Jeff Snyder - He Would Never Hurt Me: Women’s Preferences for “Tough Guys”
2012-06-04 00:00 (America/Los_Angeles)
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.

Lynn Fairbanks - Developmental Programming and Resilience in Vervet Monkeys
2013-02-25 00:00
Lynn Fairbanks: UCLAThere has been considerable interest in gestational and neonatal influences on developmental trajectories in humans and other mammals in recent years. This presentation reviews results from the Vervet Research Colony demonstrating effects of maternal condition, diet and weight loss on maternal and infant behavior. To understand the impact of variation in maternal investment on development, it is important to recognize that infants are not simply the passive recipients of variation in maternal care. Mothers and infants adjust their behavior in relationship to one another, with the mother responding to her own condition, and the infant trying to counteract attempts to limit maternal care.
Longitudinal effects of maternal condition on juvenile behavior are then examined from contrasting theoretical perspectives, including developmental canalization, fetal programming, resilience, and stress inoculation theories. Results suggest that behavioral development is largely resilient to developmental challenges within an expectable range of experience. They provide support for stress inoculation theory in that juveniles who experienced higher levels of early maternal rejection as infants became more active promoters of their own social development, while the inhibitory effects of adverse early experience on juvenile behavior were more evident under novel and challenging circumstances. The results are consistent with the view that infant and juvenile behavior evolved in the context of variation in maternal care, and selection has favored strategies for immature offspring to get what they need for physical and social development.

Barry Hewlett - Teaching, Trust, and Social Learning in Aka Forager Infancy
2013-03-04 00:00
Barry Hewlett: Washington State University, VancouverCultural anthropologists Margaret Mead, David Lancy, and Barbara Rogoff indicate that teaching does not exist or is rare in small-scale cultures. By contrast, recent research by cognitive neuroscientists Gyorgy Gergely and Gergely Csibra indicate that one type of teaching, called natural pedagogy, is a human universal, part of human nature, and not found in the great apes. They hypothesize that this form of teaching emerges in infancy and that it enhances humans’ ability to faithfully transmit “opaque” cultural knowledge, such the function of a particular tool. Learners evolved to pay attention to particular cues, such as eye and body movements, and teachers evolved the skills to convey important information to learners, such as pointing, using personal names, looking at or making sounds about important knowledge. Cognitive science research on natural pedagogy is limited because all of their studies have been conducted in laboratories with Western infants. This study uses videotapes of 10 Aka hunter-gatherer 12-14 month-old infants in naturalistic settings to evaluate the natural pedagogy hypothesis. The study shows that natural pedagogy exists in hunter-gatherers, but that it occurs relatively infrequently. The study also identifies two other forms of hunter-gatherer teaching—distributed teaching and opportunity scaffolding–that are rare or do not exist in the great apes and occur more frequently than natural pedagogy. The talk suggests that interactions between inherent evolved cognitive mechanisms, such as natural pedagogy, and culturally constructed niches of hunter-gatherers that promoted trust, enhanced social learning and made cumulative culture a distinctive feature of modern Homo sapiens.

Montserrat Soler - Rituals, Adaptions and Exaptations: Integrating Conflicting Perspectives on the Evolution of Religion
2013-03-06 00:00
Montserrat Soler: University of California, Santa BarbaraIn the last ten years, there has been a surge of work dedicated to the study of religion from the point of view of evolutionary studies and cognitive science. These accounts of religion are divided into two main areas: one views religious concepts as by-products of other cognitive capacities, while the other argues that belief and ritual are adaptations that promote intra-group cooperation. A novel way to integrate these approaches is to think of religion as a dynamic system where signalers (religious authorities) and receivers (religious followers) are engaged in a continual interaction of exploitative and cooperative strategies. Here, I will present this idea in three sections. First, I will describe how investigating the costs and benefits of religious authority and the receiver psychology of religious followers can help us understand why people believe and how those beliefs are transformed into directives for both cooperative and maladaptive behavior. Second, I will present results from an agent-based simulation model that explores the success and failure of individual signaling strategies in different conditions. In the model, different religious systems may function as risk-pooling enterprises in variable environments where leaders and followers alternate honest and dishonest signaling to compete for available resources. Finally, data from an African diasporic religion will be presented to explore the relationship between religious leadership, status and intra-group cooperation and to indicate directions for future research.

