Center for Behavior, Evolution, and Culture

Morten Christiansen - The Evolution of Languages and Genes
2005-06-06 00:00 (America/Los_Angeles)
Morten Christiansen: Cornell University Department of Psychology Language is undoubtedly governed by innate constraints. Otherwise, it is difficult to account for the close match between the intricate structure of languages and the mechanisms involved in acquiring and processing them. Innate constraints are also needed to explain the existence of language universals; that is, why languages tend to be structured and used in certain ways and not others. Moreover, no other animal communication system appears to have the same kind of complex linguistic properties as found in human language. But does this necessarily mean that humans have evolved genes specifically to encode innate constraints on language? In this talk, I argue that such ‘language genes’ are an unlikely outcome of human evolution. Instead, corroborated by a series of language evolution simulations, I suggest that the exquisite fit between humans and language has arisen because languages themselves have evolved to fit human learning mechanisms existing prior to the emergence of linguistic communication. On this account, the apparently ‘idiosyncratic’ language universals derive from non-linguistic constraints on learning and processing in these mechanisms, many of which have evolved specifically to support complex human cognition.http://www.bec.ucla.edu/papers/Christiansen_6.6.05_1.pdf

Douglas Wallace - Human Origins, Genes and Myths: A Mitochondrial DNA Journey
2005-05-23 00:00
Douglas Wallace: UC Irvine Department of Ecology and Evolutionary BiologyThe investigation of human origins and migrations has been greatly advanced by the analysis of human genetic variation to determine the relationships between different human populations. Such studies have permitted demonstration of the recent African origin of humans, the reconstruction of ancient migrations, and the correlation of human genetic history with linguistic affiliations. The first component of the human genome to be used in these investigations was the maternally-inherited human mitochondrial DNA (mtDNA) which codes for key proteins involved in the conversion of dietary calories in into ATP to fuel work and heat to maintain our body temperature. Variation in the human mtDNA has been found to be encompassed in a single dichotomously branching tree with the different branches of the tree correlating dramatically with the geographic distribution of indigenous peoples from around the world. The mtDNA correlation with human populations is much greater than that seen for either the paternally-inherited Y chromosome or the biparentally inherited autosomes. We now believe that this correlation is because variation in the mtDNA permitted our ancestors to adapt to the increasingly cold environments that they encountered as they migrated out-of-Africa and into temperate Eurasia and arctic Siberia. Hence, selection has stabilized the geographic distribution of mtDNA variation such that mtDNA variation has sustained the distribution of the earliest human incursions around the world. This unique aspect of the mtDNA now makes mtDNA variation a particularly valuable tool for the analysis of deep cultural associations and origins. This is currently proving to be the case in studies on the origins and radiation of Native America languages and myths.http://www.bec.ucla.edu/papers/Wallace_23.5.05_1.pdf

Piotr Winkielman - Unconscious Emotion
2005-05-16 00:00
Piotr Winkielman: UC San Diego Department of PsychologyMy talk explores the relation between emotion and conscious experience. Conscious feelings are typically viewed as a central and necessary ingredient of emotion. In contrast, I will argue that emotion also can be genuinely unconscious (i.e., occur without the accompanying subjective experience). Theoretically, my argument is anchored in evolutionary considerations that systems underlying basic emotions originated prior to systems for supporting conscious awareness, and in functional considerations that consciousness is often unnecessary for emotions to do their job. These considerations are consistent with evidence from neuroscience and psychology. Neuroscience evidence suggests that subcortical brain systems, including the brain stem and the â€œlimbic systemâ€ underlie both basic â€˜â€˜liking/dislikingâ€™â€™ reactions and more complex reactions, such as fear, disgust, or desire. Further, psychological evidence suggests that positive and negative reactions can be elicited subliminally and remain inaccessible to introspection. Despite the absence of subjective feelings in such cases, subliminally induced affective reactions still influence peopleâ€™s preference judgments, monetary decision and even complex behavior, such as the amount of beverage they consume. Finally, I will discuss the interactions of conscious and unconscious components of emotion, and conditions under which these components become coupled and decoupled.http://www.bec.ucla.edu/papers/Winkielman_16.5.05_b.pdf

