Anne Kandler - Analysing Language Shift: the Example of Scottish Gaelic
2012-02-13 00:00 (America/Los_Angeles)
Anne Kandler: Santa Fe Institute‘Language shift’ is the process whereby members of a community in which more than one language is spoken abandon their original vernacular language in favour of another. We model the dynamic of language shift as a Lotka-Volterra type competition process in which the numbers of speakers of each language and of the bilingual sub-population vary as a function both of internal recruitment (as the net outcome of birth, death, immigration and emigration), and of gains and losses due to language shift.
In order to test the model we apply our approach to the English-Gaelic competition in Western Scotland. We are able to replicate the main dynamic of the shift process and give predictions about the future of the Gaelic language under unchanged environmental conditions. However, the Gaelic language is subject to recent governmental interventions whose objective are stable societal bilingualism – by creating or preserving segregated sociolinguistic domains, in each of which one or other language is the preferred medium of communication. To consider these effects we examine a second model in which bilingualism is no longer simply a transitional state. Superimposed on the basic shift dynamic there is an additional demand for the endangered language as the preferred medium of communication in some restricted sociolinguistic domains.
The creation of segregated sociolinguistic domains can lead to stable co-existence and therewith be a successful maintenance strategy. Our model enables us to estimate e.g. for the English-Gaelic competition the strength of interventions needed in order to maintain the bilingual sub-population. Further, we analyse the crucial role of random drift for small numbers of speakers of the endangered languages and selective migration on the maintenance success.

Rebecca Sear - How much does family matter? A comparative study of kin influences on fertility
2012-02-21 00:00
Rebecca Sear: London School of EconomicsThe question of why people have the number of children that they do has still not been fully answered, despite decades of research on this topic. Recently, the hypothesis that humans are cooperative breeders has emerged in evolutionary anthropology, which suggests that the support women receive in raising children from other individuals (particularly kin) may be a key part of the answer. Here, I investigate whether the presence of kin influences a woman’s fertility, using evidence from a wide range of populations. I first present the results of a systematic review of all published studies which have investigated correlations between kin availability and female fertility. This review demonstrates substantial evidence that the presence of family members is correlated with fertility, but these results do not always show consistent relationships. In some cases, particularly in high fertility societies and particularly for a woman’s in-laws, kin increase fertility rates. In other analyses, particularly of the influence of a woman’s own parents in low fertility societies, kin slow down fertility. This literature is, however, very varied, with different studies using different methodologies and different measures of fertility and kin availability. More comparative work is needed to elucidate exactly how kin might influence fertility rates. I conclude by outlining my current research programme which aims to investigate kin influences on fertility using existing large-scale demographic datasets, using comparable methodologies in all datasets to facilitate comparisons between populations, and to explore the pathways through which kin may influence fertility.

Steve Cole - Social regulation of gene expression: the primate genome’s social program
2012-02-27 00:00
Steve Cole: UCLA School of MedicineRelationships between genes and social behavior have historically been viewed as a one-way street, with genes in control. Recent analyses have challenged this view by discovering broad alterations in the expression of human and macaque genes as a function of differing socio-environmental conditions. My talk summarizes the developing field of primate social genomics, and its efforts to identify the types of genes subject to social regulation, the biological signaling pathways mediating those effects, and the genetic polymorphisms that moderate socio-environmental influences on human gene expression. This approach provides a concrete molecular perspective on how external social environments interact with our genes to shape the functional characteristics of our bodies, and alter our future biological and behavioral trajectories based on our individual transcriptional histories. http://bec.ucla.edu/posters/Social Regulation of Human Gene Expression – Current Directions 2009.pdfhttp://bec.ucla.edu/posters/Irwin.pdf

Martie Haselton - Can men detect ovulation? (And, if so, why didn't we know sooner?)
2012-03-05 00:00
Martie Haselton: UCLA

