Center for Behavior, Evolution, and Culture

Chris Guzelian - Evolution, Selfish Lies, and Free Speech
2006-04-17 00:00 (America/Los_Angeles)
Chris Guzelian: Searle Scholar, Northwestern University School of LawEvidence increasingly suggests that selection between competing ideas to become a prevailing social belief may be strongly influenced by evolutionarily descended limitations on human sensory and mental capabilities. Scholars posit that these limitations permit many “selfish” ideas to gain social traction and spread epidemically, driving out and shutting out truth from collective understanding in the selection process. An evolutionary perspective, combined with settled principles of free speech law, indicates that the explicit combating of various selfish false ideas through technological, educational, legal, financial, or other means may be necessary to avoid self-sustaining mass delusions in a globalizing world.

Joseph Campos - On the Epigenesis of Fear in the Human Infant
2006-04-24 00:00
Joseph Campos: UC Berkeley Department of PsychologyThere is a fascinating paradox about fear of heights in humans and some animal species. Such fear has enormous biological adaptive value, represents a true life-span emotional reaction, and constitutes one of the strongest and most reliably-elicited fears in the human. As such, one would expect fear of heights to be innate, or under strong maturational control. Indeed, until recently, it was so considered. However, there is now no doubt that fear of heights develops as the result of experience, more specifically experiences linked to the onset of self-produced locomotion. It is not a maturational or innate event.
What creates fear of heights and how does locomotor experience play a role in its ontogeny? We can rule out three likely candidates as playing a causal role. Depth perception is well established before such fear develops; falling experiences are relatively rare; and maternal emotional signaling has little if any impact at the age of onset of locomotion. What, then, may be the process(es) by which such biologically-adaptive wariness comes about?
In this talk, evidence is presented for the role of a discrepancy between sensory systems in the ontogeny of these fears. The discrepancy we propose to be playing a causal role is related to the discrepancy that in adults makes heights â€œdizzying.â€ More specifically, one experiences height vertigo when information reaches the brain that the head and body is moving (even minutely so), but visual information discrepantly fails to confirm such self-movement. It turns out that infants have good vestibular and kinesthetic information about self-movement from early in life, but lack responsiveness to flow in the visual periphery until after the acquisition of locomotor experience. So, only after â€œvisual proprioceptionâ€ becomes functional is the infant capable of experiencing the discrepancy that produces height vertigo.
The talk will:
(a) Visually illustrate what visual proprioception is (it is not a phenomenon well-known to behavioral scientists),
(b) Provide evidence for the role of locomotor experience on visual proprioception, and
(c) Present results of two studies showing correlations between responsiveness to optic flow and the probability of showing wariness of heights in infants at two different ages.http://www.bec.ucla.edu/papers/Campos_24.4.06.doc

Nancy Burley - Sexual Imprinting: New Approaches to an Old Problem
2006-05-01 00:00
Nancy Burley: UC Irvine Department of Ecology & Evolutionary BiologySexual imprinting, a process by which early contact with parents shapes the mate preferences of developing young, has been widely documented among birds and has been reported for other vertebrates, especially mammals (including humans). Historically, studies of imprinting have emphasized causal and ontogenetic perspectives, with function and evolutionary consequences receiving less attention. Recent quantitative models have investigated a possible role for sexual imprinting in vertebrate speciation processes, but little empirical support for this possibility has been provided. Moreover, recent studies suggest that sensory drive processes exert strong, unlearned influences on mate preferences which might override tendencies to imprint on novel traits that emerge in incipiently diverging populations. Here I report results of several experiments designed to evaluate the tendency of both sexes of zebra finches to imprint on novel traits of parents with otherwise normal phenotypes. The novel (experimental) traits are crests of various colors and patterns. Previous research (Burley & Symanski 1998) indicates that female zebra finches reared with wild-type (uncrested)parents have sensory biases favoring white-crested males; normally reared males lack this bias and favor uncrested females. By rearing young with crested parents, I investigated how sensory drive and imprinting processes interact. Results suggest that imprinting responses of both sexes may vary considerably with the perceived information content of experimentally manipulated traits, and that some evolutionarily novel traits may promote reproductive isolation in diverging populations.http://www.bec.ucla.edu/papers/Burley_5.1.06.pdf

