Center for Behavior, Evolution, and Culture

Anne Warlaumont - Modeling the Evolution and Development of Human Vocalization
2016-05-09 00:00 (America/Los_Angeles)
Anne Warlaumont: University of California, MercedHumans use a wide variety of types of vocal signals to communicate with other humans. Some of these sounds, such as crying, shrieking, and laughing, are thought to be closely related to those of our primate relatives. Others, especially babbling, speaking, and singing, appear to rely to a great extent on learning during infancy and early childhood. I will present a set of computational models that attempt to provide an account for how selection pressures and physiological mechanisms combined to create the adult human vocal repertoire.

Athena Vouloumanos - How Early Perceptual Biases Shape Human Communicative Development
2016-05-02 00:00
Athena Vouloumanos: New York UniversityLike many animals, human infants have biases for the vocalizations of their own species, preferring speech to many non-speech sounds just hours after birth. How do these early proclivities develop and how do they contribute to human communicative development? In her talk, Athena Vouloumanos will draw from behavioral and neural data to discuss how early human perceptual biases are quickly refined and how infants come to recognize that speech is a means for communication, allowing one person to transfer information to others. Before preverbal infants produce or understand many words, they recognize how speech is used by others to communicate about different types of entities in the world. This early communicative competence may provide infants with a channel for learning from others and lay a foundation for our social and cultural life as humans.

Jerry Siegel - Natural Sleep and Its Seasonal Variations in Three Pre-Industrial Societies
2016-04-25 00:00
Jerry Siegel: UCLAHow did humans sleep before the modern era? Because the tools to measure sleep under natural conditions were developed long after the invention of the electric devices suspected of delaying and reducing sleep, we investigated sleep in three preindustrial societies[1-3]. We find that all three show similar sleep organization, suggesting that they express core human sleep patterns, likely characteristic of pre-modern era Homo sapiens. Sleep periods, the times from onset to offset, averaged 6.9-8.5-h, with sleep durations of 5.7-7.1-h, amounts near the low end of those industrial societies[4-7]. There was a difference of nearly 1-h between summer and winter sleep. Daily variation in sleep duration was strongly linked to time of onset, rather than offset. None of these groups began sleep near sunset, onset occurring, on average, 3.3-h after sunset. Awakening was usually before sunrise. The sleep period consistently occurred during the nighttime period of falling environmental temperature, was not interrupted by extended periods of waking and terminated, with vasoconstriction, near the nadir of daily ambient temperature. The daily cycle of temperature change, largely eliminated from modern sleep environments, may be a potent natural regulator of sleep. Light exposure, was maximal in the morning greatly decreasing at noon, indicating that all three groups seek shade at midday and that light activation of the suprachiasmatic nucleus is maximal in the morning. Napping occurred on <7% of days in winter and <22% of days in summer. Mimicking aspects of the natural environment might be effective in treating certain modern sleep disorders.

Ed Vul - Do People Make Decisions Via a Bag of Error-Prone Tricks?
2016-04-18 00:00
Ed Vul: UC San DiegoHuman behavior is robust, adaptable, and, human behavior often deviates from the utility maximizing “rational” agent. This is usually attributed to people relying on an assortment of cheap heuristics to make efficient, but frequently biased, decisions. While the heuristics and biases research program has highlighted the many deviations of human behavior from that of simplistic economical agents, it has also yielded a morass of idiosyncratic, unreliable, and often contradictory biases, with no method to decide which heuristics will play a role in a given situation. Here I will describe our recent progress on an alternate approach: accounting for the successes and foibles of human behavior by assuming that people are more sophisticated, robust, and probabilistic than simple economic agents, but must carry out these sophisticated inferences under cognitive resource constraints. This approach yields a single framework for human decision-making: resource-rational probabilistic inference. This parsimonious, predictive account reconciles economic and psychological models of decision making and behavior.

Rose Scott - Can Babies Read Minds? False-Belief Reasoning in Early Childhood
2016-04-11 00:00
Rose Scott: UC MercedA large part of our daily lives involves interpreting other people’s behavior in terms of their underlying mental states. In particular, the capacity to recognize that others may hold and act on false beliefs plays a vital role in social interactions. The question of when and how false-belief understanding develops is currently the subject of considerable debate. In this talk, I will present recent evidence suggesting that a robust understanding of belief is present in infancy, but children’s ability to demonstrate this understanding depends on situational demands. I will also discuss ongoing projects that explore how cultural factors might give rise to individual variation in the use of this ability.

