John Novembre - Spatial population structure and the genetic basis of adaptation in human populations
2009-11-16 00:00 (America/Los_Angeles)
John Novembre: UCLA Department of Ecology and Evolutionary Biology & Interdepartmental Program in BioinformaticsNovel technological developments are providing an unprecedented opportunity to study the geographic distribution of human genomic diversity. This information has been leveraged to study population structure and interrogate signatures of natural selection. In this talk I will review emerging results from geographic studies of human genetic variation that provide insights into 1) human population structure; and 2) the genetic basis of the response by human populations to recent selective pressures. http://www.bec.ucla.edu/NovembreTalk.pdf

David Liu - Asking
2009-11-23 00:00
David Liu: UCSD Department of PsychologyMuch research and debate around theory of mind (the ability to attribute mental states to actions) have revolved around whether X have a theory of
mind. X might be 3-year-olds, infants, children with autism, chimpanzees, rhesus macaques, and so forth. I will argue that the better question is what aspects or types of theory of mind are used by X. Numerous studies have shown that children develop different components or aspects of mental-state understanding at different ages, and nonhuman animals demonstrate some components of mental-state understanding in certain situations. Research in my lab has shown that children with different developmental disabilities and typically-developing children from different cultures have shared and nonshared trajectories in their developmental progression of understanding different mental states. In addition, we have discovered different neural circuitries associated with reasoning about different mental states. Our findings provide a framework for understanding similarities and differences in mental-state understanding across different human populations and different species.

Catherine Reed - The Role of Specialized Body Processing for Embodied Social Perception
2009-11-30 00:00
Catherine Reed: Claremont-McKenna College Department of PsychologySocial psychologists have embraced the tenants of embodied cognition to explain how we understand the emotions of others. They claim that the reinstantiation of previous sensorimotor experience during emotional and social information processing is an essential process for understanding othersâ€™ emotions (e.g., Neidenthal, Barsalou, Winkielman, Krauth-Gruber, & Ric, 2005). In this talk I suggest that current models of embodied emotion are missing the necessary body-processing mechanisms from which the simulations of emotional experience operate. Further, if one cannot create the basic correspondences between another personâ€™s body and oneâ€™s own then one cannot engage in the appropriate simulation process which can lead to social-emotional deficits such as those observed in autism spectrum disorders.

Adriana Galvan - Adolescence as a developmental period of increased risk-taking and reward sensitivity: Insights from Neuroimaging
2010-01-04 00:00
Adriana Galvan: UCLA Department of PsychologyAdolescence is a developmental period marked by heightened sensitivity to reward and increased proclivity towards risk-taking behavior. These behavioral changes are paralleled by significant developmental changes in neural circuitry related to reward processing and cognitive control. In this talk, I will describe recent data on adolescent brain development, propose a neurobiological model to describe adolescent risk-taking behavior, and provide a framework for how these neuroimaging insights might be used for intervention and prevention of harmful risk-taking behaviors during adolescence.

Lynn Fairbanks - Genetic, Maternal and Life History Influences on Sociability in Vervet Monkeys
2010-01-11 00:00
Lynn Fairbanks: UCLA Department of Psychiatry & Biobehavioral SciencesThe ability to form and maintain social relationships is an important attribute that has broad implications for health and fitness in humans and nonhuman primates. In this presentation, I will describe the development of a quantitative measure of sociability in the Vervet Research Colony, a multigenerational pedigreed colony of vervet monkeys, and present evidence for the consistency, specificity and heritability of sociability as a trait. Mean Sociability scores are affected by life history variables, including age, sex, male emigration, and the presence of infants, but longitudinal analysis indicates that individual differences are maintained over time and across life stages. Because of the importance of matrilineal social relationships in primate societies, including the social â€˜inheritanceâ€™ of dominance rank for females, there is a possibility of maternal environmental effects on sociability. To account for this, we include a component for shared maternal environment in a statistical genetics analysis to identify the contributions of genetic and maternal effects on trait variation, using the extended pedigree. The results indicate there are strong genetic contributions to variation in Sociability scores for both males and females, with maternal effects accounting for a smaller but statistically significant portion of the variance for females but not for males. The final part of the presentation will provide evidence for effects of variation in sociability on male reproductive success.