Michelle Kline - Human adaptations for teaching: A new theoretical framework and empirical tests from Fiji
2013-04-01 00:00
Michelle Kline: The University of California, Los AngelesHumans are heavily reliant on cultural adaptation, and have coevolved
with culture for millennia. Teaching enhances the fidelity of cultural
transmission and should be common in such a culture-dependent species.
However, existing data present a puzzle concerning the role of
teaching in human evolution. While biologists have documented
teaching in a number of non-human animal species, extant ethnographic
work suggests that teaching is rare in non-Western human societies.
Both sets of findings are hotly debated. I argue that disputes about
the nature and prevalence of teaching across human societies can be
resolved within an evolutionary framework that distinguishes among a
range of teaching behaviors with varying costs and benefits to
teachers and learners. This framework predicts that some teaching
behaviors should be common across societies, within particular
relationships, and for the learning of particular kinds of skills.
Here I present this new theoretical framework and confirm a number of
its predictions using two data sets from fieldwork with
fishing-horticultural villages on Yasawa Island, Fiji.

Lucia Jacobs - Chemosensory cognition and the evolution of olfaction
2013-04-08 00:00
Lucia Jacobs: University of Caliornia, BerkeleyThe chemical senses of vertebrates present some of the most enduring mysteries of brain evolution. First, it is not clear why are there two olfactory systems: the main system (MOS), detecting odorants on the olfactory epithelium and projecting to the olfactory bulb, and the accessory system (AOS), detecting odorants in the vomeronasal organ and projecting to the accessory olfactory bulb. More perplexing, taxonomic patterns of olfactory system presence and size cannot be explained by any current hypothesis, whether behavioral or phylogenetic. Yet the two systems vary immensely in structure and complexity across vertebrates, particularly in primates. Rather than assuming that the size of an olfactory system scales with the need to discriminate a class of odorants, I propose a new hypothesis: that the MOS evolved as a navigation system, to map the aqueous chemical world experienced by the early vertebrates. I further propose that this function retained its primacy in land vertebrates, and that this spatio-temporal hypothesis of olfaction offers a new explanation for the patterns of neural architecture, plasticity and allometry of olfactory systems in vertebrates.

Rich Connor - Multi-level dolphin alliances in Shark Bay
2013-04-15 00:00
Rich Connor: University of Massachusetts DartmouthFor over 25 years we have documented a multi-level alliance structure among male bottlenose dolphins in Shark Bay, Western Australia. Males cooperate in pairs and trios, ‘1st-order alliances,’ to form temporary consortships with individual females. First-order alliance partners are drawn from a male’s second-order alliance. Second-order alliances have 4-14 males and may be stable for over two decades, but occasionally lose or take in new members. First-order alliances vary in stability but this variation is not strongly related to 2nd order alliance size. Members of 2nd order alliances engage with conflicts with other groups over females, sometimes in the company of other 2nd order alliances they associate with, suggesting a 3rd alliance level. The male alliances and individual females live in an open social network where both sexes maintain their mother’s natal range as part of their adult home range. The study area can be divided into a subdivided area characterized by shallow offshore flats bisected by deeper channels and an open habitat. Trios predominate in the open habitat while pairs are common in the subdivided habitat. Further, the largest 2nd order alliances (>9) use the open habitat at least part of the year. The combination of 120 males with known alliance affiliations combined with recent technological advances presents an exciting future for studies on the development, communication, genetics and ecology of alliance formation.

