Center for Behavior, Evolution, and Culture

Brooke Scelza - Husband, Lover, Pater, Genitor: Paternity and concurrency in northwest Namibia
2019-10-07 00:00 (America/Los_Angeles)
Brooke Scelza: University of California, Los AngelesResearch on human mate preferences has been conducted mainly in industrialized societies, where multiple mating and concurrent partnerships are heavily stigmatized. However, cross-culturally, extra-pair partnerships are more common, and there is significant variation in the acceptance of such relationships, particularly for women. In order to better understand how a system of concurrency can be maintained, I will present data from 10 years of fieldwork with Himba pastoralists living in northwest Namibia, a culture where nonmarital partnerships are both common and normatively sanctioned. After presenting demographic data on the rates of concurrency and paternity in this population, I will discuss the potential benefits to women of having multiple partners, using both quantitative and qualitative data. Next, I will explore the reasons why men might tolerate, or even support, such a system, despite the paternity loss that accompanies non-marital sex. Finally, I will discuss how social norms about extra-marital sex, jealousy and paternal care support a system of concurrency in this population.

Kristi Lewton - Birth, bipedalism, and the evolution of the human hip
2019-09-30 00:00
Kristi Lewton: University of Southern CaliforniaLocomotion, gestation, and childbirth have had a significant impact on human culture and biology, including the morphology of the human hip. One of the most fundamental features of the human lineage is walking on two legs, and the emergence of this novel behavior had spectacular evolutionary consequences; the advent of material culture, extensive migrations and landscape use, and complex systems of trade were all contingent on obligate bipedality. Humans also have unusually large neonates, which has been thought to result in an ‘obstetrical dilemma’ in which there is an evolutionary tradeoff in females between having hips wide enough to accommodate the birth of a large infant, but also narrow enough to allow for efficient bipedal locomotion. This research uses integrative methods including biomechanical models, the comparative method, and morphological integration to examine tradeoffs, constraints, and adaptations of the human pelvis.

Kotrina Kajokaite - Testing hypotheses about social cognition with observational data: coalitions in white-faced capuchin monkeys
2019-06-03 00:00
Kotrina Kajokaite: University of California, Los AngelesCoalitionary recruitment offers a window into animal social cognition. However, naturally observed coalitionary conflicts are challenging to analyze because the researcher has no control over the context in which they occurred, and observed behavior patterns are typically consistent with multiple explanations. In this talk, I will present analyses of observational data of coalitionary solicitations during conflicts in wild capuchin monkeys, Cebus capucinus, collected at Lomas Barbudal Biological Reserve, Costa Rica. In this study we employed a statistical technique that models monkeys’ choices of allies during coalitionary conflicts while taking into account not only the attributes of the chosen individual, but also of the other individuals who were available to be solicited for help. This statistical technique also allows to simultaneously compare different hypotheses regarding which cues monkeys use and how these cues interact. Our analysis shows that capuchin monkeys use information about both relationship quality and dominance when recruiting allies during conflicts. Monkeys primarily use rank when recruiting an ally, but will also use relationship quality, particularly when the potential ally has low rank. This study provides evidence that nonhuman primates are able to classify other group members using multiple criteria simultaneously. In addition, this study presents a statistical technique that animal researchers can use to infer decision rules from observational data.

Courtney Meehan - The social worlds of infants, moms, and microbes
2019-05-20 00:00
Courtney Meehan: Washington State University Throughout our evolutionary history, and in much of the world today, human infancy has been characterized by a host of ancestral traits which include frequent maternal-infant contact, on-demand breastfeeding, co-sleeping, and cooperative breeding. These ancestral characteristics have, in part, supported the development of our altricial infants and enabled reproductive success in diverse environments, despite women’s narrow reproductive window and the costs associated with simultaneously rearing multiple dependent children. Here, I argue that these ancestral traits also serve as a critical pathway by which mothers and infants communicate, via microbiota, about their environment, priming the infant for the world in which he or she will be reared. Utilizing cross-cultural data on infant’s early environments and human milk composition, I characterize the diverse caregiving worlds of infants and explore how our early social environments and mothers’ life history characteristics are associated with the human milk microbiome (HMM). Human milk, once thought to be sterile, contains a diverse microbial community and as an early and consistent source of bacteria to infants, it is an important factor in the colonization of the infant gastrointestinal microbiome. Yet, the origins and role of the HMM are not yet fully understood. Our results identify multiple associations between maternal life history characteristics, our ancestral caregiving traits, and the HMM, providing initial evidence suggesting bi-directional maternal-infant communication during breastfeeding and that human milk composition may be socially-mediated.