Tim Waring - Do Ethnic Divisions Restrict Sustainable use of Natural Resources? A case study from Tamil Nadu
2010-01-15 00:00
Tim Waring: UC Davis Department of Environmental Science and PolicyNumerous scholars have shown that increasing ethnic diversity is correlated with reduced cooperation and fewer public goods. This result has significant implications for development policy, lowering expectations for success in public infrastructure investment with ethnically diverse populations. I present evidence that ethnic hierarchy may be driving the observed effect of ethnic diversity. Ethnic hierarchy is naturally confounded with ethnic diversity because hierarchy cannot logically exist without diversity and because diversity without hierarchy may be exceedingly rare. To determine which factor is a greater constraint on cooperation, I tested the strength of both ethnic diversity and ethnic hierarchy as cooperative limitations using public goods experiments with caste groups in South India. I show that the effect of ethnic diversity is neutralized when relatedness between individuals is taken into account. However, ethnic hierarchy remains severely damaging to public goods cooperation, when all variables are accounted for, and is a required variable for any explanatory model. Moreover, the influence of social momentum is significant. I find that the initial behavior in the game determines the long run outcome, while the cooperative momentum is carried forward in the round-by-round decisions.http://www.bec.ucla.edu/TimWaringSlides.pdf

Nameera Akhtar - Children's learning from third-party interactions
2010-01-25 00:00
Nameera Akhtar: UCSC Department of PsychologyParents and researchers in Western middle-class societies emphasize dyadic interactions and teaching children new skills directly. This emphasis obscures the fact that young children can learn much through observation of othersâ€™ interactions. I will describe the results of several recent studies of young childrenâ€™s learning from third-party interactions. Some of the studies examine learning novel words through overhearing others involve the learning of novel actions (imitative learning). The findings indicate that learning from third-party interactions is a robust skill seen in children as young as 18 months, and suggest that this type of learning may rely on emerging social-cognitive skills that enable the child to imagine herself in the third-party interaction.

Eric Vilain - Gaynomics: The Biology of Sexual Orientation
2010-02-01 00:00
Eric Vilain: Professor of Human Genetics, Pediatrics and Urology Director, Center for Gender-Based Biology, Chief, Medical Genetics – Department of Pediatrics, David Geffen School of Medicine at UCLAHuman sexual orientation, oneâ€™s preference for male or female sexual partners, is a largely stable behavioral trait with a significant genetic component. It is a highly sexually dimorphic trait, and as such an interesting model for brain sexual differentiation.
There is much uncertainty about the factors that shape sexual orientation. Although many studies have helped to explain the experience of lesbian, gay, and bisexual (LGB) individuals, empirically supported explanations for the development of an LGB identity are lacking.
Often the media hypes the results of biological research on sexual orientation. Yet, the reports on biological findings are filtered through the journalistsâ€™ understanding of the science and at times are misrepresented. Further, parties who are both for and against the rights of sexual minorities reinterpret these media reports. This can make it difficult to sort fact from fiction.
The purpose of this presentation is to provide an overview on what the biological research has shown in regards to sexual orientation, to assess the current state of the research, and to highlight strengths/limitations of this research. To accomplish this, four main areas will be considered.
Hormones: Research has investigated whether prenatal hormones affect sexual orientation. Although hormones have an impact on behavior, only gross hormonal variations seem to affect sexual orientation.
Anatomical associations: Despite media attention, evidence that non-heterosexual individuals have distinctive anatomical features is far from conclusive. In regards to the anatomical association studies, only non-right handedness and specific anatomical features of the hypothalamus have a consistent relationship with a non-heterosexual orientation.
Birth order: A consistent finding is that having an older brother increases the odd of male homosexuality. Differing theoretical viewpoints on this issue will be discussed.
Genetics: Finally, the most promising evidence for biological influences comes from recent advances in the field of genetics. The validity of studies using â€œfamily treesâ€ and the potential role of the expression of genes on sexual orientation will be discussed. Finally, twin studies will be reviewed, as well our own epigenetic data on twin pairs discordant for sexual orientation.