Robbie Wilson - Costs and Benefits of Dishonest Communication: Parallels Between Cheating Crustaceans and Diving Soccer Players
2016-04-04 00:00
Robbie Wilson: University of QueenslandAnimals routinely compete for access to limited resources, including food, territories or mates. Because combat is energetically costly and increases the risk of injury or death, individuals should avoid fighting unless they have a reasonable chance of winning. Specialised structures such as teeth, claws or horns can be used to show off potential strength, so that opponents can assess each other without contact and decide whether or not to escalate. In most cases, animals should only fight when the competitors are closely matched, possess similar perceived strengths, and when the resources are valued highly. But what happens if the signal is difficult to interpret, or is an unreliable indicator of strength? Crustaceans use their claws in fighting, but since the claw muscles are hidden within an exoskeleton, competitors cannot determine each other’s true strength without contact. This situation allows some individuals to deceive others and gain more resources by growing large claws that appear strong but are actually weak. In this talk, I examine the costs and benefits of dishonest communication in crustaceans to understand how such strategies evolve in nature. In addition, I use a similar approach to explore the expression of one of the most maligned behaviours in world sport – when soccer players pretend to be kicked by opponents and ‘dive’ to the ground to fool referees. Using these very different but parallel study systems, I will discuss how signals are kept mostly honest in nature and how this impacts human communication when aggression may be based on unreliable information.

Chris Kuzawa - Brain Energetics and The Evolution of Human Childhood
2016-03-28 00:00
Chris Kuzawa: Northwestern UniversityHumans are unusual in having a childhood stage characterized by a prolonged period of exceptionally slow growth. Many hypotheses have been proposed to explain why humans have evolved this life history stage. In this talk, Chris Kuzawa will discuss his recent collaborative work that quantifies the costs of human brain development and uses this information to shed light on the evolution of human life history. Compiling data from brain imaging studies, they find that the costs of the brain do not peak at birth, when relative brain size is largest, but at 4-5 years of age, when the brain consumes the equivalent of 66% of the body’s energy use at rest. This childhood peak in brain costs reflects the proliferation of energy-intensive synapses prior to experience-driven synaptic pruning. Consistent with the hypothesis of a brain-body growth trade-off, body weight growth rate follows an inverse, linear relationship with brain glucose demands from infancy until puberty, and maximal brain glucose demands co-occur developmentally with the age of slowest body weight gain. These findings provide rare empirical evidence that humans evolved very slow body growth to free up energy for our unusually costly brain development. In addition, the finding that the peak in brain energy needs occurs after the age of weaning in most traditional small-scale societies shows that much of the energetic costs of human brain development are not provided by maternal metabolism, but by social provisioning and allocare.

Jeff Winking - State of the Union: The Fate of the Paternal Investment Model of Human Marriage
2016-03-07 00:00
Jeff Winking: Texas A&MFathering traditionally played a central role in the evolutionary stories of human marriage. Paternal investment proved a convincing lynchpin linking together numerous hallmark aspects of the human adaptive strategy: the capacity for long-term romantic bonds, altricial infancy, extended juvenile dependence, etc. However, recent theoretical work suggests that the importance of paternal investment is an unlikely candidate for the primary selective force behind the evolution of long-term pairing in humans; indeed, paternal care likely evolved within the context of pre-existing pair-bonds. Here I explore the numerous scenarios that have been put forth to explain the “marriage-first” phylogenetic order and the role that paternal investment still plays in reconstructing the evolution of human pair-bonding.