Nancy Segal - Twins Raised Apart and other Unusual Pairings: Genetics, Personality and Social Relatedness
2013-04-22 00:00
Nancy Segal: California State University, FullertonAn overview of the origins, methods, findings, implications and controversies from the Minnesota Study of Twins Reared Apart is provided. This study, which took place between 1979 and 1999 at the University of Minnesota, accumulated a wealth of behavioral, physical and medical data on 137 reared apart twin pairs, 81 monozygotic (MZA) and 56 dizygotic (DZA). The focus will be on the personality and twin relationship findings, and their comparison with comparable data from an ongoing study of personality similarity and social relatedness between unrelated individuals who look alike, but are genetically unrelated (U-LAs). The U-LAs allow unique assessment of issues and questions relevant to behavioral genetic and evolutionary-based analyses. It is concluded that (1) similar treatment of MZ twins results from their shared behavioral traits, rather than their matched appearance as some critics have claimed, and (2) physical resemblance does not predict close social relations between people in the absence of perceived behavioral similarities.

Paul Heggarty - What Role for Language in Uncovering the Human Past?
2013-04-24 00:00
Paul Heggarty: 4:00 PM Cotsen Institute Room A222From the Tower of Babel to the tales of the Aboriginal Dreamtime, we have long sought to account for our baffling multiplicity of tongues. Linguistic science itself was born out of this curiosity — and by now can look to our language diversity no longer as just an enigma to be solved, but also as a rich seam of data on the human past.
Or at least potentially so, for it remains a challenge to work out exactly what the linguistic record really tells us. Certainly, it cannot safely be read without the complementary perspectives of our other windows on the past. This talk surveys how linguistics might both enrich and learn from all its sister disciplines within the original ‘four field’ foundations of anthropology, not least archaeology and population genetics. In their data-sets, methods and analyses these disciplines all differ radically, but they are only all the more complementary for it, towards their common goal of uncovering what is, after all, the same, single human past.
Early attempts were bedevilled by false analogies and simplistic associations between languages, ‘cultures’ and ‘peoples’, engendering a generalised distrust of speculations on grand cross-disciplinary synopses. So I return here to first principles, to reconsider how it is that language can inform us of the past at all. Language is a ‘social animal’; it does not ‘just happen’ that language lineages spread, interact, diverge or converge, as if in a social, cultural and demographic vacuum. Rather, those outcomes are but the linguistic reflexes of processes at work far more generally, created by and acting upon the people and societies that speak those languages. These same processes leave their imprints in material culture and the bio-archaeological and genetic records too, so it is here that the link between our disciplines lies.
To be convincing and coherent, our respective scenarios need to match independently on three key levels: when, where and why. On each, I survey the main models and methods (both traditional and new) devised for setting our language lineages into their (pre)historical contexts. I assess proposed techniques for linguistic dating, and for locating the ancestral homelands of great language families. And on causation, I peel back the distorting impacts of the modern world to explore the past roles of technologies, trade and cultural networks, state organisation, conquest, subsistence regimes, demography and environment. Any such real-world cause must also be commensurate in scale with whatever linguistic effect it is invoked to explain.
Illustrations are taken from across the millennia and across the world, from individual case-studies to the broadest patterns and contrasts in the global linguistic panorama: hotspots and ‘deserts’ of language diversity; powerful convergence areas; and vast, deep-time language families such as Indo-European or Afro-Asiatic, driven by some great expansive and divergent processes, but which? I conclude with the most ambitious generalisations of all, and the furore surrounding them: farming/language dispersals, and the claims to reduce vast proportions of all human languages into great macro-families such as the putative ‘Amerind’ of the New World.