Karen Bales - Neurobiology of parenting in monogamous species
2010-02-08 00:00
Karen Bales: UC Davis Department of PsychologyIn socially monogamous mammals like humans, many individuals such as mothers, fathers, and alloparents often display parenting behaviors. While the hormonal and neural basis of maternal care has been well-studied, both fathering and alloparenting remain more mysterious. Studies from prairie voles and titi monkeys, both monogamous mammals, implicate oxytocin, vasopressin, and glucocorticoids in the regulation of these behaviors. While these hormones may facilitate parenting, developmental data also suggest that the exposure to infants itself changes the brain in a long-term fashion in both males and females. I will discuss what is known about the neurobiology of parenting in males, females, and alloparents, and what opportunities and challenges exist in studying these topics in humans

Peter Kim - The Manifestation of Mob Mentalities
2010-02-22 00:00
Peter Kim: USC Department of Management and Organization, Marshall School of Business, University of Southern CaliforniaThroughout history, people have faced the question of how best to respond to a wide range of alleged and/or actual transgressions. A fundamental uncertainty, in this regard, is whether our reactions to such transgressions would differ depending on whether we respond to them as individuals or as groups. This question deserves particular scrutiny given that transgressions can often affect multiple people, the fact that our reactions to such transgressions are rarely made in isolation, the frequency with which these assessments may be made at a collective level, and the potential implications of such assessments for social and organizational life. However, the literature offers little guidance on these issues, given that previous research has focused primarily on the reactions of individuals. The present inquiry seeks to address this limitation: a) by investigating how individuals and groups might differ in their reactions to alleged transgressions, b) by determining the conditions under which such differences would arise, c) by identifying some underlying mechanisms for these differences, and d) by exploring the ways in which transitions between individual and group modes of evaluation may affect these assessments.http://www.bec.ucla.edu/PeterKimPaper.doc

Russell Gray - The Pleasures and Perils of Darwinizing Culture (with Phylogenies)
2010-03-01 00:00
Russell Gray: University of Auckland Department of PsychologyCurrent debates about â€œDarwinizing cultureâ€ have typically focused on the validity of memetics. In this talk I will argue that meme-like inheritance is not a necessary requirement for descent with modification and suggest that an alternative, and more productive, way of Darwinizing culture can be found in the application of computational phylogenetic methods. The benefits of this approach will be illustrated by drawing on my recent work examining linguistic and cultural evolution in the Pacific. I will discuss problems that reticulate evolution allegedly cause phylogenetic analyses and suggest ways in which these problems can be overcome. Throughout I will emphasize that most debates about cultural phylogenies can only be settled by empirical research rather than armchair speculation.http://www.bec.ucla.edu/R.Gray1.pdf

Peter Fashing - Behavioral ecology of East African primates: Costs and benefits of group living in colobus and gelada monkey societies
2010-03-08 00:00
Peter Fashing: CSU Fullerton Department of AnthropologyGiven that animal societies represent a collection of genetically selfish individuals that have come together to live and reproduce as part of a group, conflicts over the allocation of resources essential to survival and reproduction must routinely occur. For groups to remain stable over evolutionary time, these conflicts must be resolved to the satisfaction of all group members â€“ that is, the benefits of group life must outweigh the costs. In this talk, I will describe my past, present and future research into the costs and benefits of group living for individuals and groups of wild primates, including colobus and gelada monkeys, in East Africa, and discuss how insights gained from non-invasive, observational sampling of primate behavior and ecology can shed light on the evolution of group living in humans and other animals. http://www.bec.ucla.edu/Fashing1.pdf

P. Jeffrey Brantingham - Burglars, Bangers and Bombers: The Behavioral Mechanisms Underlying Repeat Victimization
2010-03-29 00:00
P. Jeffrey Brantingham: UCLA Department of AnthropologyIt is well known that victims of both violent and property crime experience an increased risk of being victimized again, especially during a brief interval of time following the initial event. Ethnographic evidence suggests, in the case of property crime, that offenders seek out previous targets to replicate previous successes. In the case of violent crime, by contrast, retribution plays an important role in ramping-up and sustaining cycles of violence. Self-exciting point process models are used to study the time-course of burglary in Los Angeles, violent acts and reprisals between rival gangs in Los Angeles and insurgent attacks in Iraq. Self-excitation appears to be a generic statistical structure for crime hotspot formation across most, if not all types of crime.
This work is a collaborative effort with Andrea Bertozzi, George Mohler, Martin Short and Erik Lewis (UCLA Math), as well as George Tita (UC Irvine Criminology) and the Los Angeles Police Department. The work was supported by the US National Science Foundation.
*(Co-Sponsored by the Cotsen Institute of Archaeology at UCLA)