Mirta Galesic - Early Development of Human Cooperation: The Role of Interdependence
2016-02-29 00:00
Mirta Galesic: Santa Fe InstituteThe importance and scale of cooperation in human societies is unmatched among other primates and is considered to be a major contributor to our species’ exceptional success. Given that cooperation seems so useful, it is surprising that it flourished only in humans but not in other primates who had similar cognitive abilities as our ancestors or lived in similar circumstances. Large-scale human cooperation is successfully explained by models of cultural group selection, but these models require a relatively advanced social cognition already in place. To explain early origins of human social cognition and cooperation, cooperative breeding and cooperative foraging accounts have been proposed. However, computational models of these accounts that would enable more precise understanding of the underlying mechanisms are still scarce.
We develop a computational model of one possible mechanism underlying the early development of human cooperation, based on interdependence. We show that the interdependence might have increased because several otherwise non-remarkable and ubiquitous factors came together for our early ancestors: specific physical properties of Early Pleistocene environments, characteristics of our early ancestors’ social structure, and their cognitive abilities. Together, these factors might have led to increased value of group foraging, which in turn led to increased interdependence, and eventually to higher propensity to share food with non-kin. This propensity could have been instrumental for the development of further prosocial tendencies, ultimately paving the way for the development of large-scale cooperation through cultural group selection, emerging in Middle and Late Pleistocene.

Paul Smaldino - Learning About Social Evolution with Extremely Unrealistic Models
2016-02-22 00:00
Paul Smaldino: UC DavisThe lives of social animals, none more so than humans, are shaped by cooperative interactions. Sharing, exchange, and synergy are the name of the game. Understanding the origins of cooperative behavior with any clarity often requires formalization of theories in the way of mathematical and computational models. These models by necessity ignore many details of an organism’s ecology, life history, and behavioral repertoire. Nevertheless, models provide crucial scaffolds for theory development, partly by explicitly declaring all of their assumptions and thereby making their limitations clear. That said, we can always stand to improve. I will discuss mathematical and computational models of the evolution of cooperative behavior, and how our assumptions about individual behavior, life history, and environmental structure influence our conclusions concerning how social populations evolve. In particular, I will focus on the advantages of complicated models in which life history and population structure are included, even when those factors are not the explicit targets of investigation.

Sean Prall - Immunity, Stress, and Development: The Role of Adrenal Androgens in Human Evolutionary Biology
2016-02-08 00:00
Sean Prall: University of Washington School of MedicineThe developmental pattern of adrenal androgen production is unique to humans and chimpanzees, and this pattern is thought to have important implications in human evolutionary biology. Unlike other hormones, the ultimate role of adrenal androgens is not well understood despite the important physiological roles these hormones play. The adrenal androgen DHEA in particular has been implicated in shaping cognitive evolution, acting in an adaptive fashion to buffer the effects of stress, and as an important agent in bolstering immunocompetence. Recent research in the pattern of development in orangutans suggests adrenal androgen production is shared across higher apes, and is not likely related to primate social conditions. In humans, DHEA is found to play potent and diverse roles in different aspects of immune function, suggesting an important role for human ecoimmunology. Additionally, DHEA is related to acute and chronic stress activation, and may play an adaptive role in shaping acute stress responses. These results shed light on an evolutionary and physiologically relevant hormone, and implicates DHEA as an important mediator of human life history strategies.

Stephanie White - Cycling in the Brain: Molecular Insights Into Vocal Learning
2016-02-01 00:00
Stephanie White: UCLAHumans and songbirds learn their vocalizations through social interactions and sensorimotor experience. These processes enlist implicit learning, a critical component of social cognition. Deficits in implicit learning including language disorders have devastating consequences for social integration and well-being. To treat or prevent these deficits, the neural mechanisms for learned vocal communication must be understood. Songbirds are one of the few animal models in which one can study the language subcomponent comprised by socially-learned vocal communication because, like humans but unlike rodents or non-human primates, they learn a significant portion of their vocalizations. They do so in a manner that exhibits key parallels to speech development and maintenance. Parallels include reliance on critical periods, cortico-basal ganglia circuitry, ongoing auditory inputs, hormonal factors and genes such as the forkhead transcription factor known as FoxP2. Using behavioral paradigms, we found that songbirds actively regulate their own levels of FoxP2 within area X, the basal ganglia sub-region dedicated to vocal learning. We paired this ethological approach with modern systems analytic techniques and found that singing activates distinct ensembles of gene expression in area X that are not similarly co-activated in adjacent tissue comprised of similar cell types. Thus, ‘molecular microcircuitry’ exists alongside anatomic and synaptic microcircuitry that, together, functionally specify the brain, in this case, for vocal learning. Behavior-linked regulation of this molecular microcircuitry appears critical for vocal learning.