Sharlene E. Santana - Adaptive evolution of facial color patterns in mammals
2012-03-12 00:00
Sharlene E. Santana: UCLAThe rich morphological diversity of mammal faces has captured the attention of naturalists for over a century. Researchers have long proposed that social behaviors have primarily shaped the intraspecific variation and interspecific diversity in the faces of some visually-oriented groups such as primates. However, mammal faces constitute complex structures where the potentially competing functions of communication, ecology, and physiology intersect, and the major determinants of facial diversity still remain poorly understood. In this talk, I examine the relationship among facial traits, social and ecological factors within several groups of mammals. Through a phylogenetic comparative approach, I provide the first evidence for an adaptive role of facial color patterns and coloration. For primates in particular, I describe how species living in smaller groups and in high degrees of sympatry with congeners have evolved more complex patterns of facial coloration. Furthermore, the evolution of facial pigmentation and hair length is linked to ecological factors, and ecogeographical rules related to UV radiation and thermoregulation are met by some but not all facial regions. These results demonstrate the interaction between behavioral and ecological factors in shaping facial diversity across mammalian clades.

Mike Gurven - Implications of personality variation in a small-scale society
2012-04-02 00:00
Mike Gurven: UCSBPersonality traits (i.e. behavioral syndrome or disposition) have now been documented in a large number of species, and account for substantial behavioral variation among individuals. How heritable variation in personality is generated and maintained in populations, however, remains a puzzle to evolutionary biologists. Despite the industry of personality research in humans, relatively little tests evolutionary hypotheses and none in small-scale societies experiencing high fertility and mortality. I present personality data from Tsimane forager-horticulturalists and test whether the Big Five dispositional traits are related to fertility, health and other fitness-related outcomes. I also argue that a focus on personality differences can shed insight on small group social dynamics. Results are discussed in light of alternative notions of state-dependence, balancing and fluctuating selection.

Bernard Chapais - Human society: What is it and how did it evolve?
2012-04-09 00:00
Bernard Chapais: University of MontrealThe social structure of any species is an emergent biological phenomenon and as such it has an evolutionary history. The human social structure is no exception to that rule but it has an important peculiarity: it is hidden from view by its numerous cultural expressions. To circumvent the problem and characterize the deep structure of human society one must carry out a comparative analysis of human and nonhuman primate societies and employ evolutionarily significant categories. Using that approach I define human societies as nested associations of multifamily groups, a structure made up of a specific set of features, notably, strong ties between groups stemming from the linkage of kinship bonds and pair bonds, a uniquely human trait. I also argue that primatology makes it possible to define a five-step model of the maximally parsimonious evolutionary sequence that led to human social structure. Finally I show how the present phylogenetic perspective informs functional analyses of human behavior by pointing to the ‘adaptive suite pitfall’and the importance of phylogenetic constraints.

Laura Fortunato - The evolution of the human family
2012-04-16 00:00
Laura Fortunato: SFICompared to other species, humans show a remarkable degree of variation in family organization. This talk presents recent advances in the application of evolutionary thinking to the study of the human family, focusing on the evolution of monogamous marriage. First, I present the results of a game-theoretic model investigating the co-evolution of marriage and wealth inheritance strategies. The analysis shows that where resources are transferred across generations, monogamous marriage may be advantageous because it “concentrates” wealth in a limited number of heirs. It may also be advantageous because a female may grant her husband higher probability of paternity if he marries monogamously, leading to exclusive investment of his resources in her offspring. This may explain why monogamous marriage prevailed across societies of Europe and Asia practicing intensive agriculture, and why it first emerged in these regions: here land was limited and the partitioning of estates depleted their value. Consistently, cultural norms promoting high paternity, such as ideologies of virginity and sexual fidelity, were common in these societies. Second, I present the results of two case studies testing specific predictions of the theoretical model. One case study focuses on evaluating the prediction of an “early” origin of monogamous marriage, linked to the development of intensive modes of production such as plough agriculture. In agreement with this prediction, phylogenetic comparative analysis of marriage strategies across Indo-European-speaking societies reconstructs monogamous marriage as the ancestral state. The other case study focuses on the predicted association between monogamous marriage and norms stipulating the transfer of wealth to a man’s wife’s offspring, as opposed to alternative inheritance strategies. This prediction is supported by analysis of variation in marriage and inheritance strategies across a world-wide sample of societies, while controlling for the confounding effects of Christianization. Finally, I discuss implications of these findings for our understanding of the evolution of human family systems.
*** Please note that due to technical difficulties, the audio quality of the videos has been impaired.