Peter Gray - The Descent of Dad's Sexuality
2010-04-05 00:00
Peter Gray: University of Nevada-Las Vegas Department of AnthropologyHow does fatherhood impact men’s sexuality? In this presentation, we review some of the core facets of paternal sexuality. Cross-cultural patterns of fertility beliefs suggest that a physiological basis of paternity is usually recognized, but without a link to mid-cycle ovulation. Male anatomy and semen components are optimized for successful reproduction in the face of relatively low sperm competition. Following conception, cross-cultural variation in sexual practices during gestation exists. In some societies, men are expected to engage in frequent intercourse to help foster a fetus’ growth, whereas in others intercourse quickly plummets following recognition of a pregnancy. Possible explanations for this variation are suggested. Postpartum declines in sexuality are robust in meta-analysis of western societies and cross-culturally, but also responsive to a number of variables. The resumption of sexual activity within a couple can be best understood with reference to reductions in female libido, breastfeeding, the availability of alternative sexual partners (e.g., in polygynous marriages), marital quality and partners’ ages. The human propensity to have sex in private also poses challenges to the resumption of sexual activity, especially in light of social sleeping arrangements. Implications and directions for future research are suggested, including the call for researchers and analysts to consider reproductive state (e.g., postpartum) more formally in sexuality data, and for more inclusive samples (e.g., gay fathers and stepfathers) addressing paternal sexuality.http://www.hup.harvard.edu/catalog/ANDMAN.html

Tom Griffiths - Effects of Inductive Biases on Cultural Transmission
2010-04-12 00:00
Tom Griffiths: UC Berkeley Department of Psychology and Group Major in Cognitive ScienceLearning a language, a concept, or a social norm all require making an inductive inference, going beyond the data provided by the behavior of other people. Such inferences are underdetermined by the available data, allowing people’s biases to influence the conclusion that they reach. These inductive biases reflect the expectations that people have about which hypotheses are most likely to account for the data they observe, and the factors that make it easier to learn some languages, concepts, and norms rather than others. I will present a combination of theoretical results and laboratory experiments demonstrating that inductive biases can have a significant effect on the changes that information undergoes when it is passed from one person to another. By simplifying the process of cultural transmission down to a “diffusion chain” along which information is passed, we can examine how the inductive biases of individual agents influence the outcome of this transmission process. Assuming that the agents passing information are rational Bayesian learners, we can prove that over time the information they transmit will be transformed into a form more consistent with their inductive biases. Laboratory experiments in which diffusion chains are constructed from human participants bear out this prediction, with experiments in which a sequence of people learn from data generated by other people or reconstruct information from memory producing results that reflect their inductive biases. I will discuss the implications of these results for understanding cultural evolution more generally, as well as for identifying the circumstances under which we can expect knowledge to accumulate over time.http://cocosci.berkeley.edu/tom/papers/ilreview.pdf

Justin Wood - The Evolutionary Origins of Action Comprehension
2010-04-19 00:00
Justin Wood: USC Department of PsychologyAs social creatures, we wake up every morning to a dizzying array of actions from allies and competitors, in contexts that include cooperation, resource competition and parental care. Some actions are intentional, motivated by either distal or proximal goals; some are accidental, but nonetheless result in similar consequences. How do humans comprehend such actions, and are the mechanisms that subserve this ability uniquely human or shared with other species? In this talk, I present evidence that three nonhuman primate species (cotton-top tamarins, rhesus macaques, and chimpanzees), representing the three major groups (New World monkeys, Old World monkeys, and apes) comprehend others’ actions in the same way as human infants and adults. These results illuminate the evolutionary origins of a primary socio-cognitive ability and help distinguish between competing models of action comprehension in humans.http://www.bec.ucla.edu/JustinWood.pdf