Jennie Pyers - Building belief: The relationship between language and theory of mind understanding in learners of an emerging sign language in Nicaragua
2005-05-09 00:00
Jennie Pyers: UC Berkeley Department of PsychologyFalse-belief understanding is the non-egocentric ability to recognize that one’s own thoughts and beliefs can be different from others’, and
different from real-world events (i.e., mistaken). Research on early child development suggests that false-belief understanding is contingent
upon language development. Recent findings from an emergent sign language in Nicaragua suggest that deaf individuals exposed to a less
complex version of the language show deficits in false-belief understanding, whereas those exposed to a more complex version of the
language develop normally. Without complex language, human interaction is insufficient to support the development of a mature social
understanding, specifically that of false belief.

Brian Lickel - Affective Mechanisms for Managing Intergroup Retribution
2005-05-02 00:00
Brian Lickel: University of Southern California Department of PsychologyIn this talk, Iâ€™ll present data examining how people think about and react to the wrong-doing of ingroup members. In particular, Iâ€™ll describe affective reactions of self-blame (shame, guilt, ingroup directed anger) that people sometimes experience when a member of their ingroup harms an outgroup. I argue that these affective reactions exist as a functional response to the problem of group-based or collective responsibility (e.g., blood revenge) and I will describe how the behavior that results from feelings of shame, guilt, or ingroup directed anger may reduce the extent to which a harmed outgroup engages in retaliation after a provocation.

Sang-Hee Lee - Old Is Young: Longevity in Human Evolution
2005-04-25 00:00
Sang-Hee Lee: UC Riverside Department of AnthropologyIncreased longevity, expressed as number of individuals surviving to older adulthood, represents one of the ways the human life history pattern differs from other primates. We assessed changes in longevity with the ratio of older to younger adults (OY ratio) in four hominin dental samples from successive time periods, and determining the significance of differences in these ratios. While there is significant increased longevity between all groups indicating a trend of increased adult survivorship over the course of human evolution, there is a dramatic increase in longevity in the modern humans of the Early Upper Paleolithic. We then addressed whether longevity increased as a result of cultural/adaptive change in Upper Paleolithic Europe or whether it was introduced to Europe as a part of modern human biology, comparing Western Asia and European samples. We find that the Upper Paleolithic OY ratio is more than double that of the Middle Paleolithic moderns; in contrast, the OY ratios of the two West Asian Middle Paleolithic groups are not significantly different from each other. However, the OY ratios of both West Asian Moderns and Neandertals are significantly higher than the European Neandertal ratio. Considering cultural versus taxonomic differences, we conclude that the increase in adult survivorship associated with the Upper Paleolithic may reflect an important cultural adaptation promoting the demographic and material representations of modernity. Further research is discussed.http://www.bec.ucla.edu/papers/Lee1_4.25.05.pdf

Raymond Gibbs - Embodied metaphor in language, thought, and culture
2005-04-18 00:00
Raymond Gibbs: UC Santa Cruz Department of PsychologyMetaphor is traditionally viewed as a special use of language. But recent research from cognitive linguistics and psycholinguistics suggests that metaphor is ubiquitous in language and a fundamental part of human conceptual systems. I will argue in this talk that metaphor is also deeply rooted in recurring aspects of embodied experience that serves as the grounding for significant parts of language, thought, and culture. Particular attention is given to recent experimental evidence showing that metaphor use arises from embodied simulations that people engage in during in-the-moment reasoning, speaking, and understanding.

