Center for Behavior, Evolution, and Culture

Steven J. Heine - Positive Self-Views, East and West
2012-10-22 00:00 (America/Los_Angeles)
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.

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.

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.

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.

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.

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

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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

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

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.

Anne Kandler - Analysing Language Shift: the Example of Scottish Gaelic
2012-02-13 00:00
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.

Nga Nguyen - Behavioral biology and endocrinology of wild baboons and geladas in East Africa
2012-02-06 00:00
Nga Nguyen: CSU FullertonMaternal care is the most significant measure of successful adaptation among female mammals. Understanding the predictors of individual differences in offspring care is a major objective of mammalian reproductive biology. In this talk, I will evaluate the impact of maternal and infant characteristics, maternal hormones, and friendships with males on the mother-infant relationship in wild baboons, and discuss the potential fitness consequences of variation in these variables for mothers and infants. I will also discuss the results of my more recent research on reproductive biology in a wild gelada monkey population inhabiting one of the coldest and highest elevation environments of any non-human primate

Heather Watts - Influences of social behavior on survival and reproduction in birds and mammals
2012-01-30 00:00
Heather Watts: LMUPatterns of survival and reproduction are known to be influenced by prevailing environmental conditions. In this talk, I will draw from my research on gregarious mammals and birds to examine how the social environment can affect these two components of fitness. First, I will discuss how social status, group size and maternal support influence survival and reproduction in the spotted hyena (Crocuta crocuta), a large carnivore that lives in complex social groups much like those of cercopithecine primates. Second, I will present my recent research investigating the effect of social cues on reproductive timing in the pine siskin (Spinus pinus), a nomadic North American finch with a flexible breeding schedule. Throughout, I discuss what these findings tell us about the evolution of behavior in these species.

Keise Izuma - Social Reward Based Decision-Making in Humans
2012-01-23 00:00
Keise Izuma: Cal TechHuman behaviors are influenced by the concern for social reputation (e.g., how other people think of us). It is well known in behavioral sciences that individuals tend to behave in a more egoistic manner under guaranteed anonymity, whereas less anonymous situations (e.g., the presence of others) increase pro-social behaviors. These observations are consistent with theoretical studies suggesting that reputation might be a key mediator of aspects of altruistic behavior that are uniquely human. Thus, reputation may be a unique and important aspect of our species that incentivizes self-interested individuals to conform to social norms. In this talk, we will present the results of three functional magnetic resonance imaging (fMRI) studies showing that the medial prefrontal cortex and striatum play key roles in representing one’s own reputation and making decisions based on social reward (positive reputation). We will also present evidence that social reward based decision-making is selectively impaired in high functioning adults with autism.

Roberto Schonmann - A new approach to evolution in group structured populations.
2012-01-09 00:00
Roberto Schonmann: UCLA Department of Mathematics, Sao Paulo University Department of Applied MathThe evolution of cooperation and altruism are fundamental scientific challenges highlighted by their role in the major transitions in
life’s history, when natural selection acted simultaneously on several competing levels. The relevance of basic concepts, including group selection and Hamilton’s rule remain nevertheless controversial.
In this talk I will address these problems by introducing a new framework for modeling evolution in group structured populations, incorporating inter- and intra-group competition and migration. Combining group-centric with gene-centric perspectives in a constructive group/kin selection approach, we build methodology that allows for the analysis of arbitrary non-linear fitness functions, resulting from complex multi-individual interactions accross life cycles. This provides extensions of Hamilton’s rule and reveals conditions under which altruism can evolve when rare, but genetic relatedness in groups is modest. Emphasis on linear public goods games has supported the belief that inter-group selection favoring altruism
could only override intra-group selection favoring selfishness under exceptional conditions. In contrast, we show that for iterated public goods games, in which altruists cooperate or not in each round based on previous outcomes altruism can spread even when groups are large,
selection is weak and migration rates are substantially larger than the
inverse of group size. To obtain this result we show that in the absence of selection, when groups are large, the fraction of group members that are close relatives of a randomly chosen individual has a non-Gaussian distribution with a fat tail. As a consequence, even when altruistic alleles are rare in the population, they have a significant probability of concentrating in some groups, accruing substantial reproductive gains through synergy. (This is joint work with Renato Vicente and Nestor Caticha, from Sao Paulo University.)

