of Human Motivation: Adaptive Mental Mechanisms and Behavior Motivation is purposeful behavior directed toward the goal of increasing inclusive fitness and motivation may be measured by individual differences in behavior. These individual differences are represented by multidimensional categories of covarying behaviors called "motives". Fifteen putative motives guide surface-level behaviors and interests related to one of five evolutionary social domains that apply to ever larger social systems; solve problems of adaptation by increasing inclusive fitness; and are measurable by strength of interest, desire, or concern with behaviors related to solving problems in a social domain. Motives are mediated by specific neuropsychological structures or mental modules that developed in relation to challenges of environmental problem-solving. As more mental modules developed and the neocortex grew, interactions with ever larger social-cultural environments could be supported. Contact information: Psychology Department Fathers vs Sons: Why Jocasta Matters Back in the 8th century BCE, Heaven hated his children, and hid them away from the light of day. So mother Earth gave one of her sons a sickle, and he 'harvested his father's genitals.' Sons got the better of fathers again in Sophocles' 5th century play - where Oedipus Rex killed his father, and had sex with his mother. In the 20th century CE, Sigmund Freud resurrected the "Oedipus complex," and John Hartung explained it. In a Darwinian world, fathers should fight with sons - not over their wives, but over other women. And 'Jocasta' should determine the winner. Fathers should win when their wives are weak; and sons should win when their mothers are strong. This paper tests that hypothesis on English kings. Weaker queens' sons were less likely to rebel against their fathers, and succeeded at later ages. But a strong queen's son - like Edward III - had his father snuffed out 'with a hoote brooch putte thro the secret place posterialle,' and became king at 14. Contact information: The Adaptationist Program Happy Babies Make Men More Attractive: Evidence for Female Preferences for Parentally-Investing Men The logic of Parental Investment Theory implicates adaptations in women devoted to the assessment of males' willingness to invest in offspring, and adaptations in men designed to detect women's fertility status and seek sexual variety. In keeping with this logic, La Cerra (1994) found that young women perceived a male stranger interacting with a child as more attractive than a male stranger ignoring a child, whereas men rated a female stranger as attractive regardless of context. In two studies, each with a different set of stimulus photos of a male and female pre-rated as slightly-to-moderately attractive, we replicated La Cerra's original research findings. Further, we extended her research by (1) utilizing a between-subjects rather than within-subjects design and (2) investigating potential moderators of sensitivity to cues of parental investment, including sociosexual orientation and egalitarian sex-role attitudes. Contact information: Dept of Psychology Sex Differences: Political, Cultural and Policy Implications As the author of "Sex on the Brain", and as a science journalist specializing in writing about behavioral research, I will discuss the way media attitudes - such as a fascination with the idea that humans are "hard-wired" for behaviors - influences both cultural and individual perceptions of sex differences. Contact information: School of Journalism and Mass Communications Father absence, parent-child relationships and facial attraction in women The purpose of this research was to determine whether or not the father absence literature can be successfully used to predict patterns of female partner preference in adulthood. Study 1 assessed facial masculinity preference, while Study 2 assessed both facial age and real age preference. Predictions were made based on the effect father absence may have on: A. reproductive strategy, B. female 'condition', and C. parental imprinting. Father absence had mixed effects on masculinity preference and was associated with reduced age preference. Daughters who reported low quality relationships with parents showed reduced masculinity and age preferences. These results predominantly support the condition dependence predictions. Contact information: Department of Psychology Kin as Friend and Foe Incorporating evolutionary theory into the study of human behavior requires, amongst many other skills, a sharp appreciation of how specific models are, or are not, appropriate to particular social context. Chagnon's pioneering research with the Yanomamo highlights the importance of appreciating ethnographic context, and more specifically the way in which kinship relations are deployed for individual gain. Building on recent theoretical developments over the factors influencing competition and cooperation among kin I examine how relatives can be either an asset or a liability, depending on the economic circumstances of the family. I test specific hypotheses using both intra and inter-populational variability, drawn from Pimbwe, Datoga, Kipsigis and Sukuma populations in East Africa, looking at child survival and child health outcomes. I conclude, as did Chagnon, that the coefficient of relatedness is only one part of a much more complicated story, and I discuss the implications of this for our field. Contact information: Department of Anthropology Evolution and Fiction As a species, humans invent and imbibe fiction compulsively. Why? I propose a multileveled adaptive explanation, in terms of our adaptations for 1) understanding events (especially our intuitive ontologies, or theories of things, kinds, minds); 2) representing events (narrative); 3) art in general (the evidence suggests that music and the visual arts preceded fiction); and 4) inventing events, in fiction from pretend play to Proust. Fiction cannot be explained as a byproduct even of our capacity for narrative, or in terms of sexual selection. It is an adaptation, its prime function to allow us, with our intensely agential focus, to develop a capacity to think beyond the here and now, and so to free us in some measure from the given. An evolutionary explanation of fiction cannot ignore the role fictions have had in pre-scientific explanation and in religion, but it must still seek to disentangle the functions of "pure" fiction, fiction recognized as fiction. Contact information: Department of English Disentagling Data Representations in Statistical Reasoning In the domain of statistical judgments under uncertainty, there is continuing debate about the "frequency hypothesis"; the idea that frequency representations of information are cognitively privileged based on evolved, ecologically rational, dispositions. Two recent criticisms of this hypothesis have involved the use of "chances," which ostensibly are probabilities