Dario Maestripieri - Post-Copulatory Sexual Selection and Female Mating Vocalizations in Primates
2010-04-26 00:00
Dario Maestripieri: University of Chicago Professor of Comparative Human Development, Evolutionary Biology, Neurobiology, and PsychiatryPost-copulatory sexual selection operates through two main mechanisms: sperm competition and post-copulatory female choice. Little is known about the role of female behavior in inciting sperm competition or in the expression of post-copulatory choice. Little is also known about signals that occur after, rather than before, mating. The vocalizations that primate females give shortly after mating may be sexually selected signals that play an important role in both sperm competition and post-copulatory female choice. In recent papers, we have argued that female copulation calls have two immediate functions: to encourage mating attempts by other males and to increase mate guarding by the consort male. These vocalizations may have evolved under the selective pressures of risk of infanticide and sperm competition. When male mate guarding is effective, copulation calls allow females to concentrate paternity in dominant males and benefit from their protection against the risk of infanticide. When mate guarding is ineffective, copulation calls bring genetic benefits to females through facilitation of sperm competition. In this seminar, I will present a quantitative model in which variation in female promiscuity associated with social or ecological factors affects the extent to which dominant males can monopolize females and predicts female tendency to use copulation calls in conjunction with mating. The model predicts that in species with little female promiscuity, copulation calls should be rare and occur only after mating with dominant males. In species in which females are highly promiscuous, copulation calls should be frequent and occur after mating with any males regardless of their dominance rank. Consistent with the model, I will present data showing that female copulation calls are rare or absent in primate species in which male infanticide does not occur and sperm competition is absent or weak, whereas variation in female promiscuity in species in which male infanticide or sperm competition occurs accurately predicts the extent to which mating is accompanied by copulation calls. I will also present behavioral data from captive baboons showing that female copulation calls are most likely to occur after mating with dominant males and are effective in encouraging post-copulatory mate guarding.http://www.bec.ucla.edu/DarioPaper.pdf

Edward Slingerland - Why do Humanists Hate Vertical Integration?
2010-05-03 00:00
Edward Slingerland: University of British Columbia Department of Asian Studies, Canada Research Chair in Chinese Thought and Embodied CognitionCalls to “vertically integrate” (Tooby & Cosmides) or achieve “consilience” (E.O. Wilson) between the sciences and the humanities have, for the most part, been received with a great deal of hostility by humanists. This talk explores some of the reasons–good, bad, and unavoidable–for this hostility, and sketches an outline of what might profitably be called a “second wave” of consilience, one that would help to bring about a more amicable relationship between the “two cultures.”http://www.bec.ucla.edu/EdSlingerland.pdf

Eric Alden Smith - Large-Scale Cooperation in Small-Scale Societies
2010-05-10 00:00
Eric Alden Smith: University of Washington Department of AnthropologyCollective action with low relatedness (large-n, low-r cooperation) is a common feature of human societies, in marked contrast to patterns in other species. This is particularly puzzling for small-scale societies of foragers and horticulturalists, where formal social institutions to enforce collective action are weak or absent. There is considerable disagreement regarding the evolutionary basis of such forms of collective action; some are convinced they can be explained via standard forms of mutualism, reciprocity, and coercion supplemented by reputation mechanisms, while others insist that various forms of cultural group selection are required. This debate has been protracted, and progress in our understanding of the issues appears stymied. I argue that progress can be made, but will require carefully targeted empirical evidence from naturalistic settings, particularly concerning the distribution of costs and benefits among collective action participants. I focus here on small-scale societies, and pinpoint areas in which empirical evidence could be particularly helpful. These include:
1) What are the payoff structures for empirically common forms of collective action?
2) How great is reproductive skew within groups, and what are its individual-level and institutional correlates?
3) At what frequency do groups with greater amounts of collective action prevail demographically?
I discuss ethnographic variation in Native North America to explore what patterns these phenomena might take. However, convincing answers to these questions will require carefully tailored analyses of new or existing data.http://www.bec.ucla.edu/SmithPaper1.pdf