Michael Shermer - Evonomics: Natural Selection, the Invisible Hand, and the New Science of Evolutionary Economics
2006-05-08 00:00
Michael Shermer: Skeptic MagazineThere are a number of parallels between evolution and economics that we shall explore on two tiersâ€”historical and theoretical: the parallels between natural selection and the invisible hand; the nature of evolution and the characteristics of a free market economy; the reluctance to accept the theory of evolution and free market economics; evolution and economics as emergent properties; how evolution shaped economic behavior; and contingency in evolution and path dependency in economies. In short, natural selection and the invisible hand are analogous descriptors for analogous phenomena.

Bruce Winterhalder - Seven Reasons to Remain a Forager
2006-05-15 00:00
Bruce Winterhalder: UC Davis Department of AnthropologyArchaeological research shows that many human populations continued to hunt-and-gather for thousands of years after beginning the use of plant domesticates. This kind of mixed economy is rare in the ethnographic literature on foragers and horticulturalists; its persistence for millennia in the early stages of agricultural origins is inexplicable under much current theory. In this paper I describe models and concepts from evolutionary anthropology which may help us to explain this novel,persistent, prehistoric mode of production. The more important ones include (a) the population ecology of the domesticates themselves, (b) environmental fluctuation, (c) temporal discounting of subsistence options, (d) maintenance of technological knowledge in low-density populations, and (e) institutional mechanisms of risk-manage under changing economic regimes. Collectively these ideas are meant to demonstrate, contra Sahlins and substantivism, the utility of a selective set of micro-economic concepts in the study of pre-market economies.

Robert Hoffmann - Religion, Religiosity and Cooperation: An Experimental Study from Malaysia
2006-05-22 00:00
Robert Hoffmann: Department of Economics, Nottingham University Business School, The University of NottinghamHuntington’s notion of a clash of cultures has attracted a great deal of attention in recent years. In particular, religious differences as well as religious fundamentalism have been identified as crucial dimension of present culture clashes. We conducted a study to explore to what extent different religions and religiosity affect the economic interactions between individuals as a test of this notion. The study is based on religious attitude surveys and incentivised economic experiments with repeated prisoner’s dilemma play among Malaysian subjects. The multi-ethnic nature of Malaysia is ideally suited to match subjects for game play from the world’s major religions (Islam, Catholicism, Protestantism, Hinduism and Buddhism) while holding other socio-economic factors constant.

Dacher Keltner - Evolution's Soul: What Laughter, Smiling, Lip Puckers, and Goosebumps Tell us About the Evolution of Human Goodness
2006-05-29 00:00
Dacher Keltner: UC Berkeley Department of PsychologyIn this talk I will present recent work on the pro-social emotions. I will present studies of smiling, the relations between oxytocin and the nonverbal displays of love and desire, and recent evidence exploring the role of vagus nerve activity in compassion and pro-social dispositions. I will use these data to offer the beginnings of a theory of the emotion-related origins of pro-sociality, drawing upon Darwin’s own speculations and those of recent philosophers and behavioral scientists.

Wendy Treynor - Are the Most Mistrustful the Least Trustworthy? Studies of Unethical Behavior
2006-10-09 00:00
Wendy Treynor: USC Institute for Creative TechnologiesIs one who believes that unethical activity is common unlikely to act ethically? To test the hypothesis that cynical beliefs predict unethical behaviors, actual unethical activity was examined by developing two laboratory techniques. In the American History Aptitude Test cheating technique, participants were told they would be rewarded with 10 cents for each question on a test that â€œaccidentallyâ€ had the correct answers already marked on it, whereas in the Weight Perception Task stealing technique, participants estimated the weight of objects using coins from a bowl, which they sat alone with, containing $71.00 of coins. Regardless of technique used, cynicismâ€”the belief that
others are engaging in unethical acts or that unethical behavior is common or normalâ€”was found to positively predict unethical behavior.