rather than frequencies, and the use of pictorial representations to increase the transparency of nested-set relationships (Sloman, Over, Slovak, & Stibel, 2003). Experiments are presented here that are designed to address these criticisms, as well as extend our understanding of human statistical reasoning. It appears that the utility of phrasing data as chances and providing pictorial representations is primarily gained by implicitly inducing frequency representations. Contact information: Department of Psychological Sciences Female WHR, BMI predict male rated physical attractiveness, sexual experience and male behaviour toward target individuals Previous research has often involved the rating of artificial stimuli in relation to waist-to-hip ratio and Body Mass Index. In the present study female participants provided WHR and BMI measurements. Participants then rated their physical attractiveness and a photograph was taken. Results support previous findings with respect to the relations between WHR, BMI and physical attractiveness. Photographs of the female targets were then presented to male raters. WHR predicted male rating of the targets including, physical attractiveness, femininity, promiscuity and sexual experience. Target BMI also predicted ratings of physical attractiveness, masculinity and femininity. The WHR of the target also predicted the males expected behaviour towards the target female including willingness to enter a relationship (both short and long-term), the likelihood that he would remain faithful and that he would become jealous if she spent time with other males. Contact information: Psychology Department, Harrington Building The effect of initial endowment and consistency of preferences in chimpanzees A recent trend examines behavior in nonhuman species, including chimpanzees, in light of existing human economic models, however this may not be warranted. Here, we explicitly test the hypothesis that chimpanzees, like humans, will show consistency of preference for one food over another when endowed with one of the food items. Grapes were consistently the preferred food, and could be exchanged item-for-item with the endowment of carrots (low value), apple (high value), or cucumber (middle value). After extensive training in exchange, each of 10 subjects received 2 carrot sessions, 2 apple sessions, and 8 cucumber sessions. Reactions varied dramatically dependent upon the endowment. All chimpanzees consistently exchange all carrot for grapes and virtually never exchange apple for grapes (1.7% of apples exchanged). When endowed with cucumber, the average number of cucumbers exchanged is remarkably consistent across sessions (range: 12.8%-20.1%), however there is dramatic variation between sessions within an individual, which is not consistent with the human response. We suspect this is due to a variety of factors and discuss implications for the evolution of exchange behavior. Contact information: Department of Anthropology The relationship between fluctuating asymmetry and motion-captured dance movements in rural Jamaica: Is dance a fitness indicator? If the nearly universal association between dance and courtship is due to its utility as a mate quality display, then dancing ability may correlate with other indicators of quality. One such indicator is fluctuating asymmetry (FA). Deviations from perfect symmetry are associated negatively with physical performance, health, survival, and attractiveness in many species, including humans. To test the hypothesis that dancing ability is associated with symmetry, we used motion capture technology to record dance performances of 183 Jamaicans whose FA had been measured previously. Motion capture allows for the evaluation of a dancer's ability independent of his or her outward appearance. As predicted, FA was a negative correlate of dancing ability and perceived energy expenditure assessed from animations. The superiority of motion capture over videotape is shown by the fact that the association between FA and dancing ability is found for evaluations of the motion captures but not in evaluations of videotapes of the same dances. Future studies will include measures of actual energy expenditure while dancing so that we can test whether this perception is accurate. Contact information: Center for Human Evolutionary Studies Women in Science: An Evolutionary Psychological Perspective Harvard President Lawrence Summers's suggestion that innate sex differences might contribute to the dearth of women in science, he provoked many negative reactions. Some asserted that he was simply wrong; some argued that whether or not he was right, he should not have said it; and others argued that although he may be right, we do not have to live with the results. Although evolutionary psychology can shed only indirect light on the latter two arguments, many of its findings bear directly on the first. Evolutionary explanations have been suggested for differences in status-seeking, single-mindedness, attachment to children, preferences for "people versus things," and spatial, mathematical, and verbal abilities. A full explanation of women in science requires accounting for both the fields in which they are "under-represented" and also those in which they are "over-represented." Women earn approximately the same proportion of doctorates in chemistry as men do in psychology, the same proportion in biology as men do in anthropology, and the same proportion in engineering as men do in developmental and child psychology. An explanation that incorporates findings about psychological sex differences accounts much better for observed patterns than one that does not. Contact information: 471 W. Palmer Avenue A Constructive Replication of the Super-K Factor Using the "Mini-K" Short Form We sampled 113 state university undergraduates to replicate the MIDUS K-Factor results. The 20-item Mini-K short-form substituted for the full K-Factor battery, the Rand SF-36 Short Form Health Survey substituted for the Covitality Factor, and the Interpersonal Adjective Scales - Big Five Version (IASR-B5) measured the traditional Big Five Personality factors. Theoretically-specified common factors were constructed. A general Personality factor loaded .76 (p < .0001) on Surgency, .40 (p < .0001) on Nurturance, .66 (p < .0001) on Conscientiousness, -.32 (p < .0005) on Neuroticism, and .59 (p < .0001) on Openness to Experience. The Super-K Factor loaded .70 (p < .0001) on the Mini-K, .66 (p < .0001) on the SF-36, and .72 (p < .0001) on the general Personality factor. The Experiences in Close Relationships questionnaire correlated -.21 (p < .0247) with the Mini-K and -.36 (p < .0001) with the Super-K Factor, again indicating that low-K individuals have problems in close relationships. Contact information: 1303 E. University Blvd. # 20534 The Evolution of Adult Attachment: A Comparative and Phylogenetic Analysis Although the evolutionary functions of