Daniel M.T. Fessler - Cringing before others' eyes: A cross-cultural investigation of the evolution of shame
2005-04-11 00:00
Daniel M.T. Fessler: UCLA Department of AnthropologyCross-cultural comparisons can a) illuminate the manner in which cultures differentially highlight, ignore, and group various facets of emotional experience, and b) shed light on our evolved species-typical emotional architecture. In many societies, concern with shame is one of the principal factors regulating social behavior. Three studies conducted in Bengkulu (Indonesia) and California explored the nature and experience of shame in two disparate cultures. Study 1, perceived term use frequency, indicated that shame is more prominent in Bengkulu, a collectivistic culture, than in California, an individualistic culture. Study 2, comparing naturally occurring shame events (Bengkulu) with reports thereof (California), revealed that shame is associated with guilt-like accounts in California but not in Bengkulu, and subordinance events in Bengkulu but not in California; published reports suggest that the latter pattern is prominent worldwide. Study 3 mapped the semantic domain of shame using a synonym task; again, guilt was prominent in California, subordinance in Bengkulu. Because shame is overshadowed by guilt in individualistic cultures, and because these cultures downplay aversive emotions associated with subordinance, a fuller understanding of shame is best arrived at through the study of collectivistic cultures such as Bengkulu. After reviewing evolutionary theories on the origins and functions of shame, I evaluate these perspectives in light of facets of this emotion evident in Bengkulu and elsewhere. The available data are consistent with the proposition that shame evolved from a rank-related emotion and, while motivating prestige competition, cooperation, and conformity, nevertheless continues to play this role in contemporary humans.http://www.bec.ucla.edu/papers/Fessler_4-11-05.pdf

Mark Kleiman - Dominance hierarchies and public policies
2005-04-04 00:00
Mark Kleiman: UCLA Department of Public Policy1. Dominance hierarchies help resolve conflicts over resources with a minimum of actual combat by giving the higher-ranking individual priority. To some extent, then, the hierarchy ranking is going to reflect who would come out on top if there were actual combat.
2. In complicated human societies, the structure of the dominance hierarchy(ies) is partly a matter of deliberate choice, including deliberate choice through public policy. As Aristotle pointed out, a democratic regime doesn’t just mean that public decisions get made by the many rather than by a few or by one; it means greater social equality as well.
3. In designing social institutions relating to dominance, there are two big questions:
a. How steep the gradient should be.
b. What behaviors should lead to dominant status.
4. Being on top of the dominance hierarchy means more access to resources. That makes it desirable, and worth fighting for. And in fact individuals in all dominance-hierarchy-forming species do fight for dominance.
5. But if access to resources were all that counted, then resource-rich environments would reduce the intensity of dominance conflict. Is that true?
6. Being lower on the hierarchy in a resource-rich environment can mean more access to resources than being higher up in a resource-poor environment. (We all eat better, sleep more comfortably, and have better medical care than Louis XIV did.)
7. Economists normally assume that people care about the resources available to themselves and not where they stand in dominance hierarchies. That’s what makes the Pareto Principle seem plausible.
8. But some resources are naturally scarce; not everyone can have preferential access to mating opportunities, for example.
9. It turns out empirically that, holding resource access constant, position in hierarchy is an important contributor to health and other measures of well-being. (Whitehall studies.)
10. That makes evolutionary sense.
11. It also turns out empirically that, while cross-sectionally within a society wealth correlates with happiness, that doesn’t hold longitudinally as a society gets richer or cross-sectionally among societies, above a national income of something like 1/3 of that currently enjoyed in the U.S. (Hedonics literature, e.g., Easterlin, Kahnemann)
12. Ideally, dominant status should accompany pro-social behaviors. One advantage of market-driven societies is that people gain status by accumulating wealth rather than by accumulating the means of violence.
13. On the other hand, awarding dominance to money can lead to an unhealthy concentration on money-making. As Keynes said, in a poor society getting the smartest people to concentrate on making money is a good way to expand total resources available. But now that we’re rich enough so that the benefits of getting richer are limited, maybe we ought to start rewarding more attractive human traits than diligent and well-directed greed. If you value art and science, you ought to be thinking about how to arrange things so that producing art and science is a good way to acquire dominant status.
14. Awarding dominance to money also promotes Veblenesque conspicuous-consumption behavior, and commodity fetishism. Conspicuous consumption is largely signaling behavior: spending is a market signal for wealth, so the more closely dominance runs with wealth, the greater the incentive for conspicuous waste. Marketing means convincing people that it’s important to have whatever it is you’re trying to sell. Being inundated with marketing (other than Citigroup ads) should make people value “stuff” more relative to, e.g., leisure or culture or virtue or happiness.
15. Increasing scale through rising population, cheap communication, e-commerce, and globalization tends to increase income inequality, at least at the top of the scale, because the greater the size of the potential market the greater the rewards for outstanding performance. (Cook and Frank’s “winner-takes-all” effect.
16. Given how unhealthy, and how bad for your children, it is to be at the bottom of the pecking order, we need to ask whether, and how, that problem can be allieviated.
— Gentler status gradients
— Multiple hierarchies
17. That would be worth doing even at some cost in economic efficiency, narrowly considered. But social exclusion has big external costs, so relieving the problems at the bottom of the pecking order might turn out to have big benefits, even in strictly economic terms.
18. It would seem logical that a more equal income distribution would make money less important in awarding status. But is that true?
19. If money gets less important in awarding status, does the total steepness of the hierarchy gradient decrease, or is money just replaced by something else with the gradient held constant or even increased?
20. Norms of informality, whether Quaker or hippie, seem designed to reduce status gradients. Do they work?http://www.sciencedirect.com/science/article/B6V8F-3YGTSKK-T/2/964f8cb37c7ea0eb05ed82b7b18ae978