Martin Muller - Behavioral Ecology and Socioendocrinology of Reproduction in Male Chimpanzees
2012-04-23 00:00
Martin Muller: University of New MexicoThe Kanyawara chimpanzees of Kibale National Park have been studied for 25 years, during which researchers have acquired a unique, 14-year longitudinal sample of hormonal data. Dr. Muller will draw on these data to discuss the role that testosterone plays in supporting male mating effort, the energetic costs of male-male competition, and the impacts of such competition on females.

Dawn Neill - Roti or Ramen: The Behavioral Ecology of Food Choice among Rural and Urban Indo-Fijians
2012-04-30 00:00
Dawn Neill: Cal Poly SLOUrbanization is proceeding rapidly in many developing countries as part of a larger process of development and involves the shift of rural residents to urban cities. The shift from a rural to urban ecology entails changes in patterns of food production and/or purchase, preparation, and consumption. Existing research has consistently demonstrated an association between urbanization and dietary changes linked to increasing rates of overweight and obesity. Rural-urban variation in food cost and availability modifies the individual-level costs and benefits associated with dietary choices. It is suggested that the traditional rural dietary pattern is undergoing modification as urbanization occurs and individual food choice tradeoffs result. Empirically-derived diet clusters are created from 24-hour dietary recalls from 306 urban and rural living Indo-Fijian children. Results suggest the existence of a rural-traditional vegetable-based pattern and an urban-modified pattern. Using an embodied capital framework, mother’s education is shown to be the strongest predictor of diet, along with number of offspring and parents’ childhood ecology; urban ecology does not significantly predict diet. Mother’s embodied capital is also shown to be significantly associated with higher child BMIs, regardless of diet.

Colin Holbrook - Why Thoughts of Death or Isolation Magnify Group Prejudice
2012-05-07 00:00
Colin Holbrook: UCLAHumans are inclined to cherish their communities and derogate groups regarded as alien, particularly during times of threat. The capacity for threatening circumstances to exacerbate group prejudice holds both social relevance and theoretical interest, and has been widely discussed within psychology and evolutionary anthropology. Perhaps the most intensively studied experimental measure of group bias following threat has been worldview defense. Worldview defense is a psychological effect wherein subtle reminders of death, coalitional challenges (e.g., isolation) or other poignant threats magnify preferences for affirmations and against criticisms of cultural in-groups. Proponents of terror management theory and coalitional psychology postulate alternative interpretations of worldview defense as the output of adaptations evolved to (i) allay the fear of death or (ii) foster social support during times of trial. In contrast to both of these proposals, I will present evidence that worldview defense tokens a relatively domain-general capacity for unconscious vigilance. Unconscious vigilance is hypothesized as a state of accentuated reactivity to emotional targets (which need not relate to cultural worldviews) evoked upon detection of subtle alarm cues (which need not pertain to death or coalitional challenges). Consonant with the unconscious vigilance account of worldview defense, cross-cultural research conducted in Tibet, Northern Ireland, and the United States confirms that both death and isolation cues exaggerate ratings of affective targets unrelated to group attitudes, and, conversely, that threat manipulations unrelated to death or isolation evoke worldview defense. In addition to evidence for an unconscious vigilance pathway to worldview defense, I will introduce new results demonstrating that conscious feelings of positive affect induced by reward cues can also heighten group prejudice. These overall results will be discussed as they inform evolutionary interpretations of worldview defense.