Andreas Wilke - The adaptive problem of finding resources
2006-10-16 00:00
Andreas Wilke: UCLA Department of AnthropologyWhen resources are distributed in patches animals must decide when to switch from a depleted patch. The optimal policy is given by the Marginal Value Theorem, which has successfully predicted animal behaviors, but as a mechanism it becomes problematic when each patch contains few discrete prey items. Biologists have proposed simple alternative decision mechanisms and calculated in which environments each works well. We tested whether the decision mechanisms evolved to direct animals when to leave a food patch also underlie human decision making in the same context, and whether humans in an internal-search task (e.g. information in memory) use the same mechanisms as in an external-search task (e.g. physical objects).

Colin Camerer - Status, ethnicity, and wealth in Vietnam: Evidence from experimental games
2006-10-23 00:00
Colin Camerer: CalTech Department of Business EconomicsWe conducted economic experiments to investigate interethnic discrimination with the members of three ethnic groups, i.e., Vietnamese, Khmer and Chinese, in southern Vietnam. Vietnamese are the major ethnic group, and Khmer and Chinese are main minority groups. Chinese are the richest and Khmer are the poorest among the three ethnic groups.
We found that 1) Khmer (poor minority) show the strongest solidarity. 2) Vietnamese (majority) do not show solidarity when they are matched with Khmer (poor minority), but demonstrate ingroup bias when they are matched with Chinese (rich minority). 3) Vietnamese often comply with the social norm of fair allocations, choosing equal splits both in Dictator Game and Third Party Punishment Game. 4) Khmer send much more in Third party Punishment game than in Dictator Game, while Chinese reduce the amount sent when the third party is introduced (crowing-out effects). 4) Both minorities punish Vietnamese more severely when Vietnamese violate the norm. 5) Both minorities protect ingroup victims more than they do outgroup victims.

Mark Changizi - Letters from nature
2006-10-30 00:00
Mark Changizi: CalTech Sloan-Swartz Center for Theoretical NeurobiologyReading pervades every aspect of our daily lives, so much so that one would be hardpressed to find a room in a modern house without words written somewhere inside. Many of us now read more sentences in a day than we listen to. Not only are we highly competent readers, but our brains even appear to have regions devoted to recognizing words. A Martian just beginning to study us humans might be excused for concluding that we had evolved to read. But, of course, we havenâ€™t. Reading and writing is a recent human invention, going back only several thousand years, and much more recently for many parts of the world. We are reading using the eyes and brains of our illiterate ancestors. Why are we so good at such an unnatural act? Here I describe new evidence that, although we have not evolved to be good at reading, writing appears to have culturally evolved to be good for the eye. More specifically, new research supports the hypothesis that human visual signs look like nature, because that is what we have evolved over millions of years to be good at seeing. This ecological hypothesis for letter shape not only helps explain why we are such good readers, but answers the question, Why are letters and other visual signs shaped the way they are?http://www.bec.ucla.edu/papers/Changizi_10.30.06.pdf

Paul Bloom - Bodies and Souls
2006-11-06 00:00
Paul Bloom: Yale Department of PsychologyHow do we think about bodies and souls? Findings from developmental psychology suggest that both children and adults see physical entities such as objects (or bodies) as fundamentally distinct from psychological entities such as minds (or souls). We are natural-born dualists. Our dualism explains why we are so drawn to certain religious beliefs — such as life after death and the existence of supernatural entities — and it also underlies certain aspects of moral reasoning.