James Liu - Collective Remembering across Generations and across Cultures: Evidence for National Narrative Templates, Developmental Variants, and Global Anchors
2019-05-17 00:00
James Liu: Massey University, New ZealandWhat is universal, what is characteristic of national political culture, and what is regionally influenced in the “living memory” of national history for people around the world? Selected data a reported from a massive multi-generational adult sample (N>27000) collected online in 2018-19, representative of 42 societies around the world). In responding to the question “Name 3 historic events that have occurred during the lifetime of people you know (or have known) that have had the greatest impact on your country”, historical foreshortening (i.e., nominating very recent events like the last election) was more common than generational differences. World War II was not nearly as dominant as in previous studies where events in world history were nominated, with 9/11 forming an alternative anchor for living memory in the United States. This passing away of WWII from living memory may weaken the soft power of the United States in other parts of the world. Points of difference between societies were far more salient than the few commonly shared global events, but there were some structural features shared in the collective remembering of developing societies around the world (e.g., from colonization to independence and reform). Prospects for convergence, divergence, and mutual friction are discussed, focusing on the Great Powers of China, Russia, the United States; as well as countries in the European Union, and Islamic societies.
A new measure of historical consciousness is proposed and used to examine the shape of national historical narratives, between individuals and across cultures. Degree of historical consciousness may be treated as an individual difference, consisting of both ability to recall collective events and openness to societal influences like mass media or the state. Different clusters of historical events informed different narratives of national identity within a given country, and these were systematically associated with important features of political psychology, like predispositions for prejudice versus for system justification, and the propensity to trust others and institutions in society. Living memory appears to be temporally malleable, as it is highly responsive to immediate crises facing society, but it is also anchored to foundational events spanning three generations.

Brian Wood - Hadza hunter-gatherer movement ecology and the sexual division of labor
2019-05-13 00:00
Brian Wood: University of California, Los AngelesHumans think about, explore, and use landscapes like no other species, reflecting our unique biological and cultural adaptations. One of these adaptations, observed in all hunter-gatherer societies, is a gendered division of foraging labor. The impacts that gendered economic roles have upon space use is a critical concern for evolutionary accounts of social organization and spatial cognition, but is not well understood. Behavioral ecology models propose that the rarity and mobility of targeted resources should predict movement patterns, and that strong gender differences in space use should emerge in a hunting and gathering context, owing to the different kinds of foods that men and women target. To test these ideas, I examine space use among the Hadza, recorded using GPS devices over 2,078 person-days of observation. In this talk, I will also present measures of spatial cognition, and examine correspondences between measures of cognition and spatial behavior.