Marcus Hamilton - Biological Scaling and the Evolution of Human Ecology
2016-01-25 00:00
Marcus Hamilton: Santa Fe InstituteWe can observe, examine and study the world around us meaningfully at many scales. Biologists may study genes, populations, species, ecosystems, or the biosphere. Social scientists may study the behavior of individuals, the dynamics of cities, or aspects of the archaeological past. But of course, at a coarse-grained level we are all examining the same system, just at different scales, and so the question then becomes; how do we integrate across all these scales to understand something about the fundamental mechanisms driving the complexity of living systems, including humans? In this talk I will introduce the scaling approach to understand the structure and function of biological systems, and how we can leverage insights gained in the biological realm to understand how human ecology has evolved. I will argue that economies of scale are fundamental to life, including human societies, and the scaling approach provides a powerful mathematical and statistical framework for understanding why.

Bruce Ellis - Childhood Experience, Development of Reproductive Strategies, and Health: An Integrative, Life History Framework
2016-01-11 00:00
Bruce Ellis: University of ArizonaLife history theory is used to explain how individuals adapt their physiology, behavior, and reproduction to different social and ecological conditions. Using a life history framework, I will present a program of research examining linkages between childhood experiences (including familial and extra-familial conditions), pubertal development, sexual activity, and health, highlighting the important distinction between harsh versus unpredictable environmental contexts, the special role of fathers in regulating daughters’ sexual development, differential susceptibility to environmental influences, and effects of life-history trade-offs on health. An evolutionary, life history perspective emphasizes that, when organisms encounter stressful environments, it does not so much disturb their development as direct or regulate it toward strategies that are adaptive under stressful conditions, even if those strategies are currently harmful in terms of the long-term welfare of the individual or society as a whole.

Brenna Henn - Answering Major Questions in Modern Human Origins with Genome Data
2016-01-04 00:00
Brenna Henn: SUNY Stony BrookOver twenty-five years ago, geneticists sequenced mitochondrial DNA from a diverse sample of human populations and hypothesized that all humans have a common origin in Africa 200,000 years ago.The broad outlines of this hypothesis remain remarkably unaltered, but many details of our African origin continue to be elusive. After decades of advances in human genetics, we are no longer data limited (either in terms of samples or genomic loci) but there is little consensus on most key issues. I will outline the models underlying the origin of modern humans. For example, was there a single ancestral population or multiple ancestral populations? Additionally, is there a discordance between anatomically modern humans and behaviorally modern humans? I will explore patterns of genetic diversity across Africa, the complex history of southern African KhoeSan groups and adaptations to African environments. I discuss whether genetic data supports archaeological data and suggest directions for future research.

Elizabeth Cashdan - Sex Differences in Mobility and Wayfinding: Cross-Cultural Perspectives
2015-11-30 00:00
Elizabeth Cashdan: University of UtahSex differences in range size and navigation are widely reported, with males traveling farther than females, being less spatially anxious, and, in many studies, navigating more effectively. We want to know why males range farther, and what this might tell us about sex differences in wayfinding and spatial confidence. Proposed evolutionary explanations have suggested that males gain mating benefits from large ranges (mating hypothesis), while females incur greater fitness costs from such travel due to parenting constraints (parenting hypothesis). We find support for both hypotheses, but a comparison of the polygynous Twe and the monogamous Maya suggests that the importance of the two hypotheses varies facultatively with mating patterns. Our work in Utah also indicates that women’s greater harm avoidance is a partial mediator of the sex difference in mobility, which in turn affects navigational style and ability.

Melissa Emery Thompson - On Less Fertile Ground: Chimpanzee Life Histories in Context
2015-11-23 00:00
Melissa Emery Thompson: University of New MexicoAmong the most dramatic changes to occur during human evolution were those affecting our life history. The evolution of the human fertility pattern, including relatively fast birth rates, overlapping offspring dependencies, and extended postreproductive life, remains an active area of research and debate that can be greatly informed by structured comparisons to the living apes. To do so effectively, we need high quality data from natural populations, as well as more detailed information about the physiological mechanisms that regulate fertility in both species. To that end, I will discuss empirical data on reproductive lifespan, determinants of fecundity, regulation of the interbirth interval, and parental investment in wild chimpanzees with comparison to human populations. Humans and chimpanzees share remarkably similar patterns for the regulation of fertility. Despite the relatively higher cost of human infants, human mothers appear less constrained by their reproductive systems than are chimpanzee mothers. These data support the view that the social context of reproduction has been a fundamental contributor to changes in life history.