Kang Lee - Little Liars: Development of Verbal Deception in Different Social Contexts
2005-03-14 00:00
Kang Lee: UC San Diego Department of PsychologyIn this talk, I will present three sets of studies that examined childrenâ€™s lying: (a) to conceal their own transgression, (b) to be polite, and (c) to be modest. I will use the results of these studies to illustrate that (a) lying is a behavior that develops early and rapidly, (b) preschoolers are already capable of managing their nonverbal behaviors when lying, which makes their lies difficult to detect, and (3) cultural factors influence both childrenâ€™s moral understanding of lying and their actual behavior. However, there exists a complex relationship between childrenâ€™s moral understanding: One factor is whether both are consistently promoted and sanctioned in a culture. When they are not, there is no relationship between the two. When they are, there is a small to moderate correlation between the two.http://www.bec.ucla.edu/papers/Lee_3-14-05.pdf

Joanna Mountain - Deep common ancestry of African click-speaking populations
2005-03-07 00:00
Joanna Mountain: Stanford University Department of Anthropological SciencesIn the 1960’s linguist Joseph Greenberg classified all languages spoken primarily in Africa into four families. One of those families, Khoisan, includes not only the languages of the Khoe and San peoples of southern Africa, but also the languages of the Hadzabe and Sandawe peoples of Tanzania. Primary criteria for including languages in the Khoisan family were the presence of click-consonants and the absence of evidence of recent borrowing of such clicks. In 1998 we set out to compare the genetic variation of the Hadzabe with that of a San population of Namibia in order to better understand both the linguistic and population history of this broad region of Africa. Our analyses of mitochondrial DNA and Y chromosomal variation indicated deep genetic divergence between these click-speaking populations, with implications for the evolution of the click languages. More recently Sarah Tishkoff of the University of Maryland and I have teamed up to investigate how the Sandawe fit into the picture. Intriguingly, even the geographically proximate click-speaking populations, the Hadzabe and Sandawe, are relatively divergent in terms of genetic variation. Furthermore, the haplotypes of some Sandawe individuals indicate a deep but unique link with the San. The correspondence with the conclusions of linguist Bonny Sands is striking.http://www.bec.ucla.edu/papers/Mountain_3-7-05.pdf

Neil Tsutsui - Genetics and social organization of an invasive ant in its native and introduced ranges
2005-02-28 00:00
Neil Tsutsui: UC Irvine Department of Ecology and Evolutionary BiologyCultural evolution is driven in part by the strategies individuals employ to acquire behavior from others. These strategies themselves are partly products of natural selection, making the study of social learning an inherently Darwinian project. Formal models of the evolution of social learning suggest that reliance on social learning should increase with task difficulty and decrease with the probability of environmental change. These models also make predictions about how individuals integrate information from multiple peers. We present the results of micro-society experiments designed to evaluate these predictions. The first experiment measures baseline individual learning strategy in a two-armed bandit environment with variation in task difficulty and temporal fluctuation in the payoffs of the options. Our second experiment addresses how people in the same environment use minimal social information from a single peer. Our third experiment expands on the second by allowing access to the behavior of several other individuals, permitting frequency-dependent strategies like conformity. In each of these experiments, we vary task difficulty and environmental fluctuation. We present several candidate strategies and compute the expected payoffs to each in our experimental environment. We then fit to the data the different models of the use of social information, and identify the best-fitting model via model comparison techniques. We find substantial evidence of both conformist and non-conformist social learning and compare our results to theoretical expectations.http://www.bec.ucla.edu/papers/Tsutsui_2-28-05.pdf