Lee Gettler - The biology of fatherhood in context: Evolutionary origins, cross-cultural perspectives, and implications for men’s health
2019-05-06 00:00
Lee Gettler: University of Notre DameHuman males have a flexible psychobiological capacity to respond to committed parenting with shifts in hormones such as testosterone, prolactin, and oxytocin. These findings hint at evolved neuroendocrine capacities that help facilitate refocused priorities as men make the transition into fatherhood. Evolutionarily, these capacities likely emerged alongside humans’ “slow” life history. Today, fathers commonly cooperate with mothers to raise children. However, their involvement and roles are variable, as they likely were evolutionarily. Thus, the nature of fathers’ hormonal shifts and their influences on behavior are shaped by the ecologies, cultural contexts, and family systems in which those fathering roles find expression. Evolutionary approaches to the biology of fatherhood often focus on the role of hormones, such as testosterone (T), as mechanisms mediating trade offs between competing mating and parenting demands. Meanwhile, clinical research in industrialized contexts has shown the mental and physical risks that can accompany “low T.” Men in contexts such as the US also experience post-partum depression and commonly have their physical health decline after becoming fathers (e.g. “dad bod”). Few efforts have been made to connect the dots between these sets of findings. Bringing together these perspectives using data from my research in the Philippines, Congo-Brazzaville, and the US, I will explore how men’s hormonal physiology variably responds to parenthood and relates to men’s family behaviors. I will then present recent work on how variation in paternal T relates to men’s risks for depression and chronic disease and will explore these perspectives through the lens of evolutionary medicine, particularly the idea that the biology of fatherhood may be mismatched to the expression of parenthood for men in some contemporary societies.

Katie Starkweather - “Why Risk It? Health Outcomes of Shodagor Women’s Work”
2019-04-29 00:00
Katie Starkweather: University of New MexicoGendered divisions of labor are an essential aspect of human life. The two primary components of the gendered division of labor – subsistence work and childcare – are critical for child survival, health, and well-being, as well as the reproductive success of parents. In most human societies, women and men display similar, gendered patterns of behavior in meeting the subsistence and childcare needs of the household. Human behavioral ecologists have developed theory to explain those trends, but still have very little understanding of deviation from them, particularly regarding women’s work. Among Shodagor people in Bangladesh, a semi-nomadic, boat-dwelling community, women’s work varies in the extent to which it adheres to cross-cultural norms of compatibility with childcare and risk aversion. This talk will highlight some of my recent work on the health outcomes and reproductive decision-making that are associated with women’s work when it is incompatible with childcare and produces high levels of economic risk. Preliminary evidence suggests that women who engage in these cross-culturally unusual behaviors are making tradeoffs related to child health and nutrition and are strategically making reproductive decisions that may allow them to maximize time spent working. I will discuss upcoming plans for a project that is based on based on these findings and involves a more detailed assessment of adult and child health outcomes as they relate to women’s work and childcare.

Hazel Byrne - Molecular Neotropical Primatology: Titi Monkey Evolution
2019-04-22 00:00
Hazel Byrne: University of California, Los AngelesNeotropical primates are a diverse clade of primates that inhabit South and Central
America. Broadly speaking, in comparison to “Old World” primates originating in Africa and Asia, most Neotropical primates are strikingly understudied with many outstanding questions regarding their evolution. Among the least studied and appreciated groups are the monogamous pair-bonding titi monkeys (subfamily Callicebinae), yet titis are also among the most species rich primate radiations with over 30 species recognised. Prior to 2016, the only phylogeny focusing on titi monkeys was derived from morphological characters in the 1990’s, and owing to their morphological conservatism, the depth of diversity found in this clade was highly underestimated. The long-term assumption that titis represented a group of extremely similar primates impacted how we have studied them (i.e., existing research is based on a few “representative” species). This talk explores the insight gained into the evolutionary history of these enigmatic primates through molecular phylogenetic studies within the past three years. These studies have revealed deeply divergent titi lineages dating to the Miocene, uncovered a complex evolutionary history, and highlighted the consequences of previous assumptions for our already limited understanding of callicebine biology.

Pam Yeh - How interactions among multiple stressors affect the ecological and evolutionary trajectories of populations
2019-04-15 00:00
Pam Yeh: University of California, Los AngelesAll natural populations deal with multiple stressors. Yet there is limited understanding of how populations are impacted by higher-order interactions — more than two stressors. In this talk I will explain my new conceptual and experimental work to examine higher-order interactions among antibiotics in bacterial populations. I will also present recent work from my group that shows bacteria likely co-opted ancient stress response mechanisms to extreme temperatures in order to deal with more recent antibiotic stresses. This co-opting avoids the need for de novo evolution of response mechanisms to antibiotics.