Sergey Gavrilets - On the evolutionary origins of the egalitarian syndrome
2012-05-14 00:00
Sergey Gavrilets: University of TennesseeHumans exhibit strong egalitarian syndrome, i.e. the complex of cognitive perspectives, ethical principles, social norms, and individual and collective attitudes promoting equality. The universality of egalitarianism in hunter-gatherers suggests that it is an ancient, evolved human pattern. The evolutionary emergence of this syndrome is one of the most intriguing unsolved puzzles related to the origins of modern humans. Using simple mathematical models I will explore possible routes for two important aspects of egalitarian behavior: the transition from promiscuity to pair-bonding and coalitionary control of bullies.

Robert Frank - Rivalry and Cooperation: A Darwinian Perspective
2012-05-17 00:00
Robert Frank: CornellNote: this talk will begin at 3:30pm.
Economists since Adam Smith have insisted that competition produces the greatest good for the greatest number. But as Charles Darwin emphasized, individual and group interests do not always coincide. And when they clash, individual interests tend to trump, often resulting in wasteful arms races. The Darwinian perspective suggests that many forms of market failure that in the past have been attributed to monopoly or limited rationality are instead more plausibly the result of individual-group conflict. The Darwinian perspective also suggests, however, that many other presumed forms of market failure–such as the breakdown of cooperation when cheating cannot be detected- may be less serious than most economists believe.

Clark Barrett - Confronting the puzzle of evolutionary novelty
2012-05-21 00:00
Clark Barrett: UCLAThe capacity of organisms to deal with evolutionary novelty has been regarded by some as a puzzle. If adaptations have been shaped by natural selection operating in the past, then how can they possibly respond adaptively to objects, events, and situations that clearly did not exist until recently? This has been regarded as particularly problematic for adaptationist accounts of human behavior because we are clearly surrounded by many evolutionary novelties, from football to Facebook, that do not cause our brains to seize up in a failure to compute. Traditionally, the answer has been that humans are equipped with more or better general-purpose cognitive capacities than are other animals, though mounting comparative evidence suggests that it is not primarily in the most general mechanisms of cognition that humans and other primates differ. Arguably, progress on the novelty puzzle has been impeded by the lack of adequate theory regarding how adaptations, and in particular psychological adaptations, might be expected to respond to evolutionary novelty. In this talk I describe elements of what such a theory might look like, drawing on prior work in biology, evolutionary psychology, culture-gene coevolution theory, and Bayesian models of cognition, and illustrating the ideas with examples from recent research.

Adrian Jaeggi - Food sharing in human and non-human primates
2012-05-28 00:00
Adrian Jaeggi: UCSBFood sharing is a vibrant field of study that has provided important insights into the evolution of cooperation, life history, and social learning. Common functional explanations for sharing include nutritional and informational benefits to offspring, tolerated scrounging, kin selection, reciprocal altruism, and costly signaling. I review the most important findings regarding food sharing in primatology and human behavioral ecology and sketch out the phylogenetic history of these functions. I draw attention to aspects of primate and human food sharing that are sometimes underappreciated but carry important implications for understanding evolved life history and the psychology of pro-sociality: Shared foods comprise a negligible part of the diet in most primates, contrasting with the obligatory provisioning of multiple dependent offspring by several caretakers in callitrichids and humans. Slow growth, delayed juvenility and heavy provisioning lead to extended periods of net consumption in human families and a resulting dependence on between-family sharing. Food transfers both within and between families are therefore an integral part of human life history which has likely been facilitated by the extended kin networks of humans compared to that of a chimpanzee-like ancestor. The negotiation of sharing norms in relation to different production regimes, and the strategic use of sharing as a costly signal are key components of human exchange relations. On the other hand, sharing among adult primates is best understood as an occasional manifestation of long-term social relationships within which services like grooming, selective mating, and coalitionary support are exchanged more routinely. These functional differences may explain why sharing among primates is predominantly passive, whereas humans seem to have evolved a more active sharing psychology.http://www.bec.ucla.edu/papers/jaeggi-food-sharing.pptx