Dwight Read - Where Does Culture Fit In?
2005-02-14 00:00
Dwight Read: UCLA Department of AnthropologyA long standing issue in human societies has been the relationship between culture and behavior. One extreme position views culture as arising primarily out of behavior structured by a variety of processes, ranging from external factors such as environmental conditions to internal factors such as behavioral consequences arising directly from interactions of individuals within groups. The other extreme sees behavior as a consequence of the roles and identities that individuals take on. Change in those roles and identities are seen as occurring over relatively long time scales, thereby giving primacy to viewing behavior as arising from the cultural context in which individuals are embedded. The sociologist James March has recently argued that neither position has successfully demonstrated the irrelevancy of the other position, but his argument leaves unanswered how these two positions might be integrated into a more encompassing view of the processes affecting and structuring human behavior, including the capacity of human systems for self-restructuring. I will address these two positions by considering two sharply contrasting hunting and gathering groups, the Netsilik Inuit of Hudson Bay in Canada the Tiwi on Melville and Bathurst Islands off of the NW coast of Australia.
I will use the Netsilik as an example amenable to the first position and argue that the Netsilik cultural framework of infant naming and sealing partners provided a cultural basis for implementing methods of resource procurement that were necessary for survival in their extreme, Arctic region. At the same time I will argue that the cultural framework is more complex than simply reflecting necessary patterns of behavior in that the cultural framework not only provides a cultural basis for implementing the required behaviors, but the cultural framework has its own dynamics and thereby adds another dimension that structured their particular behavioral means for coping with the environmental constraints to which they had to adapt.
The Tiwi, I argue, provide a stark contrast to the Netsilik and exemplify the way in which the cultural framework can have far reaching consequences for social organization and behavior that only makes sense by reference to the cultural system(s) in which the behavior is grounded, rather than by reference to behavior as the means to interact with their environment or as arising from the consequences of individual interaction, per se. In brief, the Tiwi had an extremely complex social system structured by a kinship framework that appears to bear little relevance to what was required to procure resources on Melville and Bathurst Islands.http://www.bec.ucla.edu/papers/Read_2-14-05_a.pdf

Richard McElreath - Applying evolutionary models to the laboratory study of social learning
2005-02-07 00:00
Richard McElreath: UC Davis Department of AnthropologyCultural evolution is driven in part by the strategies individuals employ to acquire behavior from others. These strategies themselves are partly products of natural selection, making the study of social learning an inherently Darwinian project. Formal models of the evolution of social learning suggest that reliance on social learning should increase with task difficulty and decrease with the probability of environmental change. These models also make predictions about how individuals integrate information from multiple peers. We present the results of micro-society experiments designed to evaluate these predictions. The first experiment measures baseline individual learning strategy in a two-armed bandit environment with variation in task difficulty and temporal fluctuation in the payoffs of the options. Our second experiment addresses how people in the same environment use minimal social information from a single peer. Our third experiment expands on the second by allowing access to the behavior of several other individuals, permitting frequency-dependent strategies like conformity. In each of these experiments, we vary task difficulty and environmental fluctuation. We present several candidate strategies and compute the expected payoffs to each in our experimental environment. We then fit to the data the different models of the use of social information, and identify the best-fitting model via model comparison techniques. We find substantial evidence of both conformist and non-conformist social learning and compare our results to theoretical expectations.http://www.bec.ucla.edu/papers/McElreath_2-7-05.pdf