Alexandra Binder - Epigenetics and the Developmental Origins of Health and Disease
2019-04-08 00:00
Alexandra Binder: University of California, Los AngelesThere is extensive epidemiologic and experimental evidence linking early life conditions to adult health. Epigenetic modifications are suspected to play a role in mediating these associations by providing a cellular memory of gene regulation shaped by exposures during critical windows of development. In this lecture, I will discuss some of my research into the relationships between epigenetic patterns and early life predictors of adult disease susceptibility. I will highlight our recent investigations into specific patterns of DNA methylation that influence pubertal development among a longitudinal cohort of girls in Santiago, Chile. More generally, I will detail salient methodological considerations for identifying determinants of epigenetic variation in observational human studies. I will also outline generalizability and reproducibility concerns within the field of epigenetic epidemiology, and how these considerations should inform study design and the discussion of study implications.

Ashley Hazel - Ecological dynamics of sexually transmitted infections among Namibian pastoralists
2019-04-01 00:00
Ashley Hazel: Stanford UniversityPopulations that are dependent upon physical environments for their immediate livelihoods utilize subsistence strategies that are both well adapted to predictable environmental variability (e.g., seasonality) and resilient to unpredictable shocks (e.g., drought). Livelihood strategies that entail high degrees of mobility typically have temporal and spatial heterogeneities in social contact, which influences infection dynamics for pathogens that require prolonged or repeated contact for transmission, such as sexually transmitted infections (STIs) or tuberculosis.
In this talk, I present my work on the epidemiology of two STIs—HSV2 and gonorrhea—among a group of semi-nomadic pastoralists in Kaokoveld Namibia, where sexual-partner concurrency functions not just as an STI risk factor but, crucially, as an ecological strategy. I find that extreme geographical remoteness is associated with a higher HSV2 (viral) transmission rate. In contrast, ephemeral population density and social aggregation are associated with higher gonorrhea (bacterial) prevalence. Furthermore, both predictable and unpredictable climate variation influenced sexual-networks, which has important implications for the impending effects of climate change.

Raziel Davison - Evolutionary Retrospectives on the Human Life History Trajectory
2019-03-11 00:00
Raziel Davison: University of California, Santa Barbara We investigate human life history evolution by comparing smallscale subsistence societies and chimpanzees to identify the roles that fertility and mortality play in driving population-level fitness differences. We discuss differences in the selection pressures facing individuals of different ages and to make inferences about the trajectory of human life history evolution. Most human populations are growing but post-reproductive survival decouples population growth from lifespan, with high fertility driving rapid growth in some societies and low fertility balancing longevity to maintain near-stationarity in others. Chimpanzee declines are decoupled from fertility because mortality attrition limits higher potential fertility contributions. Selection pressures suggest that variable child survival likely regulated human population dynamics over evolutionary history and may reflect bet-hedging costs of high fertility, with quality/quantity trade-offs constraining the evolution of slower life histories. Common stationarity conditions may represent invariant allometry of chimpanzee and human life histories. Among humans, production and knowledge transfers constituting fitness contributions of post-reproductive adults part the veil of selection to favor long post-reproductive lifespans, but in chimpanzees transfers
are limited and reproductive senescence tracks mortality closely.

Dan Hruschka - What does it mean to replicate studies in a cultural species?
2019-03-04 00:00
Dan Hruschka: Arizona State University Replicating a study among our fellow humans requires a researcher to interact with study participants according to protocols that are comparable with previous studies. However, thanks to humanity’s rich capacity for cultural learning, it can be challenging to identify what counts as a “comparable protocol” across different human groups. Specifically, diverse culturally learned capacities, motivations, symbolic connections, and expectations for appropriate social interactions can make some protocols impossible to implement directly across cultures while rendering the results of other “workable” protocols nearly impossible to interpret. I used examples from our work studying the social determinants of giving to illustrate: (1) the extent of this problem, and (2) how overcoming such challenges can tell us about our tacit models of how humans should think and behave. In this way, such efforts at translation are not just a methodological exercise, but can also inform our models of human psychological and behavioral diversity.