attachment in infant-caregiver relationships are undisputed, it is unclear what functions attachment serves in adulthood. The objective of this research was to examine the evolution of adult attachment by applying comparative and phylogenetic methods to archival data for a sample of primates. We found that species exhibiting adult attachment were characterized by paternal care, neoteny, small social groups, and small body sizes. Our additional phylogenetic analyses suggest that the relationship between paternal care and attachment may be due to convergent evolution, but that the relationship between neoteny and attachment may be due to shared ancestry. Contact information: 308 Psychology Building Vocal emotion recognition across disparate cultures Research has demonstrated that basic affective information can be conveyed by the voice independent of the language spoken, but very little research has examined emotion judgments of vocal stimuli across radically different cultures. In the present study, vocal emotion recognition by adults was compared across two disparate cultures: the Shuar of Amazonian Ecuador, and California college students. Shuar and Californian participants reliably identified the intended affect in English sentences produced by native English speakers. Semantically neutral sentences were recorded by speakers while viewing one of five basic emotional faces (angry, happy, sad, fear, and disgust) with the intent to imitate vocally the expression portrayed in the picture being viewed. Participants listened to the sentences of emotional speech and were asked to match individual utterances to the correct emotional face. Shuar performance is compared to California college student performance in the same task, as well as Californian participants in a content-filtered condition. These data suggest that basic affect in the voice contains universal features distinguishable across quite different cultural groups. Contact information: Center for Culture, Brain, and Development The chemistry of seminal fluid and implications for sexual behavior Human seminal fluid contains dozens of hormones, neurotransmitters, immunosuppressants and other compounds that have been shown to both impact human behavior and readily absorb into the bloodstream. In a sample of sexually active college females, condom use, as an indirect measure of the presence of semen in the reproductive tract, was correlated with scores on the Beck Depression Inventory. In particular, somatic symptoms worsened as semen exposure decreased. For females who did not use condoms, the amount of time since their last sexual encounter was also correlated with depression scores. Other variables such as relationship quality, hormonal contraceptive use, and frequency of intercourse had no effect on depressive symptoms. Results are discussed with particular attention to which seminal compounds may be affecting reproductive behaviors, conception and depressive symptoms. Contact information: 404 Mahar Hall Do people find members of their own race more attractive (and if so, why)? Even in modern, multicultural societies, rates of inter-racial dating and marriage are much lower than would be predicted if race-membership was an irrelevant variable in such choices. One possible explanation for this is that people find members of their own race more attractive than members of other races. If so, this could be a consequence of greater familiarity with members of one's own race, or it could be a consequence of past sexual selection operating within races favouring particular facial characteristics. To examine this question Australians of European or North-East Asian ancestry and North-East Asian subjects from Hong-Kong rated the attractiveness of opposite-sex faces of European, North-East Asian or African ancestry, using both individual faces and multi-face composites. Clear preferences for faces of particular races emerged, but the pattern (which was different for male and female subjects) was not entirely consistent with either of the theoretical perspectives. Contact information: Department of Psychology The Murderer Next Door: Why the Mind is Designed to Kill The Murderer Next Door (Penguin, 2005) presents a radical new theory of why people kill. Murder has been a remarkably beneficial strategy that evolved to solve an astonishing array of adaptive problems. These include eliminating poor fitness vehicles, ascending status hierarchies, protecting social reputation, removing cost-inflicting competitors, destroying a rival's reproductive resources, and freeing up resources for future reproduction. Being killed, however, is extremely costly for victims. As soon as murder evolved as a strategy, selection immediately favored anti-homicide defenses, in turn favoring refined homicidal strategies to evade victim's defenses. A perpetual co-evolutionary arms race ensued. A study of 375 murderers and victims provides empirical support for facets of the theory, explaining many otherwise inexplicable design features of murder. The theory also parsimoniously accounts for several paradoxical phenomena, such as why women falsely believe that rapists will murder them despite the low conditional probability of rape-murder, and why people display an inordinate fear getting killed by strangers more than by familiar others, despite the fact that most murderers know their victims, often intimately. Contact information: Department of Psychology The Evolution of Adrenarche in Humans Dehydroepiandrosterone (DHEAS) has attracted much attention as an aging hormone. However, findings that DHEAS supplementation has little effect on mood or memory among the elderly suggests that DHEAS may be unimportant in humans. Such a conclusion ignores the fact that adrenarche (the onset of DHEAS production prior to puberty) is a distinctive feature of human life history, shared only with chimps, and as such requires evolutionary explanation. Here I argue that adrenarche represents an adaptation to help support brain plasticity and continued brain maturation from middle childhood through adolescence and into young adulthood. I present four lines of evidence in support of this theory; 1) increases in DHEAS with adrenarche are the result of histological processes that strongly suggest selection ; 2) DHEAS is a neurosteroid with effects on both synaptic transmission and neural cell growth, suggesting that the brain is the primary target of DHEAS; 3) DHEAS has demonstrable effects on mood and behavior consistent with its neurological effects; 4) the age-pattern of changes in DHEAS parallel those of brain maturation, suggesting that whatever other factors may be involved, DHEAS plays a unique role in brain maturation. Contact information: 232 Bay State Road Individual Differences in the Achievement of Evolutionarily Relevant Goals in Victorian Novels This is a progress report on an ongoing project that replicates and extends earlier Darwinian analyses of