Jon Haidt - Intuitive ethics: How a few evolved intuitions give rise to culturally variable virtues
2005-01-31 00:00
Jon Haidt: University of Virginia Department of PsychologyMorality has long been thought to come from outside â€“ from God, society, or parents â€“ into children, who are empty vessels. In contrast, an â€œexternalizationâ€ model is presented in which four cognitive/affective modules generate intuitions about social events. The modules respond to issues of harm/suffering, reciprocity/fairness, hierarchy/duty, and purity/piety. (This theory draws heavily on the works of A. Fiske and R. Shweder.) The modules were created by natural selection, but they co-evolved with cultural learning. Cultures create variable sets of virtues that are grounded in and constrained by the four modules. The case of the purity module is worked out in detail, including experimental demonstrations that flashes of irrelevant disgust (triggered by hypnosis, or by working at a dirty desk) make moral judgments more severe.http://www.bec.ucla.edu/papers/Haidt_1-31-05.pdf

David Reznick - The evolution of placentas in the Poeciliid fishes: An empirical study of macroevolution
2005-01-24 00:00
David Reznick: UC Riverside Department of BiologyAn unanswered question in biology is â€œhow do complex traits evolve?â€. This question endures as an area of controversy because of a paucity of empirical evidence and because the process unfolds on a time scale that is far longer than human experience. I am developing a model system for the evolution of complexity by studying the evolution of the placenta in the fish subfamily Poeciliinae. This group of fish offers a unique opportunity to study the evolution of complexity because placental adaptation exhibits: 1) dynamic variation: placentas appear to have evolved five or more times in the family, 2) serial variation: in several cases, closely related species exhibit either no placentas, intermediate stages, or highly developed placentas, and 3) quantitative variation: an objective criterion for pre- versus post-fertilization maternal provisioning exists which provides an index of placental performance. Furthermore, these fish are readily reared and bred in captivity, are easily studied in nature, and have an excellent prior history as subjects in laboratory and field studies. Evaluating the evolution of complexity demands integrated studies at different levels of biological organization. I envision the ongoing research as creating a template that will facilitate such work because it will define independent origins of placentas and groups of closely related species that either do not have a placenta or have a placenta in an intermediate stage of development. These sets of species represent the likely sequence of events associated with the evolution of the placenta and become the targets of further study.
I am my collaborators are using a combination of molecular and morphological systematics to define relationships within the subfamily and the relation of the subfamily to the remainder of its order. We are quantifying the life histories of these fish so that we can combine life history and phylogeny data, then apply statistical methods that will allow us to infer the patterns of evolution of life histories in the subfamily. We will also use these methods to develop hypotheses for how and why the placenta evolved. Finally, we are executing a series of laboratory experiments that test predictions and assumptions derived from recently developed theory for the evolution of placentas.http://www.bec.ucla.edu/papers/Reznick_1-24-05.pdf

Dan Blumstein - The evolution, function and meaning of alarm communication in marmots
2004-12-06 00:00
Dan Blumstein: UCLA Department of Organismic Biology, Ecology and Evolution Many prey species signal when they encounter a predator. For over a decade I’ve used anti-predator communication as a model for understanding the evolution of complex communication in general. I will summarize results, primarily focusing on my work with marmots–large, alpine ground squirrels found throughout the Northern hemisphere. I will talk about recent work on the evolution of alarm communication in rodents as well as in marmots, and the current adaptive utility of alarm communication. Surprisingly, it seems that alarm calls first evolved as a form of detection signalling primarily directed to predators. Calling has subsequently been exapted to have a conspecific alarm function. Much of my work has focused on the meaning of alarm calls. While marmots don’t seem to have functionally referential communicative abilities, they do encode risk in a variety of ways. Much recent work has focused on the somewhat paradoxical question of why calls might be individually specific. Evaluating caller reliability seems to be the key to selecting for the ability to distinguish among callers.http://www.bec.ucla.edu/papers/Blumstein_12-6-04.pdf

Michael Sockol - Investigating the Origins of Hominid Bipedalism
2004-11-29 00:00
Michael Sockol: UC Davis Department of Anthropology The origin of the human family, Hominidae, has been a primary focus of paleoanthropologists for more than a century. Indeed, the desire to understand our origins is ubiquitous in human society. Of continuing interest to anthropologists is the nature of the shift to bipedal locomotion in our earliest hominid ancestors. Though debate exists about whether bipedalism serves to define Hominidae, it is clear that becoming bipedal was the critical first step in the emergence of the human form, preceding all other major morphological adaptations. Yet, while the end result is apparent in the fossil record, the process by which bipedalism arose is unclear. Numerous hypotheses have been proposed for the shift to bipedal locomotion. Many have been discarded while others have withstood the test of time. One such hypothesis, commonly referred to as the â€œenergetics hypothesisâ€, posits an energy savings associated with bipedalism in an ecological context. I review the current state of our knowledge of the shift to bipedal locomotion in early hominids and give reasons for considering the energetics hypothesis as crucial to understanding that shift.