Josh Snodgrass - Life history tradeoffs between childhood growth and immune function among Shuar forager-horticulturalists of Amazonian Ecuador
2019-02-25 00:00
Josh Snodgrass: University of OregonImmune function is an energetically costly physiological activity that can divert calories and other resources away from less immediately essential life history functions such as growth. However, direct evidence for immune-related tradeoffs among humans remains sparse. In this talk, I discuss longitudinal research among Shuar children (4-11 years old) that uses high-resolution linear growth data and dried blood spot samples for four immune measures. This research documents consistent negative effects of immune function on growth, with children experiencing up to 49% growth reduction during periods of mildly elevated immune activity. Additional findings show that tradeoffs are immunologically and temporally diverse, and also document a particularly detrimental impact of acute inflammation on growth though these inflammation-related tradeoffs with growth are buffered by body fat. I conclude by discussing the role of immune-related tradeoffs in driving patterns of human growth faltering, developmental metabolic plasticity, and life history evolution.

Melanie Martin - Human infant feeding: evolved strategies, individual optimums, and public health
2019-02-11 00:00
Melanie Martin: University of WashingtonAcross past and present human populations, breastfeeding and weaning practices have been demonstrably varied. Though this variation is largely influenced by ecological and socioeconomic factors, comparative primate and human biological and cross-cultural evidence further suggests that flexible mixed-feeding is an evolved human strategy. In this talk, I review the differences in infant energetic needs and maternal time, physical, and reproductive constraints that favor individual optimums for exclusive and total breastfeeding durations. I draw
on my work with indigenous Tsimane and Qom/Toba families to illustrate that (1) early (“suboptimal”) mixed-feeding can still be compatible with long-term, intensive breastfeeding and (2) that more discreet measures of feeding trajectories and their multidirectional effects on growth and other biological processes should be considered in assessing relationships to health outcomes. In closing I emphasize that these positions are not incompatible with current age-delineated feeding recommendations, which are essential for uniform public health messaging
and related policy development. Instead, an evolutionary and biocultural perspective may inform parallel dialogs among families and health care providers that acknowledge diverse needs and circumstances in shaping individual feeding optimums.

Courtney Meehan - [CANCELED] The social worlds of infants, moms, and microbes
2019-02-04 00:00

Nandita Garud - The Bacteria Evolving Within Us
2019-01-28 00:00
Nandita Garud: University of California, Los AngelesThe human gut microbiome is comprised of a complex ecosystem of microbes that reside inside of us and play an important role in our health. With as many as a billion new mutations entering our microbiomes per day, bacterial genomes inside us have a great opportunity to evolve rapidly, unlike our own genomes, which change very little throughout our lifetimes. For us humans, this genetic dynamism is both an opportunity (e.g., enabling digestion of new foods) and a challenge (e.g. the evolution of drug resistance). Despite the potential importance of these effects, we currently know very little about if and how bacteria living in us evolve. I will present our recent work quantifying the evolutionary dynamics of ~40 prevalent species of gut bacteria. We find that gut bacteria can evolve within humans on short timescales (~6 months), but over our lifetimes resident bacteria are typically replaced by distantly related strains. These results suggest that gut bacteria can evolve on human-relevant timescales, but that there are limits to the extent of local adaptation.