characters from canonical British novels (Carroll & Gottschall, 2004). The scope of the project has been extended from 270 characters in 44 novels in the previous study to roughly 2100 characters from 200 novels. Whereas characters in the earlier study were rated by 12 students using novel summaries, thus far over 500 characters in the present study have been rated on the Web by over 900 scholars of 19th Century British literature. Preliminary analyses replicate Carroll and Gottschall's findings of differences between protagonists and antagonists in motives, mate selection preferences, and personal qualities. New findings indicate that successful achievement of five evolutionarily relevant goals (achieving status, building coalitions, being creative, physically surviving, and finding a mate) are significantly related to one or more of the Big 5 personality dimensions for protagonists, but only weakly related for antagonists. The current analyses indicate how Victorian literature embodies assumptions about how individual differences in personality and character impact on life success. Contact information: College Place What massive modularity must be The notion of "modularity" has been given many interpretations in cognitive science, in Fodor (1983) and elsewhere. Which of those notions should be employed, in order that a massively modular account of human cognitive architecture can be defensible? The way to answer this question is to consider the main arguments that have been offered in support of massively modular accounts of the mind, extracting from them a matching account of modularity. These are the arguments from biological design generally, the argument from the organization of learning / animal minds, and the argument from computational tractability. The account of modularity that emerges is much weaker than Fodor's (in particular, modules needn't be encapsulated), but nevertheless substantive enough to be interesting. Viz.: the mind consists of a great many distinct and dissociable processing systems, all of which are computationally frugal in their operations, and with internal processing that is inaccessible elsewhere. Contact information: Department of Philosophy Warre and Striving for Security Among the Yanomamö and Paleolithic Peoples The most widely accepted anthropological theories about prehistoric and primitive warfare are essentially derived from the 19th Century views of Karl von Clausewitz (1780-1831) that warfare was an armed conflict between territorially defined polticial entities (states) with the intent of inflicting lethal harm on the opponents. War was a ‘pursuit of diplomacy by other means’ and it took place in discrete units of time. Curiously, this eurocentric view of warfare stubbornly persists in Anthropology where it is intuitively appealing to accept as the “cause” of some lethal human conflict an explanation that it was a struggle over some scarce material resource. It should not be surprising that materialist explanations of tribal and prehistoric warfare have enjoyed an advantage in an Anthropology, a discipline that is itself is a product of the same concern with material things that gave rise to Capitalism. Contact information: Psychopathology, Sensational Interests, and Mating Effort in a sample of Scottish Adolescents The aim of this study was to ascertain the degree to which sensational interests (SI), mating effort (ME) and psychopathology predict levels of self-reported delinquency in an adolescent sample. 564 adolescents (308:256 M:F mean age 14.1 (SD 0.92)) took part in the study providing measures of personality, SI, ME, psychopathology and self-reported delinquency. Structural equation modelling revealed no link between psychopathology and delinquency, SI or ME. ME showed the highest direct link to delinquency (+0.308) and was linked to delinquency via the militarism factor of SI (+0.206). The path directly from militarism to delinquency was also significant at +0.115. Other measures impacting directly on delinquency included age and low agreeableness. The model from this study is in line with previous findings on ME and offending in adults. It also demonstrates that militaristic SI are partly driven by ME and it is ME which may ultimately be responsible for delinquency and not the interests per se. Militaristic interests may be a manifestation of ME in some individuals. Contact information: Department of Psychology Changes in Romantic Relationships during the Menstrual Cycle: A Diary Study Research has shown that women behave differently during ovulation, when risk of conception is the highest. Additionally, women's preferences of romantic partners also fluctuate during ovulation. Accordingly, it is hypothesized that relationship quality in couples should also fluctuate during the menstrual cycle. Women may become less attentive to their partners, and men may become more jealous of their partners. In this study, 45 couples were recruited to complete a diary study. Couples completed daily diaries for 30 days answering questions about their relationship quality, mate guarding, and other behaviors. Saliva samples were collected from the women to confirm ovulation. Using Hierarchical Linear Modeling (HLM 6.0), changes within the couples during the ovulatory cycle were examined. Contact information: 1433 Beck Spousal homicide in Korea: Analysis of data from the 18th, 19th, and 20th century We performed a comparative and historical analysis of spousal homicide phenomena in Korea over the past three centuries in order to seek the universal operation of evolved psychological mechanism across a range of distinct populations. The data were derived from the 18th and 19th century Korea, a monarchical Confucian society, and from the 20th century Korea, a democratic modern society similar to most European and North American countries. All three datasets were obtained from the official documents of central government organizations, which reflect the actual homicide incidences with high credibility. Despite the samples' evident heterogeneity in their temporal and cultural aspects, they converged on a remarkably consistent pattern of spousal homicide, one that is generally expected from an evolutionary perspective. Males were predominant both as victim and offender in all three datasets. Like modern Western societies, male's sexual jealousy and proprietariness emerged as the most important factor in spousal homicide in old and present Korea. Our results show that the psychological mechanisms involved in homicide may reliably develop and operate over a wide range of contexts. Contact information: Kwanak-ku Shilim-dong San 56-1 Cues of receptivity influence judgements of attractiveness Receptivity cues may influence men's judgements of female attractiveness because they indicate a high probable rate of return for mating effort but women may pay attention to cues of receptivity because they prefer men who display non-threatening