Joey Cheng - Getting to the Top: Pathways to Social Rank
2015-11-16 00:00
Joey Cheng: University of Illinois at Urbana-ChampaignThe pursuit of social rank is a recurrent and pervasive challenge faced by individuals across human societies. Yet, the precise means through which individuals compete for social standing remain unclear. This talk examines the dynamics of two fundamental avenues—fear and respect—to social rank. I will begin by highlighting how these strategies differ—in terms of their characteristic personality, emotional, verbal, and nonverbal patterns. I will then present evidence demonstrating the viability of fear and respect for effectively ascending the social hierarchy in both the lab and the field. Finally, I will discuss new research that examines the impact of fear- and respect-based leadership on group functioning and follower well-being. Taken together, this emerging line of research suggests that fear and respect represent two distinct pathways to social rank. Underpinned by a unique suite of cognitive, affective, and behavioral processes, these pathways shape the hierarchical order of individuals within groups and promote collective success, albeit under different circumstances.

Elly Power - Signaling, Status, and Social Networks: Religious Practice in Rural South India
2015-11-09 00:00
Elly Power: Santa Fe InstituteDiscerning the intentions and character of others is a difficult task. In South India, religious practice is seen as particularly helpful in that process of discernment. There, the ritual acts undertaken are often quite dramatic: devotees walk across hot coals, pierce their skin with hooks and spears, walk barefoot to distant temples, and sacrifice animals to the divine. What is being communicated through these acts? Drawing on reputational and social support network data, I show that greater and costlier ritual participation corresponds to greater recognition not only for being devout, but also for holding a suite of prosocial traits. Perhaps more importantly, greater and costlier ritual participation also increases the likelihood of a supportive tie between individuals. These findings provide clear support for the costly signaling theory of religion. However, I will spend much of the talk complicating these simple relationships. Not everyone performs costly ritual acts, and the reputational benefits that accrue to those who do are not equally distributed. Much of this variation can be explained by the social risks entailed in these acts and the differential ability of villagers to take on those potential costs. To fully understand this signaling system, a broader understanding of cost, a wider range of actors, and a more complete inventory of signals (including not only the dramatic but also the subtle) must all be recognized and taken into account.

Drew Rendall - Language Evolution and The (Ir)relevance of Primate Communication
2015-11-02 00:00
Drew Rendall: University of LethbridgeThe evolution of language is a longstanding problem that continues to invite study, analysis, and speculation from a variety of perspectives. One perspective has been to adopt a comparative stance and seek the rudiments of key elements of language in the communication systems of closely related nonhuman primates. While sensible enough, in principle, I’ll argue that this search has been focused in the wrong places (like the drunk fumbling in the dark searching the ground for his keys, not where they’re most likely to be but rather simply where the light is brightest) namely on high-level informational properties of language related to its intentionality, semantics and syntax. Several decades of such focused research now points to the conclusion that, in these respects, primate communication is largely irrelevant. So, despite their phylogenetic proximity to us, are other primates in fact not really relevant to the problem of language evolution? I’ll answer, no… and promise to disambiguate that answer. In the process, I’ll hope to make some broader points about the enterprise of theorizing, both in this field but also more generally, considering how the constructs we use, the explanatory metaphors we borrow, and (ironically?) the language we adopt can steer the phenomena we study and aim to explain, as much as the reverse, potentially leading us to mistake purely theoretical entities for real ones.

Debra Martin - CANCELLED -- Ancient Bones, Ancestral Bodies: Interpretive Approaches to Violence and Behavior
2015-10-26 00:00
Debra Martin: University of Nevada, Las VegasViolence (lethal and nonlethal) is often associated with social spheres of influence and power connected to daily life such as subsistence intensification, specialization, resources, climate, population density, territorial protection and presence of immigrants, to name just a few. By using fine-grained biocultural analyses that interrogate trauma data in particular places at particular times in reconstructed archaeological contexts, a more comprehensive view into the behaviors, histories and experiences of violence emerges. Moreover, identifying culturally-specific patterns related to age, sex, and social status provide an increasingly complex picture of early small-scale groups. Some forms of ritual violence have restorative and regenerative aspects that strengthen community identity. Other forms of social violence cause rupture and disintegration at the group level. Bioarchaeological data can shed light on the ways that violence becomes part of a given cultural landscape. Viewed in a biocultural context, evidence of osteological trauma provides rich insights into social relationships and the many ways that violence is embedded within those relationships.