Angela Garcia - The Embodiment of Stress: Do diurnal cortisol-immune interactions and parasitic infection moderate social influences on health among immigrant women on Utila?
2019-01-14 00:00
Angela Garcia: Arizona State University Cardiometabolic diseases (e.g. heart disease and diabetes) are the leading cause of death and morbidity worldwide. Diabetes, for example, will double in the next 30 years, with 80% of the rise occurring in middle and lower- income countries. Social, economic, and ecological landscapes often change alongside market integration and development, making it difficult to tease apart the primary agents responsible for these changes in epidemiological profiles. Further, at the population-level, there remains drastic individual variation in disease risk. Why are some individuals in a population at greater risk of poor health than others? What can an evolutionary approach offer in helping us to understand causes (and potential treatments) for current health disparities? This research seeks to address these questions by targeting three important but under-studied factors that contribute to disease risk: discrimination, psychosocial stress, and ecological variation. In this talk, I couple fieldwork and ethnography with theory from evolutionary biology (e.g. life history theory and phenotypic plasticity), biocultural anthropology (e.g. perceptions of self and the environment), and chronobiology (e.g. diurnal regulation of hormones and immune function), to examine links between social and ecological parameters of the environment, hormonal measures of stress, immune function, and risk for diabetes among Honduran immigrant women on the island of Utila.

Dan Blumstein - The Sound of Fear
2019-01-07 00:00
Dan Blumstein: University of California, Los AngelesWhat makes certain sounds scary? I will describe insights gained from over three decades of studying alarm calls and fear screams in marmots (which are large, mostly-alpine, ground squirrels) throughout the northern hemisphere. Fear screams are remarkably similar across taxa and they seem to be particularly evocative to many species. My studies of non-humans suggest that it is the noise and non-linearities in them that is what evokes negative emotions and heightened responses in those hearing them. I formalize this in ‘the non-linearity and fear hypothesis’ and discuss my tests of the hypothesis in studies of marmots, birds, film soundtracks, and humans. The sound of fear is non-linear.

Amy Parish - Reflections on Our Closest Living Relatives and Ourselves: Lessons from the Bonobo Sisterhood
2018-12-03 00:00
Amy Parish: University of Southern California“Oooooh, I want to be like youuuu, …walk like you, talk like you, tooooo.” So goes the lament of Louie, the Orangutan King in “The Jungle Book”. He wishes he could be like a human. In contrast, Mogli, the human boy in the movie, thinks of himself as just one of many types of forest animal. The movie represents a conflict in humanity’s search for self-identity. What really separates “man” from “animal”, if indeed there is such a separation? We are desperate to know. Approximately 200 species including humans belong to the Primate mammalian order. Like all animals, they are faced with the problems of how to survive, breed and rear offspring. The mating behavior of the apes is particularly complex and fascinating. Chimpanzee (Pan troglodytes) societies are typically characterized as physically aggressive, male-bonded and male-dominated. Their close relatives, the bonobos (Pan paniscus), differ in fascinating and significant ways. For instance, female bonobos bond with one another, form coalitions, and dominate males. Both species are equally “man’s” closest relative. How do these findings change our views of our evolution and ourselves? This talk explores the sexual and social behavior of one of our closest living relatives: the bonobo.

Thomas J. H. Morgan - Experimental Human Gene-culture Coevolution
2018-11-26 00:00
Thomas J. H. Morgan: Arizona State UniversityThe evolution of human behavior and cognition is often studied with a combination of theory and experiment—theory is used to explore evolutionary dynamics, and generate predictions that are tested empirically. However, agent psychology is typically highly simplified and so it can remain unclear whether human behavior would produce the same evolutionary dynamics. To address this question, I describe a new method, “experimental evolutionary simulations”, that combines aspects of theoretical and empirical approaches by inserting large numbers of human participants into an evolutionary simulation. I use this approach to provide new data concerning the ability of human social learning to adapt to an unstable environment. Theory has identified different social learning strategies that are highly successful or unsuccessful in a changing environment. Experimental evidence suggests that human behavior is broadly consistent with many of these predictions and so it remains unclear how well a population of human learners would cope with environmental change. Across a series of experimental evolutionary simulations, I find that although human behavior is broadly consistent with theoretical strategies that are successful in a changing environment, this similarity is insufficient to actually buffer human populations against environmental change. I conclude that human psychology is designed for high fidelity copying and not adapting to environmental novelties. More generally I suggest that experimental evolutionary simulations are a valuable complement to existing methods in the evolutionary study of mind and behavior.