behaviour. If this is so, men may be more sensitive to the direction of these cues than women because cues directed at other men do not predict what will be directed toward them. To test these predictions I made use of video stimuli composed of mock interviews with actors. Each actor did one proceptive and one unreceptive interview. Each interview was presented as being directed toward participants or toward an opposite sex interviewer. Proceptivity enhanced the attractiveness of the actors in the eyes of both male and female participants, but an interaction between the state and direction of receptivity was only found when male participants rated female actors. However, the patterns of interaction varied between actors when analyzed separately; it appears to be mediated by physical attractiveness for the female actors but this relationship is less clear for the male actors. Overall, the results support the idea that both men and women monitor cues of receptivity, but in different ways and for different reasons. Contact information: Department of Psychology, McMaster University Attachment and Ecological Condition as Determinants of Female Mate Preferences Whereas attachment theory leads to the prediction that mate preferences (MP) are shaped by parent-child relationships in the family of origin, a behavioral ecological perspective predicts that MP will depend on the availability-predictability of resources encountered in adulthood. To test these contrasting but not necessarily mutually exclusive predictions, 334 female participants from the UK and USA were administered a specially-developed questionnaire assessing MP under three hypothetical ecological conditions that varied the availability-predictability of resources; attachment was assessed with a widely used adult attachment measure. Findings revealed that ecological condition strongly and consistently explained much more variation in female MP than did attachment; at least 50% of the variation in MP, in the USA and UK, was accounted for by ecology. The results demonstrate the need for mate-preference research to pay more attention to ecological conditions. Contact information: Testing the SPFit Model of Addictive Behavior: Development of the Self-Perceived Fitness Questionnaire (SPFQ) Among several evolutionary theories of addictive behavior, Self-Perceived Fitness (SPFit) (Newlin, 2002, Addiction, 97: 427-446) views addiction as the pursuit of stimuli that increase the self-perception of evolutionary fitness (associated with cortico-mesolimbic dopamine system activation) - despite the fact that these stimuli actually decrease fitness. We developed a self-report paper-based measure, the Self-Perceived Fitness Questionnaire (SPFQ), to test hypotheses derived from the SPFit model. We first generated 112 items related to different facets of classical fitness and administered it to 800 undergraduate men and women. We will present principal components and confirmatory factor analyses of these data, as well as evidence of convergent and divergent validity with other self-report measures. This ongoing research represents an initial quantitative exploration of self-reported attributes of evolutionary adaptive fitness. Contact information: 137 Helen Street Tactics of Mate Expulsion Over the course of human evolutionary history it would have been reproductively beneficial to end a long-term mating relationship under a variety of circumstances. Mates could divert resources to others, inflict costs, or merely lose the value inherent in the initial mate selection. Incrementally better mates could become available. Natural selection has likely forged decision rules favoring mate expulsion when the net benefits were sufficient to outweigh the costs. I outline a theory of the evolution of mate expulsion adaptations. The present three studies tested specific hypotheses about the decision rules and mate expulsion tactic usage that follow from this theory. Study 1 identified a diverse set of naturally occurring tactics used to end romantic relationships. In study 2, participants judged the likelihood of performance of a range of tactics. In study 3, participants judged the effectiveness of the same range of tactics. Discussion will focus on tactics men and women judged to be most likely to employ and those judged to be differentially effective. Contact information: Department of Psychology Mirror, Mirror on the Wall: The Long-Term Effects of Experience on Judgments of Attractiveness Although short-term adaptation is known to influence judgments of attractiveness (Rhodes et al., 2003), little is known about long-term effects. Here we took advantage of the documented influence of self-resemblance on attractiveness (DeBruine, 2004) to examine long-term effects of experience by contrasting the normal orientation of a participant's face and its mirror reversal. Participants (n = 48) are asked to choose the face they find more attractive in each of 20 pairs of symmetrised faces that were transformed by 75% of the difference between an average, symmetric face and their own face in its normal orientation versus its mirror-reversed orientation. If there are long-term effects of experience, then participants should select the mirror-reversed morphs as being more attractive because of their experience with their own reflections being greater than their experience with their own photographs. Data from the 20 participants tested to date (all female) indicate that mirror-reversed morphs are chosen as more attractive (t19 = 2.54, p < 0.05, two-tailed), a pattern suggesting that experience can have long-term effects on judgments of attractiveness. Contact information: McMaster University, Department of Psychology Emotion Perception and Expression: Developmental and evolutionary aspects of social behavior in adolescents Is there a link between emotion perception skills and the ability to describe and express prosocial and antisocial behaviors? Is awareness of rejection and belonging linked to a greater ability to recognize facial expressions of emotions? This paper focuses on the developmental aspects of emotional intelligence in 11/12 years old in two schools. 