Tim Shields - The Demonstrability of What You Have Not Done (But Could Have) Matters In Trust-based Exchange
2015-10-19 00:00
Tim Shields: Chapman UniversityWe describe results of a study in trust-based exchange that supports the proposition that humans perceive intention not only through what others do but also through what others choose not to do. Crucial to this proposition is the notion that trust-based exchanges entail decision dilemmas where mutually exclusive goals are traded off and the forgone opportunities produce clues about our intent – affecting others’ reactions. To manipulate the availability of foregone opportunities, we used two versions of the trust game in a 1×2 between subjects design. In two experimental trust games, the action space governing trustors’ transfers was manipulated to examine the effects on trustors’ transfers and trustees’ returns. In the “all-or-nothing” game the trustor could transfer either $10 (all) or $0 (nothing), while in the “continuous” game the trustor could transfer any amount between $10 and $0. In both games, the trustee received the tripled transfer and then could return any amount (to trustor). Trustors transferred significantly more in the all-or-nothing game than in the continuous game. However, higher initial transfers in the all-or-nothing game did not lead to larger returns. To the contrary, conditional on $10 transfers, on average trustees returned significantly less in the all-or-nothing game than in the continuous game. Although the all-or-nothing action space results in greater wealth overall, trustors do not benefit from this increased wealth. These results suggest that the availability of alternative options is paramount in shaping social behaviors.

Erik Gjesfjeld - Social and Technological Responses to Risk and Uncertainty: A Material Culture Approach
2015-10-12 00:00
Erik Gjesfjeld: UCLAIn both the past and present, human populations are consistently presented with unpredictable situations. Behavioral responses to these situations are often heavily mediated by our degree of knowledge (uncertainty) about the variability in outcomes (risk). Using social network analysis as well as a novel macro-evolutionary method for examining the mode and tempo of evolution, this research explores changes in material culture diversity in response to increased environmental and economic risk. Results from this research suggest that social networks can be an important mechanism for reducing hunter-gatherer uncertainty surrounding environmental fluctuations, but technological innovations do not tend to buffer economic risk, as is commonly thought. Overall, these findings help to highlight some of the misconceptions surrounding risk and support the continued analysis of risk-sensitive adaptations using material culture.

Dan Franks - The Evolution of a Long Post-Reproductive Lifespan in Killer Whales
2015-10-05 00:00
Dan Franks: University of YorkWhy females of some species cease ovulation before the end of their natural lifespan is a longstanding evolutionary puzzle. In humans as well as some natural populations of cetaceans and insects, reproductive aging occurs much faster than somatic aging and females exhibit prolonged post-reproductive lifespans (PRLSs). Determining the mechanisms and functions that underpin PRLSs has proved a significant challenge. Here we bring together both classic and modern hypotheses proposed to explain PRLSs and discuss their application with particular reference to our studies of killer whales. In doing so we highlight the need to consider multiple interacting explanations for the evolution of PRLSs.

Kristin Snopkowski - Reproductive Decision-Making in Transitional Contexts
2015-09-28 00:00
Kristin Snopkowski: Boise State UniversityOver the past two hundred years, most societies around the world have experienced fertility transitions, defined as a dramatic decline in reproductive rates through time. The conscious decision to reduce fertility to very low levels appears maladaptive and poses a theoretical challenge to human behavioral ecologists who expect humans to maximize long term fitness. I develop a theoretical model to explain currently low fertility rates that incorporates both cultural and economic hypotheses of fertility decline and test these using data from San Borja, Bolivia, a society currently undergoing a fertility transition. Results show that both economic and cultural information are important determinants of reproductive decisions. Kin are also an important influence on reproductive decision-making, possibly providing help to a reproducing couple or hindering reproduction by engaging in resource competition. I test these hypotheses using data from Thailand and Indonesia and show that couples who receive help from kin are more likely to reproduce in the future, providing evidence for the cooperative breeding hypothesis. Finally, I present some preliminary results from my recent field season in Huatasani, Peru exploring men’s reproductive decision making and discuss theoretical models of sexual conflicts over family size.http://www.sscnet.ucla.edu/anthro/snopkowski-bec-talk.pdf