Jeremy Koster - Cross-Cultural Variation in the Life History of Human Foraging Skill
2018-11-19 00:00
Jeremy Koster: University of Cincinnati, OhioHumans are distinguished from other hominoids by several life history traits, including prolonged childhoods, relatively brief inter-birth intervals, and extend post-reproductive lifespans. To explain the evolution of these traits, anthropologists have hypothesized that the cognitive demands of hunting necessitate extensive learning, which promotes late maturation and inter-generational food sharing. In this analysis, my colleagues and I evaluate a key component of this conceptual model, namely that advanced hunting skill is particularly evident among middle-aged hunters. We compile data on subsistence hunting from 40 sites around the world in a sample that includes over 23,000 hunting records from approximately 1,800 individual hunters. We use multilevel modeling and a life history model to estimate the latent skill of hunters as a function of their age. On average, hunters reach their peak at approximately 31 years old. The peak is not pronounced, however, and there is cross-cultural variation in age-related skill that challenges earlier findings. These results accentuate the need for additional longitudinal data on foraging activities as a counterpoint to theoretical models of life history evolution.

Susan Schaffnit - ‘Child marriage’ in context: understanding the drivers of early marriage in rural Tanzania
2018-11-05 00:00
Susan Schaffnit: University of California, Santa BarbaraA global campaign to end ‘child marriage’ (i.e. marriage before 18 years) has emerged over the last decade as part of growing international commitments to address gender inequities and improve female wellbeing. Proponents of this movement assert that young brides have negligible autonomy in the marriage process and that marrying under 18 years has resolutely negative impacts on wellbeing. This concern surrounding early marriage has largely proceeded without theoretical engagement with anthropologists and despite gaps in supporting evidence of harm to women. Using data collected in rural, northwest Tanzania where early marriage is common, I will (1) discuss local views on marriage, (2) test hypotheses as to why early marriage is common despite purported harm. Our findings suggest that early marriages can be understood as serving the strategic interests of both parents and daughters in some circumstances. I will discuss the generalizability of this finding and implications for the ‘end child marriage’ movement.

Daniel Benyshek - Human Maternal Placentophagy: evolutionary roots, cross-cultural occurrence, and an emerging post-industrial health trend
2018-10-29 00:00
Daniel Benyshek: University of Nevada Las VegasMaternal placentophagy, the mother’s consumption of the ‘afterbirth’ following parturition, is a ubiquitous behavior among terrestrial mammals – including non-human primates. Despite myriad hypothesized fitness-enhancing consequences of the behavior, including predator avoidance, improved lactation, enhanced care-taking behaviors, maternal analgesic effects, and the replenishment of maternal nutrients, among others, human maternal placentophagy is unknown in the cross-cultural ethnographic literature. The conspicuous absence of placentophagy in humans as a traditional cultural practice, raises interesting questions relative to its evolution in other mammals, the reasons for its apparent absence among historic and contemporary human populations, and its implications for maternal and child health in the context of an emerging placentophagy ‘alternative health’ practice among some women in post-industrial societies.

Eduardo Guerra Amorim - Migration and social organization in medieval Europe: a paleogenomic approach
2018-10-22 00:00
Eduardo Guerra Amorim: University of California, Los AngelesDespite centuries of research, much about the barbarian migrations that took place between the fourth and sixth centuries in Europe remains hotly debated. To better understand this key era that marks the dawn of modern European societies, we obtained ancient genomic DNA from 63 samples from two cemeteries (from Hungary and Northern Italy) that have been previously associated with the Longobards, a barbarian people that ruled large parts of Italy for over 200 years after invading from Pannonia in 568 CE. Our dense cemetery-based sampling revealed that each cemetery was primarily organized around one large pedigree, suggesting that biological relationships played an important role in these early medieval societies. Moreover, we identified genetic structure in each cemetery involving at least two groups with different ancestry that were very distinct in terms of their funerary customs. Finally, our data are consistent with the proposed long-distance migration from Pannonia to Northern Italy.