Doug Kenrick - How the Mind Warps: Evolution and Social Cognition
2010-05-12 00:00
Doug Kenrick: Arizona State University Department of PsychologyThe human mind processes information in a famously selective and shockingly biased way. Who and what do we select for attention, encoding, and retrieval, and how, why, and when do we distort certain kinds of information in certain ways and not others? My colleagues and I have been studying how basic cognitive processes are influenced by activating fundamental human motivations such as self-protection or mating goals. We’ve found several domain-specific cognitive enhancements, decrements, and distortions: we stare at, but fail to remember, certain people in certain circumstances, we look away from, yet remember, other people in other conditions, and sometimes we differentiate members of out-groups who are normally blurred together in our memories. These motivated biases are anything but random and senseless. Instead they predispose adaptive context-sensitive decisions about whether to conform or show off, whether to fight or flirt, whether to take financial risks, and so on. At a deeper level, these biases make functional sense when considered in light of broader theoretical developments at the interface of evolutionary biology, comparative anthropology, and cognitive science. http://www.bec.ucla.edu/KenrickPaper1.pdf

Elizabeth Pillsworth - Is Female Choice Overemphasized in the Evolutionary Psychology of Human Mating? Evidence from the Shuar of Ecuador
2010-05-17 00:00
Elizabeth Pillsworth: CSU Fullerton Department of AnthropologyDarwin’s theory of sexual selection emphasizes the role of female mate choice in shaping male morphology and behavior. In evolutionary psychology, the model of female choice has served as one organizing feature of research on human mating. However, in many human societies women are reported to have very little influence over their own mating decisions; rather, parents or other kin often control the marriage decisions of daughters. This has led to the claim by some that female choice has been overestimated as a selective force in human evolution, based upon the evolutionarily novel context of modern Western sexual practices. I will present data from the Shuar, a hunter-horticulturalist society in the Amazon basin of Ecuador, to highlight the ways in which women exert mate choice within a paternalistic and highly controlling environment, and demonstrate that choice need not be “free” to have an evolutionary impact.

Carlos Navarrete - Sexual Selection and the Psychological Architecture of Race Prejudice
2010-05-24 00:00
Carlos Navarrete: Michigan State University Department of Psychology & Evolution, Ecology, and Behavior ProgramIntergroup aggression perpetrated by men has been a persistent feature of human societies for centuries, and may have been common enough over evolutionary time to have allowed selection to shape the neural circuitry underlying the psychology of prejudice. Because intergroup aggression poses different adaptive challenges for men and women, the psychological adaptations that operate to cope with such threats may differ between the sexes as well. Because racial categories are often mentally represented as group-like entities, modern race bias should be understandable within this general framework. Results from several studies are consistent with this perspective, and show that (a) race bias is primarily directed at male exemplars of racial-outgroups, (b) men are more likely to be aggressively prejudiced than women, and (c) women are more likely to be fearfully prejudiced than men, particularly during the fertile phase of the menstrual cycle. Illustrations of how these systems may be operative in political attitudes and voting preferences for Barack Obama are presented. These results are consistent with the notion that the psychology of intergroup prejudice is generated by different psychological systems between men and women.

Quentin Atkinson - The Cultural Evolution of Human Languages
2010-06-01 00:00
Quentin Atkinson: University of Oxford Institute of Cognitive and Evolutionary AnthropologyLanguages, like species, evolve. Words and phrases compete for our favour in a struggle for existence that is analogous to natural selection. Words that survive are passed on from generation to generation in a process of descent with modification. This process has generated the thousands of languages we see in the world today. In this talk I will discuss how methods and theory from evolutionary biology can be applied to linguistic data to shed light on the ancestry of extant languages and the processes that have given rise to modern human language diversity.