192 pupils were asked to identify facial expressions of emotions (happiness, sadness, fear, surprise, anger, and disgust) from photographs, at the beginning and end of the school year. 18 pupils were asked to identify fear from photographs of facial expressions of emotions, as a part of an in-depth study on fear recognition. The 192 pupils also described an incident in which another child made them happy and an incident when another child upset them. The results demonstrated that there was an increase in mean emotion perception scores. Logistic regression indicated that pupils who described rejection scored significantly higher on the emotion perception task. These results are discussed in terms of evolutionary aspects of emotional intelligence testing, the developmental aspects of fear recognition, and the contribution of an 'awareness of rejection' to group cohesive behavior. Contact information: IDEAS Lab New Darwinism, New Methods: Evolutionary Science and Literary Study This paper will consider the methodological consequences of the concept of human universals as used by Joseph Carroll, Robert Storey, and Brett Cooke, among others, in their proposals for a new Darwinist literary theory. As a scientific hypothesis drawn from the increasingly convergent evolutionary sciences, the concept of human universals has three modes in literary Darwinism: (1) it is a test for the validity of competing theories; (2) it provides for the testing of hypothetical predictions with literary texts; and (3) it suggests the utility of strictly quantitative analyses in literary study. I will briefly evaluate these modes individually, before considering the broader ramifications of the concept of human universals for literary study as a professional practice. Applying scientific understanding to literature calls for clearly spelled-out methodological arguments, and my contention is that literary Darwinism is not entirely coherent when it addresses questions of method. I suggest that as part of the move toward unification of the sciences and the arts from the evolutionary point of view, the methodological arguments of literary Darwinism must become more compelling. Contact information: Department of English Sex Differences in Query Formation It is well known that men and women use language differently. Thus, as web-search tools (e.g. Google) use language-based interfaces, there should be measurable sex differences in tool use. We hypothesise that women will form longer queries, use a larger working vocabulary, and use less frequently occuring words. For tools that are sensitive to these factors, women should be more effective tool users. Using a paper-based survey, we explored the query formation skills of 40 men and women. To evaluate the responses, we are building a language model similar to "word-net" - an English word similarity and frequency model. We have not found significant sex differences for query length likely because search tools are optimized for 3 to 4 word queries and users are aware of this fact. Examination of the data confirm differences in performance on sex-biased tasks (e.g. those related to sports and baking) but without a language model these differences can not be quantified. Contact information: 6050 University Avenue Is patience a virtue? Individual differences in discount rates and cooperativeness In repeated prisoner's dilemmas, the weight attached to immediate versus delayed rewards in part determines whether reciprocity is an evolutionary stable strategy. It is possible then, that in addition to being sensitive to the probability of repeated interaction and to the behaviour of other players, the resulting adaptations for reciprocal altruism are contingent upon the rate at which an individual discounts the future. Specifically, individuals with low discount rates should be more likely to cooperate than people with high discount rates. We tested this prediction by correlating individuals' discount rates with their contributions in a public good game. We found that discount rates were indeed negatively correlated with contributions. One interpretation of this result is that there are mechanisms responsible for discounting future rewards that interact with the mechanisms responsible for reciprocal altruism. Another possible interpretation is that the discount rate test taps directly into the mechanisms responsible for reciprocal altruism. Contact information: 513 North Park Animal disgust: a model emotion In humans it has been suggested that the emotion of disgust serves to motivate behaviour that leads to the avoidance of infection. Since this function is fundamental to any organism, disgust is unlikely to have appeared de novo but to have evolved in our animal ancestors. We demonstrate that this is indeed the case, tracing the phylogeny of the disgust emotion from unicelled organisms, via invertebrates, vertebrates and mammals to humans. We distinguish four functional categories of disgust behaviours (prior to incorporation, during incorporation, after incorporation, and construction of a parasite-free niche). We show how disgust began as a hard-wired reflex, then served as a reward in behavioural learning, and now also serves as a social emotion motivating the shunning of defectors. We conclude that disgust provides an excellent model for understanding the purposes, structure and functions of the emotions in both animals and man. Contact information: Hygiene Centre Human Mate Poaching: How frequent is it and what motivates it? Mate poaching occurs when an individual has sexual relations with the romantic partner of another. In two seminal studies of mate poaching, Schmitt and Buss (2001) and Schmitt (2004) adopted an evolutionary psychological perspective to provide important insights into, among other things, the prevalence of mate poaching and the associated benefits and costs. In the two current studies, we build upon the findings of these studies by using an alternative definition of mate poaching and considering only those benefits and costs exclusively associated with mate poaching. Current findings are discussed and compared with findings of the two aforementioned studies. Contact information: 5701nw 2 avenue #214 Genetic and Environmental Influences on the Frequency of Orgasm in Women This study reports on genetic and environmental influences on the frequency of orgasm in women during sexual intercourse, during other sexual contact with a partner, and during masturbation. Participants were drawn from the Australian Twin Registry. 3080 women responded to the anonymous, self-report questionnaire including 667 monozygotic (MZ) pairs, 377 dizygotic (DZ) same-sex pairs, 366 women from DZ opposite-sex pairs, and 626 women whose co-twins did not participate. Significant twin correlations were found for both MZ and DZ twin pairs for all items of interest. While an independent pathway model fits the data most parsimoniously, a common pathway model incorporating additive genetic, shared environment, and unique environment effects cannot be ruled out. Overall, genetic influences account for approximately 31% of the variance of frequency of orgasm during sexual intercourse, 37% of the variance of frequency of orgasm during sexual contact other than intercourse, and 51% of the variance of frequency of orgasm during masturbation. Contact information: Department of Psychiatry "Teachers or Friends?" Two Hypotheses to Explain our Interest in Celebrity Gossip across the Lifespan. Part of our daily gossip conversation concerns celebrities. The Social Learning Hypothesis explains anyone's interest in celebrity gossip with the fact that we vicariously learn from celebrities' behavior. Opposed to this, the Parasocial Hypothesis explains