Jeff Snyder - He Would Never Hurt Me: Women’s Preferences for “Tough Guys”
2012-06-04 00:00
Jeff Snyder: UCLAIn general, women in the U.S. appear to prefer prestigious men to dominant men under most circumstances. However, some women select domineering men as long-term intimate partners – sometimes at a high cost to themselves. Such women are likely sensitive to their self-perceived vulnerability to danger, and hence may select domineering men when the benefits of the protection that such men can provide outweigh the costs that they may inflict on their partners. Evidence suggests that women prefer formidable, domineering, and aggressive men when they also report relatively higher fear of crime. This effect appears to be independent of socio-economic status and does not appear to be better explained by a promiscuous socio-sexual orientation or life history variables such as father absence. In addition, preliminary evidence suggests that while women recognize at a general level that pair-bonding with aggressive and formidable men can be costly, women in such relationships do not report that their partners are domineering or coercive with them. This latter phenomenon may be the result of self-deception, allowing women to discount the costs of pair-bonding with such men.

Hanah Chapman - Moral Disgust Discussed: Emotional and Cognitive Contributions to Human Morality
2012-10-01 00:00
Hanah Chapman: Ohio State UniversityBeing lied to, cheated upon, stolen from—these are among life’s most emotional experiences, and even watching them happen to someone else can trigger strong feelings. Recent work has confirmed the important role of emotion in human morality, but less is known about precisely which emotions are involved and how emotion exerts its influence. In this talk, I discuss the role of distinct emotions in morality, with a focus on disgust. I also describe a new line of research that aims to examine how emotion and cognition interact to give moral values their special weight in decision-making. Taken together, these two lines of work suggest that both emotion and cognition are key contributors to human morality.

Hillard Kaplan - Tsimane Aging and Human Life History Evolution
2012-10-08 00:00
Hillard Kaplan: The University of New MexicoThis talk examines what we have learned about the aging process among Tsimane forager- horticulturalists, and the implications of our results for understanding human life history evolution. I review our latest findings on behavior, inter-generational transfers, physical function, immunocompetence and cardiovascular disease. Tsimane men and women remain net producers until about age 70, the modal age at death for traditional populations, with significant downward transfers to descendants. They also show that men and women adjust their time use as they age, adapting to physical decline. Cardiovascular disease is rare, and heart function remains preserved into the eight decade of life. Immunosenescence, along with functional declines, appears to be the major driver in the increasing risk of mortality with age. The lecture concludes with a discussion of the theory of human lifespan evolution, and important new directions for research.

Noa M. Pinter-Wollman - Individual variation in Collective Behavior
2012-10-15 00:00
Noa M. Pinter-Wollman: The University of California, San DiegoThe behavior of biological systems emerges from the
self-organization of multiple agents that interact with one another
and follow simple local rules. However, not all individuals within the
system are identical. I study how individual variation in the behavior
of worker ants affects the behavior of the colony, a complex
biological system, as a whole. In social insects, natural selection
acts at the colony level. Colonies of harvester ants use interactions
among workers to closely regulate their foraging activity and balance
the trade-off between acquiring food and loosing water due to
desiccation while foraging. I will present empirical work from the
field and lab along with computer simulations to show how individual
variation in worker behavior affects the speed of information
processing by colonies. I further show that colonies vary in how they
adjust their collective behavior to environmental cues linking
variation at the colony level to behavioral variation among individual
workers. By exploring the causes and consequences of individual
variation within and among social insect colonies I hope to further
our understanding of how complex biological systems operate and
evolve.