Sarah Benson-Amram - Individual, Social, and Ecological Influences on Problem-Solving Abilities
2018-10-15 00:00
Sarah Benson-Amram: University of WyomingAs urban centers all over the world have grown, biologists have struggled to explain why some species can invade and thrive despite human-induced environmental change whereas others suffer often to the point of extinction. One potential explanation is that the evolution of advanced cognitive abilities has enabled some species to exhibit more flexible behavioral responses to anthropogenic disturbances. Empirical evidence for this hypothesis is lacking, however, as it is difficult both to assess cognition in wild animals and to standardize assessments of cognition across multiple species in differing environments. The main goals of my research program are: 1) to understand the selection pressures driving the evolution of intelligence, 2) to clarify how the expression of behavioral flexibility and other cognitive abilities changes depending on the individual’s personality, the presence and identity of conspecifics, and the ecological environment, and 3) to investigate how cognition might facilitate successful adaptation to human-altered environments. In this talk, I will touch upon all three of these areas of research. I will first discuss my work examining the evolution of brain size and problem-solving abilities in a large comparative study of zoo-housed carnivores. I will then describe results from our research examining cognitive abilities in wild and captive populations of two highly successful carnivores, the spotted hyena and the raccoon. Finally, I will briefly describe some current research in our lab examining the interaction between personality and problem-solving performance in the monogamous zebra finch.

Michael Rescorla - Foundations of Cognitive Science: Mental Representation
2018-10-08 00:00
Michael Rescorla: University of California, Los AngelesJust as the heart serves to pump blood and the stomach serves to digest food, one of the mind’s principal functions is to represent the world. For instance, I have various beliefs about Barack Obama: that he was once president of the United States, that he is married to Michelle Obama, and so on. These beliefs represent Barack Obama as being a certain way. Thus, the mind somehow reaches beyond itself to external reality, depicting the world as having certain features. In that sense, the mind is a representational organ. Traditionally, philosophers have emphasized the mind’s representational capacity as among its most important properties. Cognitive science builds upon this tradition, assigning a foundational role to mental representation when constructing theories of perception, motor control, navigation, reasoning, decision-making, planning, linguistic communication, and other core mental activities. Cognitive scientists elaborate the traditional picture of the mind as a representational organ into rigorous, empirically well-confirmed theories.

Elizabeth Chrastil - Spatial Knowledge, the Environment, and Individual Differences in Navigation Ability
2018-10-01 00:00
Elizabeth Chrastil: University of California, Santa BarbaraOrienting oneself in novel environments, as well as finding and remembering the locations of resources, is critical for human and animal existence. Despite the importance of this skill, getting around is easy for some people, while others struggle. Working at the interface between immersive virtual reality and neuroimaging techniques, my research demonstrates how these complementary approaches can inform questions about how we acquire and use spatial knowledge. In this talk, I will share emerging research about the relationship between humans and the environment during navigation, centering on three main themes: 1) how we learn new environments, 2) the type of spatial information we learn from environments, and 3) how individuals differ in their spatial abilities, including sex differences. This talk will integrate these behavioral and neuroimaging studies with an understanding of how the environment shapes our navigational abilities to inform new frameworks of spatial knowledge.

Jim Sidanius - Social Dominance Theory and the Dynamics of Gendered Prejudice
2018-06-04 00:00
Jim Sidanius: Harvard UniversityUsing Social Dominance and evolutionary theory as theoretical frameworks, we argue for a model entitled the Theory of Gendered Prejudice (TGP), which in broad terms, suggests that arbitrary-set discrimination must be understood as an inherently gendered phenomenon. Employing multiple methodologies, I argue that: 1) In general, males will display higher levels of xenophobia, discrimination, social predation, and social dominance orientation than will females, everything else being equal. 2) Males will tend to be both the primary perpetrators, and the primary victims of arbitrary-set discrimination. 3) The motives for outgroup discrimination are somewhat different for males and females.