Michael Cannon - Modeling the Tradeoff between Foraging and Farming
2006-11-13 00:00
Michael Cannon: CSU Long Beach Department of AnthropologySome archaeologists have used a model of optimal time allocation from human behavioral ecology to help explain variability over space and time in the importance of farming vs. foraging. I discuss a model that builds on this previous work in an effort to enable a more detailed understanding of the factors relevant to the development of prehistoric agriculture. This model is more explicit about the activities involved in agriculture, modeling the costs and benefits of harvest-producing activities and post-harvest processing activities separately; this potentially provides a means for integrating labor division into the model. The model also enables a consideration of the roles that both mean productive efficiency and variability in production might play in the evolution of agricultural economies. Model predictions are evaluated against archaeological data from the American Southwest to clarify the factors that underlay increases in the importance of agriculture in this region.

Joan Silk - The origins of prosocial preferences
2006-11-20 00:00
Joan Silk: UCLA Department of AnthropologyHumans differ from most other animals, and from virtually all other primates, in the extent of our dependence on cooperation. In humans, altruism seems to be at least partly based on empathy and genuine concern for the welfare of others (Batson and Powell 1998; Fehr and Fischbacher 2003). We may also be motivated by a concern for reputation (Haley and Fessler 2005), that makes us want others to think that we are generous, fair, or charitable. Nonhuman primates also act altruistically, but the extent and deployment of altruism in primate groups is much more limited than it is in human societies. Altruistic interactions usually involve very small numbers of individuals (usually dyads) and is strongly biased by kinship. There is some evidence for reciprocity among unrelated individuals, but these exchanges are generally restricted to short-term exchanges of low-cost commodities. It is not clear what limits altruism in nonhuman primate groups. New work suggests, however, that differences in the deployment of altruism in human and nonhuman primate may be linked to differences in the capacity for empathy, the existence of moral sentiments, and the concern for the welfare of others.

Peter Richerson - The Role of Religion in Human Cooperation: Experiments Using Economic Games
2006-11-27 00:00
Peter Richerson: UC Davis Department of Environmental Science and PolicyReligion is often held to play a large, even dominant, role in supporting human cooperation. Much variation in propensities to cooperate and treat others fairly exists within and between human societies. Previous work by social psychologists suggested that religion plays a small role in explaining this variation, but the validity of the dependent variables used is questionable. We used behavior in Dictator, Trust, and Public Goods games as dependent variables to test for the effects of a wide variety of measures of religious participation, experiences, beliefs, and affiliation on cooperation and other prosocial behaviors. Despite the data-dredging aspects of our experimental design, we found significant effects of religious variables on prosocial behavior. Further, various dimensions of religiosity correlated with game behavior in a way that is somewhat consistent with findings from the experiments devised by social psychologists. However, we found little evidence an “ingroup” effect; participants did not send more money to individuals with similar religious preferences. By comparing numerous models using an information-theoretical approach, we draw some general conclusions about which theories are data are most likely to support.

Dario Maestripieri - Biological bases of caregiver attachment
2006-12-04 00:00
Dario Maestripieri: University of Chicago Department of Comparative Human DevelopmentIn human and nonhuman primates, caregiver attachment is a motivational/ behavioral system that promotes the maintenance of proximity between a caregiver and an infant and facilitates the expression of caregiving behavior. Comparative data on female interest in infant and infant-directed behavior in nonhuman primates and humans will be used to illustrate the proximate regulation, development, adaptive function, and evolution of the caregiver attachment system.

Rob Boyd - Reciprocity is not sufficient to explain human cooperation
2007-01-08 00:00
Rob Boyd: UCLA Department of AnthropologyRecent discussions of human cooperation assume that the theory reciprocal altruism provides an established explanation for human cooperation, and that therefore, alternative explanations invoking cultural group selection face a burden of proof. In this talk, I argue that this assumption is not justified. The theory of reciprocal altruism does predict that cooperative behavior among small groups of unrelated individuals will evolve, but this theory is not supported by most empirical data. The theory of reciprocal altruism also predicts that cooperative behavior is evolutionarily stable, but also predicts that any other behavior is equally likely to be stable, and thus does not provide a sufficient explanation for the commonness of large scale human cooperation. I also argue that the theory of cultural group selection is cogent, and consistent with much empirical data.