A.J. Figueredo and Michael Anthony Woodley - A Sequential Canonical Cascade Model of Social and Cognitive Biogeography
2015-06-01 00:00
A.J. Figueredo and Michael Anthony Woodley: University of Arizona, Free University of BrusselsA sequential canonical cascade model, detailing the hypothesized biogeography of human life history (LH) and intelligence (IQ), derives elevated levels of IQ through a series of causal steps, starting with the evolution of slower LH strategies based on both the physical ecology (climatological factors) and community ecology (population density and parasite burden). This model then examines the social ecology of slow LH strategy through the establishment of cooperative and mutualistic social systems with enhanced levels of social equality, within-group and between-group peace, and sexual equality. These social sequelae, in turn, lead to the strategic differentiation of resource allocation profiles among slower LH strategists (the SD-IE effect) that foster socioecological niche-splitting through intraspecific character displacement and produce mutual competitive release among individuals in saturated, resource-limited environments. By producing cooperative systems of specialists that each efficiently exploit different social micro-niches, the mutual exchange of resources so derived inevitably triggers the action of Ricardo’s Law of Comparative Advantage, producing greater aggregate wealth through these emergent social properties than would otherwise be attainable to equal numbers of generalists. We track this hypothesized mediating mechanism through the relations among three major macroeconomic indicators at the national level of aggregation: higher Economic Complexity Indices, lower Gross Domestic Product Dissimilarity Indices, and lower Krugman Dissimilarity Indices. Finally, we explain how this combination of powerful macroeconomic forces inevitably produces massive increases in aggregate wealth that elevate the collective human capital of the entire society, enhances physical brain volume, and contributes to higher overall levels of human cognitive abilities.

Jacob Foster - The Unknown Known: Science, Social Learning, and Cultural Evolution
2015-05-18 00:00
Jacob Foster: UCLAScience is an incredibly successful instance of social learning. Its practices produce and subtly organize the attention, effort, and creativity of millions of scientists, leading to rapid and cumulative cultural evolution. In this talk, I outline the striking convergence between this view of science and the one developed in science studies. Using data from millions of scientific papers, I illustrate how scientists use social cues to select research problems and how these heuristics lead to more (and less) efficient discovery. I then argue that formal theories of learning and cultural evolution shine new light on old puzzles in the sociology of science–while the study of science provides provocative problems, parallels, and paradigms for theories of cultural evolution.

Laurie Santos - The Evolution of Irrationality: Insights from Non-Human Primates.
2015-05-11 00:00
Laurie Santos: Yale UniversityI will explore the evolutionary roots of some of our species’ irrational decisions. I will start by reviewing some classic biases in the field of judgment and decision-making and will then turn to the question of how these biases came about in the first place by exploring some recent experiments in exploring similar biases in monkeys. I will then discuss new work suggesting ways that the human species is uniquely irrational.

Lera Boroditsky - How the Languages We Speak Shape the Ways We Think
2015-05-04 00:00
Lera Boroditsky: UCSDHow do the languages we speak shape the ways we think? Do speakers of different languages think differently? Does learning new languages change the way you think? Do bilinguals think differently when speaking different languages? Does language shape our thinking only when we’re speaking or does it shape our attentional and cognitive patterns more broadly? In this talk, I will describe several lines of research looking at cross-linguistic differences in thought.

Emma Cohen - Social Bonding in Movement and Exercise
2015-04-27 00:00
Emma Cohen: University of OxfordIn this talk, I’ll present some ideas and preliminary data on the links between exercise and social bonding. Exercise, broadly construed, is a cultural universal – from ceremonial rituals to team sports, people everywhere get together to move together. Our research investigates whether and how such activities serve a social bonding function, as has been long claimed in the social scientific literature. Specifically, we explore the social bonding effects of behavioural coordination and exercise ‘highs’. We are also interested in the effects of social bonding on exercise ability and performance, particularly on pain perception and fatigue thresholds. The research attempts to reveal mechanisms underlying the links between coordinated movement, pleasure and pain, and bonding and wellbeing and thereby to contribute new data on a pervasive feature of everyday life that cross-cuts cultural domains as varied as religion, sport and play.