Alison Gopnik - Childhood dependence and adult intelligence: Children as the Research and Development Division
2011-11-28 00:00
Alison Gopnik: UCBOne of the most striking generalizations in evolutionary psychology is the correlation between sophisticated and flexible learning-based knowledge in adult organisms and a long protected period of immaturity in the young. In terms of the classic altricial vs. precocial, or r vs. k distinction in evolutionary biology, the altricial species are more likely to rely on learned information as adults. Human beings, of course, have a particularly extended childhood, and are particularly marked by their reliance on learning. This fact suggests that there may be a kind of cognitive division of labor between children and adults. Children are, as it were, the research and development division of the human species, while adults are production and marketing. Children are designed to be particularly good at learning and exploration and adults are designed to exploit the information they have learned as children for purposes of planning. I will review a wide range of developmental and neuroscientific evidence that supports this hypothesis, including some very recent studies in our lab that empirically show that children may be better causal learners than adults. In particular, I will discuss this idea in light of recent work on the computational bases of cognitive development using ideas about probabilistic models and Bayesian learning.

Joel Sachs - Evolutionary origins and stability of bacterial symbioses
2011-11-21 00:00
Joel Sachs: UCRBeneficial bacteria improve our health and are crucial to crops plants and fodder animals. However, symbiosis is evolutionarily unstable: harmful mutants can invade symbiont populations and cause cooperation to collapse. My research encompasses both theoretical and empirical work on the evolution and maintenance of bacterial symbioses with eukaryotes. My theoretical work seeks to understand how symbiotic cooperation is maintained and to predict the conditions in which exploitative / pathogenic mutants invade. This theory has important applications for medicine (maintenance of gut, oral flora symbioses), agriculture (optimization of nitrogen fixing symbioses) and bio-production (e.g., selection of bacteria to perform biochemical reactions). My empirical interests are broad and I use a combination of experimental, molecular and genomic approaches. Currently, there are two overlapping research programs within my lab. One approach employs wet-lab techniques to study the evolution and breakdown of nitrogen-fixing plant symbioses (rhizobia). Our second and newer research program is mainly bioinformatic and investigates the origins and stability of bacterial symbioses writ large (e.g. across whole bacterial lineages) and thus over deep evolutionary time.

James Andreoni - Accidental Altruism: Economic Research on the Social Aspects of Giving.
2011-11-14 00:00
James Andreoni: UCSDGiving to those in need is inherently a social act. First, altruistic giving requires empathy for, or perhaps simply awareness of, those who are needy. Second, giving nearly always involves a social interaction between the donor and someone seeking a donation. Third, those who are generous tend to be admired by others, and people care both about admiring and being admired. This presentation will discuss recent research in both the lab and the field on audience effects, the power of asking, the coercive nature of empathy over simple awareness, and how ethnic and religious diversity influences charitable giving.

Simone Schnall - Emotions, Intuitions, and Morality
2011-11-09 00:00
Simone Schnall: CambridgeHow do people tell right from wrong? It used to be assumed that moral decisions are based on rational thought, such that people determine on objective facts and logical analysis what is morally acceptable behaviour. More recently, however, empirical findings suggest that decisions about morality and ethical behaviour are far from rational, but are often guided by emotional and other intuitions. I will discuss my research showing that first, embodied feelings and intuitions influence moral judgments, and second, positive moral emotions can be harnessed to bring about positive behavioural change. These findings suggest that emotions and intuitions play a powerful role in moral considerations

William Harbaugh - Competitive preferences across age and gender
2011-11-07 00:00
William Harbaugh: U of OregonOne potential explanation for some of the differences in incomes between men and women is a difference in preferences for economic competition. In experiments with real effort and cash payoffs men are more likely to select into winner-take-all tournaments, while women tend to choose individual piece-rate pay or equal payments based on group performance. This talk examines how these relative gender differences vary across age and over the menstrual cycle. With an eye towards possible policy interventions we also examine differences in the demand for feedback information, and differences in how the effect of feedback on past performance affects choices about competition.

Robin Nelson - Contextualizing Kinship: A Bio-cultural Study of Families and Health in Jamaica
2011-10-31 00:00
Robin Nelson: UCRIn this talk, I will explore the extent to which variability in the quality of familial and social relationships is correlated to the phenotypic expression of biological indicators of health status for adults and children. This research applies theories popularized in evolutionary ecology to a study of sociality and health in Manchester Parish, Jamaica. Using ethnographic methods, I identified culturally salient aspects of investment relationships amongst a lower class study population. Jamaica’s unstable economic climate necessitates increased investment from social and familial contacts and thus, provides the framework for studies of this received investment. Health outcomes were measured using anthropometric and immunological analyses. In this presentation, I will discuss my findings regarding the impact of a variety of investment relationships on health outcomes for (1) adults who are involved in romantic relationships and (2) adults who were children during the post-colonial era in Jamaica and (3) a recent study of children living in state-sponsored orphanages. These findings suggest that investment relationships in Jamaica, specifically with relatives, serve as one important factor in the maintenance of good individual health. These relationships are particularly important in the context of Jamaica’s risky and unstable economic environment.