Wendy Saltzman - Endocrinology of Female Reproductive Competition in Cooperatively Breeding Marmoset Monkeys
2007-01-22 00:00
Wendy Saltzman: UC Riverside Department of BiologyCommon marmosets are cooperatively breeding monkeys that exhibit high female reproductive skew: typically only a single, dominant female breeds successfully in each social group. Laboratory studies have indicated that reproductive suppression in subordinate females is not aggressively imposed on them by dominant females and is not associated with stress; instead, it is mediated by a specific, presumably adaptive neuroendocrine mechanism. Moreover, subordinate females readily begin to breed under favorable conditions, such as following introduction of an unrelated male into the group, and show no impairments in their ability to maintain pregnancy or successfully produce offspring. When two females breed concurrently, however, they engage in overt reproductive competition, with pregnant females commonly killing one anotherâ€™s infants. In sum, our findings are consistent with recent manipulation-based models of reproductive skew, in which reproductive suppression in non-breeders is mediated, mechanistically, by self-restraint but has evolved in response to selection â€“ namely, infanticide â€“ imposed by breeding females.http://www.bec.ucla.edu/papers/Saltzman_1.22.07.pdf

Alex Mesoudi - Towards a unified science of cultural evolution: A brief theoretical background and some experimental examples
2007-02-05 00:00
Alex Mesoudi: University of British Columbia W. Maurice Young Centre for Applied EthicsA Darwinian theory of cultural evolution holds that the same fundamental principles that govern biological change â€“ variation, selection and inheritance â€“ also underlie human cultural change. In fact, the empirical case for cultural evolution is now as strong as the case that Charles Darwin presented in The Origin of Species for biological evolution (Mesoudi, Whiten & Laland, 2004). Consequently, similar tools, methods and theories that biologists use to study biological evolution can be adapted to study cultural change, and the structure of the science of biological evolution â€“ evolutionary biology â€“ can serve as a model for the structure of a science of cultural evolution (Mesoudi, Whiten & Laland, 2006).
One branch of this science of cultural evolution is the experimental study of cultural transmission, which uses the methods of social psychology to identify systematic biases that affect the transmission of information through groups of people. For example, Mesoudi, Whiten and Dunbar (2006) found that information regarding social relationships is transmitted with greater fidelity than equivalent non-social information, consistent with â€œMachiavellian intelligenceâ€ hypotheses of primate brain evolution. Mesoudi and Oâ€™Brien (submitted), meanwhile, simulated the cultural transmission of arrowhead designs, matching different transmission biases to actual patterns of prehistoric arrowhead variation in the archaeological record. This integration of individual-level transmission biases and population-level archaeological patterns is facilitated by an evolutionary approach to human culture.http://www.bec.ucla.edu/papers/Mesoudi_2.5.07.pdf

Pascal Boyer - Why do patients and religious people perform rituals?
2007-02-12 00:00
Pascal Boyer: Washington University Department of PsychologyRitualized behavior is found in children’s typical development, as well as in the pathology of OCD and in cultural ceremonies. Pierrre Lienard and I proposed elsewhere a neurocognitive model of ritualized behavior in human development and pathology, as based on the activation of a specific hazard-precaution system specialized in the detection of and response to potential threats. I argue that certain features of collective ritualsâ€¹by conveying information about potential danger and presenting appropriate reaction as a sequence of rigidly described precautionary measuresâ€¹probably activate this neurocognitive system. This makes some collective ritual sequences highly attention-demanding and intuitively compelling and contributes to their transmission from place to place or generation to generation.