Steven J. Heine - Positive Self-Views, East and West
2012-10-22 00:00
Steven J. Heine: University of British ColumbiaA core psychological motivation for people is to view themselves positively, yet for decades the vast majority of evidence for this motivation came from North American samples. More recent research finds that this motivation varies importantly across cultures, because there are different kinds of positive views that are prioritized in different cultures. Positive self-views are primarily made manifest in North America through a desire to maintain high self-esteem – that is, a desire to have a positive evaluation of themselves. In contrast, the kind of positive self-view that is prioritized in several East Asian cultures is a strong desire to maintain face – that is, a desire to have others in one’s social network judge that the individual is functioning adequately in their position within that network.
These two distinct kinds of positive self-views are associated with highly divergent psychological processes. In their efforts to maintain high self-esteem, North Americans demonstrate stronger tendencies for self-enhancement, they show more of a promotion focus, maintain a largely internal frame of awareness, and have more entity theories of abilities. In contrast, in their efforts to maintain face, East Asians show stronger tendencies for self-improvement, demonstrate more of a prevention focus, maintain a largely external frame of awareness, and have more incremental theories of abilities. Evidence for cultural variation in each of these processes will be discussed, alongside discussions of alternative explanations.

Frances Chen - The Neurobiology of Sensitivity to Social Support and Interpersonal Conflict
2012-10-24 00:00
Frances Chen: University of FreiburgSocial relationships are a source of support and comfort in our lives, as well as a source of stress and conflict. Thus, the ability to regulate responses to both positive and negative emotions and cognitions arising from social interactions can significantly influence both physical and mental health. In my talk, I will present evidence from two studies suggesting an early-emerging and persistent role of the oxytocin system in sensitivity to social support. Specifically, common variants of the oxytocin receptor gene (OXTR) predict physiological, psychological, and behavioral responses to social support and stress in both adults and infants. I will also present results from a third study exploring the role of the oxytocin system in human social approach behavior. In addition, I will discuss my ongoing research on how internal working models of relationships (e.g. perceptions and beliefs about the status and intentions of social partners) interact with neuroendocrine activity to influence responses to social stress and interpersonal conflict.

Rafael Nunez - Making sense of Time: Body, Ecology, and Culture in Human Abstraction
2012-10-29 00:00
Rafael Nunez: The University of California, San DiegoTime, a fundamental aspect of human experience, is elusive and abstract. We cannot perceive time directly through the senses in the way we perceive color, texture, or heat. In order to make sense of, and talk about, temporal experience we must construe it in a stable and tractable manner. This is achieved via cultural practices built on the recruitment of bodily-grounded mechanisms that make human imagination possible, such as conceptual mappings. This remarkable but ubiquitous phenomenon manifests itself via ordinary linguistic metaphors as in the English expressions “the week ahead looks great” and “way back, in my childhood.” Furthermore, beyond words and grammar, this phenomenon can be observed also through largely unconscious motor actions co-produced with speech — spontaneous gestures, which reveal its deep conceptual nature. But, is the human conceptualization of time universal? Based on shared general features of body morphology there is a widespread egocentric pattern which places future in front of Ego and past behind, as in the above linguistic examples. However, there are striking variations as well, which can be documented with rigorous ethnographic linguistic/behavioral observations. In this presentation I will show data from our projects conducted among the Aymara of the Andes, and the Yupno of the mountains of Papua New Guinea. The Aymara operate with a “reversed” egocentric pattern in which the future is conceived as being behind Ego and the past as being in front. More recently, and perhaps even more strikingly, we found that the Yupno spontaneously construe time spatially not even in egocentric terms, but in terms of allocentric topography: past as downhill and future as uphill — a pattern that had not been documented before. Moreover, the Yupno construal is not linear, but exhibits a particular “bent” geometry that appears to reflect the local terrain. Our results show that humans make sense of time sharing some basic spatial universals, but that striking differences also exist regarding the types of spatial properties that are recruited for spatializing time. The findings shed light on how, our universal human embodiment notwithstanding, linguistic, cultural, and environmental pressures generate and come to shape abstract concepts.