Jennifer Hahn-Holbrook - Is Postpartum Depression a Disease of Modern Civilization?
2013-04-29 00:00
Jennifer Hahn-Holbrook: University of California, Los AngelesPostpartum depression poses an evolutionary puzzle: it is extremely common, yet significantly reduces the reproductive fitness of both mothers and children. Why has natural selection failed to remove this trait? I will consider the hypothesis that postpartum depression represents a “disease of modern civilization” – that is, a byproduct of the dramatic cultural changes to motherhood that have occurred over the last century. This perspective predicts that postpartum depression will be more common in contexts where breastfeeding, diet, exercise, sleep, & alloparenting patterns diverge most dramatically from those of our Pleistocene ancestors. I will present cross-cultural, epidemiological, and experimental studies showing that postpartum depression is associated with early weaning, insufficient vitamin D due to limited sun exposure, diets deficient in essential fatty acids, and isolation from kin support networks, all of which diverge significantly from lifestyles typical throughout most of human evolution.

Bailey House - The ontogeny of population differences in human cooperation
2013-05-06 00:00
Bailey House: University of California, Los AngelesOne explanation for the diversity in cooperative behavior across human social groups is that our prosociality is motivated in part by learned cultural beliefs that vary substantially across societies, and which extend adaptations for cooperation between genetic kin and reciprocal partners. Reframing this idea as a developmental question about how culture shapes the emergence of cooperative behavior throughout human ontogeny, in this talk I present a series of cross-cultural studies that take a first step towards understanding how population differences in cooperation emerge across human development. In these studies of prosocial behavior, I explore the origins of population differences among children aged 3-14 years in a number of diverse societies. The results of this work suggest that human prosociality unfolds through a complex interaction between developmental stages, population membership, and the personal cost of helping. These results are consistent with models of human cooperation based on evolved cultural beliefs, but they also point to critical questions that must be addressed in future work.

Claire White - Evolutionizing Bereavement Research: Toward an Integrated Account of Human Grief
2013-05-13 00:00
Claire White : California State University, NorthridgeGrief is a universal reaction to the loss of a valued relationship partner. Two main evolutionary accounts of grief have been proposed. The first views grief as a by-product of an adaptive separation reaction that functions to aid unification in the temporary loss of a valued relationship partner. The second posits that grief is an adaptation that evolved to cope with the loss of a loved one by changing goals, signaling to others to enhance social support and reassessing one’s current behaviors, relationships and priorities. Despite the potential of evolutionary accounts to inform research, they have not been integrated into mainstream bereavement literature. This state of affairs is in part because evolutionary theories of grief lack theoretical clarity, empirical predictions and supporting evidence. The aim of this talk is to highlight these weaknesses and to begin to correct for them. The talk is divided into three parts. First, I critically evaluate the two leading evolutionary theories of grief. Second, I analyze the goodness-of-fit between the predictions generated from these two contrasting approaches and findings in bereavement research, including data from a series of studies that I have conducted. Third, and finally, I propose a new evolutionary account of grief that integrates existing theories by disaggregating the core symptoms after the experience of bereavement into evolutionarily meaningful subtypes.

Steven Stroessner - Confronting Threat When Safety Concerns are Paramount
2013-05-15 00:00
Steven Stroessner: Barnard College, Columbia UniversityMotivations are generally concerned with maintaining safety (prevention) or ensuring advancement (promotion) (Regulatory focus theory; Higgins, 1997). Four experiments examined whether information implying imminent threat would interact with regulatory focus to affect endorsement of stereotypes and stereotype-based policies. Because threatening information is more relevant to the safety goals of prevention-focused individuals than the advancement goals of promotion-focused individuals, endorsement of threat-relevant stereotypes was expected to increase under high threat but only for people operating under a under prevention focus. Support for this prediction was obtained in four distinct and socially important domains. In three experiments, prevention-focused individuals made judgments and endorsed policies consistent with stereotypes when threat was perceived to be high rather than low. In a fourth experiment in which the stereotypicality of the target was manipulated, only prevention-focused individuals were more likely to endorse scrutinizing a target stereotypically associate with danger under high threat conditions. Across the experiments, promotion-focused individuals tended to exhibit less stereotyping under high threat, suggesting that they were engaged in systematic processing under low regulatory fit. These results demonstrate that safety concerns produce vigilance toward threats in the social environment, but that responses to threat vary with its perceived imminence. Threat-relevant stereotypes are utilized when safety concerns are paramount.