Karl Sigmund - Between freedom and enforcement: public goods and costly punishment
2007-02-15 00:00
Karl Sigmund: University of Vienna Department of MathematicsA considerable body of theoretical and empirical evidence underlines the important role of punishment in stabilising high contributions to joint enterprises. But how does punishing behaviour emerge? This talk highlights the role of voluntary participation. Analytical methods and individual-based simulations show that social norms including the punishment of exploiters can emerge more easily if it is possible to abstain from the joint enterprise.

Susan Carey - The Origin of Concepts: The Case of Natural Number
2007-02-26 00:00
Susan Carey: Harvard Department of PsychologyI make two non-controversial assumptions about human conceptual understanding. First, it is built from a shared set of developmental primitives–the representational resources bequeathed to all human beings by evolution. Equally obviously, human cultures create new representational resources, transcending these initial ones in format, content and expressive power, which are turn internalized by individuals in the course of conceptual development. These assumptions, even if granted, leave open radically different possibilities concerning the processes of conceptual development and the scope for cross-cultural variation. How rich are the developmental primitives? How constraining of adult cognition are they? Does human conceptual development require transcending the initial state, and if so, what mechanisms make this possible? .
I will illustrate an empirical research program addressing this space of theoretical options in the domain of numerical cognition, focusing on the developmental primitives with numerical content, the cultural construction of integer representations, and the bootstrapping processes that allow each child to transcend their initial representational resources, creating representations of natural number.

Bernard Comrie - Vertical and horizontal transmission of language structure
2007-03-05 00:00
Bernard Comrie: Max Planck Institute for Evolutionary Anthropology Department of Linguistics & UC Santa Barbara Department of LinguisticsAn understanding of the transmission of language across time requires reference to both vertical transmission – for instance, the English word “father” is a direct inheritance from the ancestral language Proto-Indo-European – and horizontal transmission – “paternal” was taken from Latin in the medieval period. This applies not only to vocabulary but also to language structure (grammar). The recently completed project The World Atlas of Language Structures (www.wals.info) for the first time provides the possibility of investigating such relations in detail. The talk will refer specifically to structural features that seem more amenable to either vertical or horizontal transmission, and include discussion of linguistic areas like Southeast Asia that result from widespread horizontal transmission and of the kinds of historical signals that can be detected in comparing structural information from languages of sub-Saharan Africa.

Brenda Bowser - Learning and Transmission of Pottery Style: Women's Life Histories and Communities of Practice in the Ecuadorian Amazon
2007-03-12 00:00
Brenda Bowser: Cal State Fullerton Department of AnthropologyThis paper examines the transmission of stylistic behavior in the community of Conambo. The people of Conambo are self-sufficient horticultural foragers who are strongly divided into two competing coalitions with flexible membership and defections across the coalitional boundary. The women of Conambo maintain a domestic polychrome ceramic tradition absent from external market influences. Previous studies show that pottery design in Conambo is understood and used strategically as a marker of group membership. In this paper we report age and status differences in perception and transmission of stylistic behavior, indicating that women’s pottery style and strategies of signification track life-history changes in their political relationships with in-group and out-group allies. We argue that in Conambo the transmission of ceramic design is influenced by the political strategies of women throughout their lives.

Daniel J. Kruger - Sexual selection, male competition, and sex differences in human mortality rates
2007-03-19 00:00
Daniel J. Kruger: University of Michigan School of Public HealthSex differences in human mortality rates stem from genetic, physiological, behavioral, and social causes that are best understood when integrated in an evolutionary life history framework. Males in many species are selected for riskier physiological and behavioral strategies that enhance reproductive success at the expense of health and longevity. Sex differences shaped by sexual selection interact with the environment to yield a pattern with some consistency, but also with expected variations due to socioeconomic and other factors. This presentation investigates the notion that sex differences in human mortality rates are related to levels of male competition for resources, social status, and mates, and that the actual or potential degree of skew in resource control will influence the degree of male competition and excess male mortality.http://www.bec.ucla.edu/papers/Kruger_3.19.07.pdf