Christina Palmer - Maternal-Fetal Genotype Incompatibility as a Risk Factor for Schizophrenia
2012-11-19 00:00
Christina Palmer: The University of California, Los AngelesPrenatal/obstetric complications are implicated in schizophrenia susceptibility. Some complications may arise from maternal-fetal genotype incompatibility, a term used to describe maternal-fetal genotype combinations that produce an adverse prenatal environment. As will be described, maternal-fetal genotype incompatibility can occur when maternal and fetal genotypes differ from one another, or when maternal and fetal genotypes are too similar to each other. Incompatibility genes for each of these scenarios have been implicated as risk factors for schizophrenia and a review of maternal-fetal genotype incompatibility studies suggests that schizophrenia susceptibility is increased by maternal-fetal genotype combinations at the RHD, ABO, and HLA-B loci. Maternal-fetal genotype combinations at these loci are hypothesized to have an effect on the maternal immune system during pregnancy, which can affect fetal neurodevelopment and increase schizophrenia susceptibility. During this presentation, data will be synthesized and the hypothesized biological role of these incompatibility genes in the etiology of schizophrenia will be described.

Georg Striedter - What's Special About Human Brains?
2012-11-26 00:00
Georg Striedter: The University of California, Irvine. Human brains are much larger than one would expect for primates of our body size. They also feature more neurons and a proportionately larger neocortex. Prefrontal cortex, in particular, is significantly larger in humans than in other species. Although these features make the human brain unique, most of them are in line with allometric expectations, meaning that they can be predicted from the large size of our brains. Thus, human brains are fairly typical primate brains; they just became unusually large. Nonetheless, there are good reasons to believe that the evolutionary expansion of the human brain, especially of prefrontal cortex, caused evolutionary changes in neural connectivity and function. Dr. Striedter will review some of the evidence supporting this idea and place it in the larger context of brain and behavioral evolution.

Scott A. Reid - Perceived Distance Between Accents, Religious Groups, and Attraction to Ingroup-Accented Speakers, is Calibrated to the Costs of Infection Risk
2012-12-03 00:00
Scott A. Reid: University of California, Santa BarbaraThere is evidence that humans have adaptations to avoid outgroup members who potentially harbor novel pathogens. However, intergroup contact can produce fitness costs (e.g., violence and disease), or benefits (e.g., trade, mates, and technologies), which suggests that it would be beneficial to possess an adaptation that enables the accurate tracking of group memberships. We predicted that accurate group tracking is accomplished through cognitively differentiating between social groups, and that this differentiation would be calibrated to the potential risk of infection. Consistent with this hypothesis, we found that increases in pathogen disgust are associated with increases in perceived similarity to ingroup-accented speakers and perceived dissimilarity from outgroup-accented speakers, particularly after exposure to pathogenic stimuli. Further, the effect of pathogen disgust on the accuracy of social categorization was mediated by intergroup differentiation. In this talk I present evidence for this group tracking hypothesis for accents, as well as recent evidence that extends the hypothesis to perceptions of similarity to religious groups, and to female judgments of the sexual attractiveness of ingroup- over outgroup-accented male speakers.

Aaron Lukaszewski - The Origins of Heritable Personality Variation: An Integrative Evolutionary Approach
2013-01-07 00:00
Aaron Lukaszewski: Loyola Marymount UniversityTwo basic questions in the study of personality origins are (1) Why do people vary in their personality trait levels? and (2) Why do distinct trait dimensions covary in consistent patterns within individuals, rather than varying independently? The current presentation describes an integrative evolutionary framework within which both of these questions can be addressed, and highlights supportive empirical findings. For instance, since physical strength and physical attractiveness likely predicted the reproductive payoffs of extraverted behavioral strategies across most of human history, it was theorized that extraversion levels are facultatively calibrated to variations in these phenotypic features. Confirming these predicted patterns, strength and attractiveness together explained a surprisingly large fraction of the variance in extraversion in Studies 1 and 2 – effects that were independent of variance explained by an androgen receptor gene polymorphism. Study 3 then provided evidence that the covariation among a wide array of interpersonal traits (e.g., extraversion, emotionality, attachment styles) is orchestrated by their facultative calibration in response to common input cues. Overall, these findings suggest that multiple types of proximate mechanisms – facultative calibration and specific gene polymorphisms – operate in concert to determine adaptively-patterned personality (co)variation. http://bec.ucla.edu/papers/Lukaszewski_BEC.pdf