how some regard celebrities as social network members with whom they have parasocial, or one-way-interactions. Because of this some are interested in celebrity gossip for the same reasons as we are all interested in gossip about real social network members. I tested both hypotheses by interviewing 104 Belgian respondents and distributing a survey among 838 Belgian people. Results show proof for both hypotheses, with strongest support for the Social Learning Hypothesis. Age and sex are the strongest explaining factors for interest in celebrity gossip. Female adolescents are interested the most, and their answers support the Social Learning Hypothesis. As the age of the respondents increases the interest in celebrity gossip declines to almost zero for adults. A revival of interest occurs among elderly people, and their answers are in line with what the Parasocial Hypothesis predicts. Contact information: Korte Meer 7-9-11 Homosexuality: The evolution of a social construction Recent findings are thought to suggest that homosexuality is a trade off for adaptive and fitness enhancing traits. Corna and others (2004), for instance, reported that genetic factors favouring homosexuality in males could increase fecundity in females. Others keep arguing that some forms of homosexuality are adaptations - or at least that they were adaptations in our EEA. The problem with these and other evolutionary explanations of homosexuality is that they take present day homosexuality to be the 'natural phenotype' of homosexuality. I will argue that the history of homosexuality proves this assumption to be incorrect. Indeed, homosexuality is to a large extent 'socially constructed'. However, this does not imply that evolutionary explanations of homosexuality are impossible. Yet, such explanations will have to take into account the importance of cultural niches and their effect on our evolved behavioral patterns and/or modules. Contact information: Facultaire Unie, room E 16.15 Bitching to win The Bachelor. An analysis of the use of gossip in reality television dating shows "Temptation Island" and "The Bachelor" It has been suggested that gossip plays an important role in the context of human mating. Gossip is an ideal tool to combat rivals. By attacking the resource availabilities and willingness to commit of other men, male individuals can lower the mate value of their rivals. Gossiping about the negative physical appearance, promiscuity and chastity of other women, female individuals can rule out their female rivals. Besides this slanderous use of gossip to rule out rivals, gossip is also a handy tool to acquire information about the mate value of potential mates, to learn about the mating structures of our social networks, and to control our own and friends' partners. We analyzed reality television shows "Temptation Island" and "The Bachelor", that both reflect problems of human mating, focusing on the use of gossip by the candidates. Results of our analyses of "Temptation Island" show proof of the use of gossip as a mates-detection advice system and a tool to control mates' cheating behavior. Analyses of "The Bachelor" show proof of the use of slanderous gossip to rule out rivals. Clear sex differences are found in both the content and use of gossip in the context of human mating. Contact information: Korte Meer 7-9-11 Is the sex difference in competitiveness disappearing? A test in populations of U.S. distance runners Sex differences in competitiveness are well established, but it is unknown if they originate from social conditions or evolved predispositions. Testing these hypotheses requires a quantifiable sex difference in competitiveness and the application of a powerful social manipulation to eliminate it. Previous work shows that more male runners seek competition and maintain large training volumes, suggesting that more males should run fast relative to sex-specific world-class standards. In this talk, I provide the first support for this prediction, showing that in matched populations, more than twice as many males as females ran relatively fast in 2003. I then test whether the growth in opportunities for female athletes is eliminating this difference. Although there was an increase in fast female runners in the 1970s and early-1980s, there has been no increase in fast females since the mid-1980s. These results suggest that sex differences in competitiveness reflect evolved predispositions. Contact information: Department of Neurobiology Women's attractiveness judgments of self-resembling faces change across the menstrual cycle Two lines of reasoning predict that women's preferences for people exhibiting cues to kinship will be lower in the follicular phase than in the luteal phase of the menstrual cycle. Women may avoid kinship cues during the follicular phase when they are most fertile due to the costs of inbreeding. Alternatively, women may seek kinship cues during the luteal phase as a byproduct of the benefits of associating with kin during pregnancy, which is also characterized by high progesterone. We find that preferences for facial resemblance, a putative kinship cue, follow this predicted pattern and are positively correlated with estimated progesterone levels based on cycle day. Neither estimates estrogen levels nor conception risk predicted preferences for self-resemblance and the cyclic shift was was stronger for preferences for female faces than male faces. These findings lead to the possibility that this cyclic change in preference for self-resemblance may be a byproduct of a hormonal mechanism for increasing affiliative behavior toward kin during pregnancy, rather than a mechanism for preventing inbreeding during fertile periods. Contact information: "he Perception Lab School of Psychology University of St Andrews St Mary's Quad, South Street What counts as free riding? Using intentions - but not contribution level - to identify free riders For coalitional cooperation to evolve and be maintained, the mind must be equipped with computational procedures designed to identify free riders. But how does the mind define a free rider? Under-contributing can occur by intention or by accident, but only intentional under-contributing reveals a design difference. Four experiments revealed that the mind does not categorize under-contributing per se as free riding. Studies 1 & 2 showed that individuals who intentionally failed to contribute were categorized as free riders, even when holding objective contribution level constant. When intentions were held constant, under-contributing was not used to categorize individuals as free riders - although categorization did occur along a dimension of competence (Study 3). These effects were not due to general categorization abilities (Study 4). The results implicate a procedure specialized for identifying free rider designs as opposed to identifying under-contributing per se. Contact information: Department of Psychology