Paul Griffiths - The Baldwin effect and genetic assimilation
2007-04-02 00:00
Paul Griffiths: University of Queensland Department of PhilosophyMany evolutionary processes have been described in which a trait that initially develops in the members of a population as a result of some interaction with the environment comes to develop without that interaction in their descendants. Waddingtonâ€™s genetic assimilation is importantly different from the rest of this â€˜Baldwinianaâ€™ because his explanatory focus was not on the selection pressures at the point of transition, but on how developmental systems come to be structured in such a way that these evolutionary transitions are readily accessible to evolving lineages. Waddingtonâ€™s approach also replaces the simple contrast between â€˜acquiredâ€™ and â€˜innateâ€™ with a non-dichotomous model of developmental canalisation and phenotypic plasticity that is in line with recent work on the evolution of development. From a Waddingtonian perspective evolutionary transitions between â€˜innateâ€™ and â€˜acquiredâ€™ are only to be expected because those categories have little meaning in terms of developmental genetics and in some cases the difference between the â€˜innateâ€™ and â€˜acquiredâ€™ may require only a minimal change in developmental mechanisms. But to see this it is necessary to use a gene concept suitable for thinking about development, and not a gene concept designed for theoretical population genetics or for the prediction of phenotypic differences within populations.http://www.bec.ucla.edu/papers/Griffiths_2.4.07.doc

Hillard Kaplan - The human adaptive complex and the evolution of the 70 year lifespan
2007-04-09 00:00
Hillard Kaplan: University of New Mexico Department of AnthropologyThis paper will present an overview of age-specific mortality rates among hunter-gatherers and forager-horticulturalists. It will also present new data on resource transfers and physical rates of aging among Tsimane forager-horticulturalists in Bolivia. It will be argued that the balance of costs and benefits of maintenance and repair of the human soma have resulted in a modal adult age at death of 70 or so years. Seven decades of life may be considered the evolved species-typical lifespan of Homo sapiens.

Caitlin O'Connell-Rodwell - The Importance of Communication and Culture to the African Elephant
2007-04-16 00:00
Caitlin O’Connell-Rodwell: Stanford University Department of Otolaryngology, Head and Neck SurgeryThe structure of African elephant society is primarily matriarchal in nature, where dominant female elephants make decisions for the herd as a whole with regard to safety, movements, resource choices and affiliations. Culture is often influenced by local environmental and social pressures, as well as the character of individual herd members. Aspects of elephant society that contribute to survival will be discussed in the context of mechanisms that elephants employ to communicate over long distances. In addition, new findings about elephant bull society will be reviewed, highlighting the importance of bonding and mentoring adolescent delinquent males.http://www.bec.ucla.edu/papers/OConnellRodwell_4.16.07.pdf

Joan Silk - Sex Ratio: Local Resource Competition and Local Resource Enhancement
2007-04-23 00:00
Joan Silk: UCLA Department of Anthropology

Nicola S. Clayton - Memories of Tomorrow: Do Animals Remember the Past and Plan for the Future?
2007-04-25 00:00
Nicola S. Clayton: University of Cambridge Department of Experimental PsychologyAccording to the mental time travel hypothesis only humans can mentally dissociate themselves from the present, travelling backwards in time to recollect specific past events about what happened where and when (episodic memory) and travelling forwards in time to anticipate future needs (future planning). Studies on the behaviour of food-caching western scrub-jays question this assumption. In terms of retrospective cognition, these birds remember the ‘what, where and when’ of specific past caching episodes, they keep track of how long ago they cached different types of perishable foods that decay at different rates, and also remember whether another individual was present at the time of caching, and if so, which bird was watching when. Recent work demonstrates that the jays also make provision for a future need, caching more food in places in which they will not be given breakfast the next morning than in places where they will be receive breakfast the next morning even though there is plenty of food available to them when they cache the food. Taken together these results challenge the mental time travel hypothesis by showing that some elements of both retrospective and prospective mental time travel appear not to be uniquely human.http://www.bec.ucla.edu/papers/Clayton_4.25.07a.pdf