Monique Borgerhoff-Mulder - Responding to Inequality: Cooperation, Kinship and Witchcraft in Mpimbwe, Tanzania
2013-05-20 00:00
Monique Borgerhoff-Mulder: University of California, DavisWhile the causes, transmission and consequences of material and social inequality are well studied in the social sciences, the ways in which people respond to inequality are less clear. As evolutionary social scientists we know that humans show a strong aversion to inequality, but we have little understanding of how individuals respond behaviourally to disparities in material, social and relational wealth. In this talk I present data from the Pimbwe, a Bantu forager-horticulturalist population in Tanzania undergoing rapid social change and escalating material inequality, to show how both witchcraft accusations and social networks of exchange are patterned by wealth differences. Specifically cooperation among unrelated and related individuals is least pronounced amongst the wealthiest individuals. This observation is used to start theorizing how inequities might favor or disfavour cooperation. A better understanding of such dynamics is important, given the escalating levels of inequality worldwide, consequential on the neoliberal policies associated with globalization.

Matthew Gervais - Mapping an egalitarian hierarchy: relational economic games tap RICH norms of helping and leveling in a Fijian village
2013-06-03 00:00
Matthew Gervais: The University of California, Los AngelesExperimental economic games have shed significant light on human population variation in social behavior. However, most of these games have involved anonymous dyadic recipients, limiting their external validity beyond fleeting pairwise interactions. Yet enduring relationships within large social networks are arguably the cradle of human uniqueness and remain the cornerstone of human adaptation across societies. Mapping the mechanisms that structure social behavior within human communities will require methods that have the virtues of economic games – including incentivized behavior, and replicability and comparability across populations – but which integrate multiple identifiable recipients and thereby tap Recipient Identity-Conditioned Heuristics (RICHs) such as direct and indirect reciprocity, trait- and state-based notions of fairness, and kinship norms. This talk describes three “relational” economic games that integrate recipient identities and other-other tradeoffs, and reports their validation in a study of male social relationships in a Fijian village. The three games, an Allocation Game, a Taking Game, and a Costly Reduction Game, involve monetary decisions made across a photo array of other villagers. Levels of both altruism and spite in these games are higher than those documented using dyadic anonymous games in neighboring villages. Recipient need is the major driver of giving and refraining from taking, while the wealthiest villagers are the mostly likely to be reduced at a cost, especially if they lack “Chiefly” character. Such need-based giving and leveling are hallmarks of human egalitarianism, and are well attested to in Fijian ethnography. Moreover, dyadic attitudes such as love, respect, hate, and fear partially mediate helping and punishing others, illuminating the psychological processes that regulate Fijian relationships. Relational economic games thus hold promise for mapping population variation in RICH norms and the mechanisms supporting cooperation within human communities, significantly advancing the toolkit of a scientific anthropology.

Lee Cronk - Our cultural immune system: Toward a theory of culture’s influence on behavior
2013-09-30 00:00
Lee Cronk: Rutgers University Department of AnthropologyAnthropologists are rarely able to predict when a culture trait will influence behavior and when it will not. The theory of gene-culture coevolution leads to the prediction that we should have something akin to an immune system for culture that helps us make adaptive decisions regarding which culture traits to resist and which to allow to shape our behavior. Understanding our cultural immune system will require us to define culture in a way that separates it from behavior, consider the impacts of individual culture traits on behavior rather than treating culture as an undifferentiated whole, and focus on culture traits that have clear behavioral referents. One way to examine the impacts of individual culture traits on behavior is to transfer them from the societies in which they originated to new ones and then assess their impacts on behavior. I have used this technique in a series of studies using a Maasai gift-giving norm. The impact of the norm on behavior is revealed through experimental games framed in terms of the norm played by both Maasai men and American college students. The results suggest that even unfamiliar social coordination norms may easily influence behavior across societies but that this effect depends crucially upon exactly how the norm is framed.