Characterizing Reciprocity in Groups: Information-Seeking in a Public Goods Game Questions remain about the details of the reciprocal strategies people use in the context of group cooperation. We report an experiment in which participants in public goods games could access information about the lowest, median, or highest contribution to the public good before making their own contribution decisions. We found evidence for the hypothesis that adding a cost to view information decreases aggregate contributions, probably because the motivation to induce others' reciprocal contributions diminishes under these conditions. Further, we found that people are willing to endure costs to acquire information, that they have clear preferences for particular pieces of information, and that information preferences vary systematically across individuals according to their contribution strategies. Specifically, participants playing reciprocal strategies sought information about the median contribution and were most willing to pay for information. Free riders, in contrast, preferred to view the highest contribution, while preferences were not consistent across altruists. Contact information: 4507 Spruce St The Shock and Awe of Religion as Memetic Equilibrium In this paper, I examine the origin and development of religious belief in light of varying constraints on human cognitive evolution. Since religions appear to be relatively recent cultural inventions, I examine some of the most influential factors of the EEA of the Upper Paleolithic. I then consider the evidence for the emergence of consciousness and language, the use of human reasoning skills, and specific neurobiological factors, in an effort to develop a hypothesis maintaining that religiosity developed as a memetic response to natural occurrences. As human consciousness evolved, so too did our ancestors' capacity to consider and attempt to solve more environmental problems. Problem solving, when considered satisfactory, produces a feeling of environmental control, stability, in short - memetic equilibrium. But the pay-off is not merely practical, providing purely functional utility (or Survival-Reproductive Value) - it is biochemical - and it comes in the form of endorphins. Contact information: 653 Edinburgh Rd. S. Natural selection and information theory: On the difference between intrinsic and extrinsic inheritance Recently a number of theorists have suggested that evolution can use non-genetic or environmental inheritance in order to pass on adaptations (e.g. Mameli, 2004) and that non-genetic, or environmental factors, can play a central role in the process of evolution (e.g. Odling-Smee, Laland & Feldman, 2003). In this paper I demonstrate that these arguments have muddied the distinction and relationship between intrinsic and extrinsic inheritance. To clarify the true nature of this relationship I apply information theory (Shannon, 1948) to neo-Darwinism. According to this analysis there is no such thing as biologically independent non-genetic inheritance, all extrinsic inheritance is a consequence of traits and dispositions that are intrinsic to an organism and intrinsic design can only be explained through neo-Darwinism. This has implications for current conceptions of cultural evolution. Contact information: School of Psychology Parental Progeny Olfactory Recognition and Kin Investment Although the role of olfaction in kin recognition has been documented in many mammalian species, research on humans has primarily focused on whether parents are able to recognize their children by smell. The present study extends this work by examining what significance olfactory recognition plays in the degree of investment parents make in their children. Specifically we examined whether parents who are able to recognize their children by smell exhibit more affection and attachment, less punishment and more time investment to their children compared to parents who are not able to recognize their children's odor. We compared these associations separately for mothers (N=64) and fathers (N=36) and one or two of their children (4-11 yrs). Consistent with parental investment and sexual selection theories, fathers who were above chance levels in identifying their children showed higher levels of affection and attachment to their children than fathers who were below chance in identifying their children. Mothers' investment was not related to olfactory recognition skills. These results provide the first evidence that olfactory cues may aid fathers in the allocation of parental care. Contact information: P.O. Box 80140 Adaptations for mating relationships involving single parents Due to the death of a spouse or the dissolution of a mateship, single parents were likely a recurrent feature of ancestral environments. I hypothesized four design features of psychological adaptations that may have evolved to address recurrent problems of mating relationships involving single parents. (1) As a strategy to obtain resources or a long-term mate, female single parents will be more agreeable to short-term relationships than women with no children. (2) Their greater agreeableness to short-term mating and demonstrated ability to bear offspring will make female single parents more attractive in some respects as short-term partners than women with no children. (3) Because men typically prefer younger women and women typically prefer older men as mates, men more than women will view single parents' opposite sex children as potential mates. (4) Because the ex-mates with whom single parents had children can inflict costs on new partners, single parents will be more attractive when their ex-mates are absent from their lives. Four empirical studies (Total N = 691) were conducted to evaluate these and other hypotheses. Discussion focuses on the nature of adaptations devoted to mating relationships with individuals who have children from previous relationships. Contact information: The University of Texas After Having Children: Sex-Differentiated Changes in Mate Preferences Empirical evidence for sex differences in mating preferences has been widely documented. Some changes in mate preferences can be attributed to contextual factors. We propose that the presence of a child may be one context in which mate preferences change in a sex-differentiated ways. The current study replicates and extends prior research by examining how the sexes differ in mate preferences after having children. Several hundred participants recruited from a South Florida university completed an online survey asking them to rate a series of characteristics of a potential romantic partner. Results of the current study (a) replicate previous research on sex differences in mate preferences and (b) extend previous research by examining how changes in mate preferences may be attributable to an individual having a child from a previous partner. 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