James W. Pennebaker - Using function words to understand people, groups, and culture
2013-01-14 00:00
James W. Pennebaker: University of Texas at AustinThe smallest and most frequently used words in English are function words — pronouns, prepositions, articles, auxiliary verbs, etc. These overlooked words are profoundly social and can signal the ways people think, feel, and relate to others. Using a variety of text analysis methods, it is possible to track function words to deduce an author’s age, sex, social class, personality, honesty, status, and emotional state. By analyzing ongoing interactions, the degree to which couples, groups, or larger entities are listening to and effectively communicating with others can be estimated. The function word analytic approach has interesting implications for research projects in the social sciences, humanities, education, business, medicine.

Mark Handcock - Statistical Modeling of Social Networks
2013-01-28 00:00
Mark Handcock: University of California, Los AngelesIn this talk we give an overview of social network analysis from the perspective of a statistician. The networks field is, and has been, broadly multidisciplinary with significant contributions from the social, natural and mathematical sciences. This has lead to a plethora of terminology, and network conceptualizations commensurate with the varied objectives of network analysis. As the primary focus of the social sciences has been the representation of social relations with the objective of understanding social structure, social scientists have been central to this development. We illustrate these ideas with Exponential-family random graph models (ERGM) which attempt to represent the complex dependencies in networks in a parsimonious, tractable and interpretable way. A major barrier to the application of such models has been lack of understanding of model behavior and a sound statistical theory to evaluate model fit. This problem has at least three aspects: the specification of realistic models; the algorithmic difficulties of the inferential methods; and the assessment of the degree to which the network structure produced by the models matches that of the data.
We will also consider latent cluster random effects models and touch upon issues of the sampling of networks and partially-observed networks.
We illustrate these methods using the “statnet” open-source software suite (http://statnet.org).

Ben Karney - Gender Differences in the Importance of Attractiveness and Weight in Established Romantic Relationships
2013-02-04 00:00
Ben Karney: University of California, Los AngelesAmong strangers, no variable has as much power to predict interpersonal judgments as physical appearance. In particular, more physically attractive people are judged as more desirable romantic partners, and generally males have been found to be more affected by a partner’s physical appearance than females. But does physical appearance continue to play a role in established relationships? We addressed this question across several studies of the early years of marriage. Drawing upon observational data on newlywed’s marital interactions, and longitudinal data on the trajectory of their marital satisfaction over time, these studies examined how the facial attractiveness of each partner (as rated by objective observers) and the body mass index (BMI) of each partner accounted for relationship processes and outcomes. In general, these results suggest that, in established relationships, the absolute level of each partner’s attractiveness matters less than the relative attractiveness of partners within the couple. Moreover, we observe consistent gender differences, such that outcomes are more favorable in couples wherein wives are more attractive than their husbands, and less favorable in couples wherein husbands are more attractive than their wives.

John Capitanio - Personality in rhesus monkeys: Some proximate, ultimate, and practical considerations.
2013-02-11 00:00
John Capitanio: University of California, DavisThere has been a growing interest in the study of animal personality, and nonhuman primate research has played a significant role in this field for many decades. My research program has focused on the causes and consequences of variation in personality dimensions in rhesus monkeys (Macaca mulatta). In this talk, I will focus on recent and current studies of prenatal and early postnatal influences on personality, some physiological mechanisms by which personality is associated with health outcomes, and implications of variation in personality for fitness-related outcomes, as well as for outcomes associated with management of captive primate colonies.