Aaron Blackwell - Life history, immune function, and helminths: The behavioral and immunological ecology of the Shuar of Ecuador
2010-09-27 00:00
Aaron Blackwell: UCSB Department of AnthropologyThe Shuar are a large and semi-autonomous indigenous group from the Amazonas region of Ecuador. Most Shuar subsist on a mixture of foraging and horticulture, but increasingly Shuar in many areas are becoming integrated with market economies. This talk presents fieldwork conducted amongst the Shuar between 2005 and 2009, with comparative data from the Shiwiar of Ecuador, non-indigenous Ecuadorian colono children, the Tsimane of Bolivia, and the 2005-2006 U.S. NHANES. I examine how growth and immune function are affected by market integration, household composition, and changes in pathogen exposure. Compared to the more traditionally living but closely related Shiwiar, Shuar show a higher prevalence of growth stunting. Between individuals, growth stunting is related to markers of immune activation, particularly as related to helminth infection. Biomarkers of helminth infection are associated with poorer growth in children, lower stature in adults, and decreases in inflammatory biomarkers. These results suggest that infection with parasites, such as helminths, may have hidden costs associated with changes in the allocation of resources between the competing demands of immune function and growth. In addition, higher biomarkers of helminth infection are associated with the presence of additional children in a household, suggests children in large families may face increased pathogen transmission as well as potential competition for limited parental resources.http://www.bec.ucla.edu/BlackwellPaperFinal.pdf

Uri Gneezy - Gender differences in preferences
2010-10-04 00:00
Uri Gneezy: UCSD Rady School of Management Arthur Brody Endowed Chair in Management Leadership, Professor of Management and StrategyIn this talk I will discuss some recent findings regarding gender differences in economic experiments. The discussion will focus on gender differences in competitiveness, but will also touch on differences in risk preferences and social preferences. I will also speculate on the source of these differences, as well as on their implications.http://www.bec.ucla.edu/GneezyPaper.pdf

Erol Akcay - Evolution of motivations and behavioral responses: Integrating the proximate and ultimate causes of behavior
2010-10-11 00:00
Erol Akcay: University of Tennessee National Institute for Mathematical and Biological Synthesis (NIMBioS)There is extensive work on the evolutionary causes of social behaviors, but integration of this theory with the proximate mechanisms of behavior has lagged behind. Here, I will present a new modeling approach to achieve such integration. The model rests on goal-oriented motivations, or preferences, as the proximate determinants of behavior and describes the dynamics of a social interaction at the behavioral time scale. During these behavioral dynamics, individuals can respond to each other’s actions, and these responses ultimately drive the evolution of the proximate motivations.
We first apply this framework to the question of other-regarding motivations. We find that other-regarding motivations can evolve even when there is complete conflict of interests between the individuals, and in the absence of group- or kin-selection. We then turn our attention to the evolution of conformist motivations, and explore conditions that facilitate their evolution. Finally, we generalize our framework to include the joint effects of behavioral responses trough proximate mechanisms and selection in structured populations. The resulting model illuminates the interplay between behavioral responses and relatedness in the evolution of social behaviors. In particular, we find that behavioral responses can facilitate the evolution of group-optimal behaviors, and result in transitions between levels of selection.

Thomas Flamson - Encryption Theory: The evolution of humor as an honest signal
2010-10-18 00:00
Thomas Flamson: Santa Monica College Department of Earth Science / UCLA Department of AnthropologyThe Encryption Theory of Humor proposes that humor evolved as a means of signaling similarity in locally variable personal features in order to facilitate assortment with the most compatible peers within the local group. It claims that a necessary component of humorous production is the presence of multiple, divergent understandings of speaker meaning, some of which are dependent on access to implicit information. Because of this dependence, only those listeners with access to this background knowledge can “decrypt” the implicit understandings, which further entails the inference that the speaker shares that access. This provides a channel for the honest signaling of personal features, which enables within-group assortment for compatible long-term interaction partners such as friends or mates.
This talk will present a range of data supporting various aspects of this hypothesis, obtained both through online studies with literate Western participants, and ethnographic observation and studies conducted in rural northeastern Brazil. It will be shown that (a) prior knowledge interacts with information provisioning to impact individual humor preferences, (b) these preferences reflect closeness in real-world social networks, and (c) evaluations of the sense of humor of other individuals also reflect social closeness. These findings support the hypothesis that humor evolved as a subjective, interdependent signaling system for compatibility matching, and not simply as an index of objectively-evaluated traits, such as intelligence.

Robert Wayne - Evolution and diversification of the domestic dog
2010-10-25 00:00
Robert Wayne: UCLA Department of Ecology and Evolutionary BiologyThe domestic dog is one of our most remarkable inventions. The behavioral and functional diversity of the dog far surpasses that of its wild progenitor, the gray wolf. Similarly, in size and proportion, dogs exceed the diversity of the entire carnivore order. The dog genome project and recent advances in biotechnology have enabled a new understanding of the process of domestication and diversification. I discuss our recent molecular findings concerning the origin of the dog and present a new evolutionary tree of dogs that leads to a better understanding of the nature of artificial selection and how it has shaped the diversity of our closest animal companion.
*(Co-Sponsored by the UCLA Center for Society and Genetics)

James Holland Jones - Contact Networks, Models of Infectious Disease, and Epidemic Simulation
2010-11-01 00:00
James Holland Jones: Stanford University Department of AnthropologyInteraction networks shaped by social processes constitute the substrate on which various phenomena of interest to evolutionary anthropologists and human biologists occur. Examples of such phenomena include epidemics, diffusion of ideas or information, and the exertion of social and political influence. Understanding the structure of network formation is thus crucial to our understanding of how relational human interactions mediate key biosocial outcomes. Research in this area has been hampered by an acute lack of (1) high-quality data on the formation and structure of contact networks and (2) realistic models for the social processes that shape networks. In this talk, I present results from two recent papers that address these deficits. First, I will show the consequences for epidemic behavior of networks that exhibit strong community structure. Such hierarchical social interaction is ubiquitous in human populations, making it important that we understand the behavior of epidemics in community-structured networks. We show that the degree of community structure has a pronounced impact on the final size of simulated epidemics, even in the absence of any changes in the basic reproduction number of the epidemic. We use our results to design network-informed vaccination strategies that generally outperform comparable existing strategies.
Our finding that community structure can affect epidemic behavior qualitatively highlighted the acute lack of high-quality data on network structure for relations relevant to disease transmission and motivated our collection of such data. Using Wireless Sensor Network (WSN) technology, we measured the temporal dynamics of close-proximity interaction networks during a typical school day in a high school in the San Francisco Bay Area. Participants wore small wireless sensors which send and receive radio signals to and from other sensors nearby. This technology allowed us to collect dynamic contact network data with unparalleled precision. At a 94% coverage, we collected 762,868 CPIs at a maximal distance of 3 meters among 788 individuals. The data revealed a high density network with typical small world properties and a relatively homogenous distribution of both interaction time and interaction partners among subjects. Computer simulations of the spread of an influenza-like disease on the weighted contact graph are in good agreement with absentee data during the most recent influenza season. Analysis of targeted immunization strategies suggested that contact network data are required to design strategies that are significantly more effective than random immunization. Immunization strategies based on contact strength were generally most effective and the effects were seen most acutely at high vaccination coverage.

Michael Alvard - Social structure, cultural kinship, and cooperation among the Lamalera whale hunters of Indonesia
2010-11-08 00:00
Michael Alvard: Texas A&M University Department of AnthropologyThe human ability to form large, coordinated groups is among our most impressive social adaptation. Larger groups facilitate synergistic economies of scale for cooperative breeding, economic tasks like group hunting, and success in conflict with other groups. In many organisms, genetic relationships provide the structure for sociality to evolve via the process of kin selection, and this is the case, to a certain extent, for humans. But assortment by genetic affiliation is not the only mechanism that can bring like-minded people together. Affinity based on symbolically mediated and socially constructed identity or cultural kinship structures much of human sociality.
This talk will examine how genetic kinship and various kinds of cultural kinship–affinal, descent, moiety–structure the network of cooperating whale hunters in the village of Lamalera, Indonesia. The people of Lamalera are among the last subsistence whale hunters on the planet. The village of 1,200 people rely largely on the sperm whales, other marine mammals, manta and other rays that the community’s men cooperatively hunt from a fleet of traditional, 11m long, whaling vessels called tèna.
Using data from 853 hunts, network analyses show that each mechanism of assortment produces characteristic networks of different sizes, each more or less conducive to the task of hunting whales. The results are discussed in the context of the evolution of cooperation and group identity.