William Rice - Reproductive interactions between the sexes: arms-race or mutualistic coevolution?
2004-11-22 00:00
William Rice: UCSB Department of Ecology, Evolution & Marine BiologyThe empirical foundation for sexual conflict theory is the unequivocal data from many different taxa demonstrating that females are harmed while interacting with males. But the interpretation of this keystone evidence has been challenged because females may more than compensate the direct costs of interacting with males by the indirect benefits of obtaining higher quality genes for their offspring. A quantification of this trade-off is critical to resolve the controversy. Here I present results from 3 experiments that show that, at least in the D. melanogaster model system, indirect benefits do not off-set direct harm to females due to their interactions with males. I also present evidence, using hemiclonal analysis, that an ongoing arms race between the sexes can be directly measured in this model system.

Francis Steen - The role of consciousness in learning from simulations
2004-11-15 00:00
Francis Steen: UCLA Department of Communication StudiesI argued in Steen & Owens (2001) that play is a behavioral and cognitive simulation whose biological function is learning. In this presentation, I address the question of how such learning takes place, focusing on the role of consciousness. I present some preliminary data from an experiment on strategy-learning in a solitaire game, and a cognitive model of the large-scale architecture of the mind required to support learning from simulations.http://cogweb.ucla.edu/crp/Papers/Steen_Paradox.html

Fiona Cowie - Language Genes, Language Organs and Language Evolution
2004-11-08 00:00
Fiona Cowie: California Institute of Technology Division of the Humanities and Social SciencesThe recent identification of the so-called ‘grammar gene,’ FOXP2, as well as recent advances in our understanding of the numerous psychological mechanisms involved in language acquisition, raise a number of conceptual and empirical issues that are vital to our understanding of language evolution. In what sense, if any, can a gene like FOXP2 be called a ‘gene for language’? In what sense, if any, can a congeries of multi-functional psychological mechanisms be called a ‘language organ’? In light of our answers to these questions, how are we to conceive the role of biological evolution in the evolution of language?

Alan Grafen - Do animals really maximise their inclusive fitness?
2004-11-01 00:00
Alan Grafen: University of Oxford Department of ZoologyMost fieldworkers and empirical biologists studying whole organisms use as a working hypothesis that organisms have been designed by natural selection to maximise their inclusive fitness. They have used this approach to great effect since the work of Hamilton (1964) became widely known in the 1970s. On the other hand, population geneticists have mostly consistently denied that natural selection causes any quantity to be maximised, and have in general been critical of Hamilton’s work. It is an established part of the Modern Synthesis that the basis for natural selection must be found in population genetics models, which in mathematical terms are expressed in equations of motion. The modern way to represent design, used in economics though little in biology, is through optimisation programs. Recent unpublished work is outlined which, by making formal links between the mathematics of motion and optimisation programs, begins to provide a rigorous justification for the maximisation of inclusive fitness. Previous work relating to non-social behaviour can be found in the following references (available at http://users.ox.ac.uk/~grafen/):

Yaniv Hanoch - Emotions, boundedly rational agents and the fast and frugal perspective
2004-10-25 00:00
Yaniv Hanoch: UCLA School of Public Health, Department of Health ServicesHerbert Simon has warned us that an explanatory account of human rationality must identify the significance of emotions for choice behavior. Customarily emphasizing the cognitive dimensions of decision making, relatively few researchers have paid close attention to specifying the complex ways in which emotion may shape human thinking and decisions. Accordingly, this paper is an attempt to follow Simonâ€™s suggestion and specify how emotions can enter into the theory of bounded rationality. To accomplish our task, we capitalize on Rom HarrÃ©â€™s work on causal powers, from which we propose a strategy to study the significance of emotion in decision-making processes. In an attempt to elaborate on an explanation of behavior by mechanism, we discuss a version of bounded rationality recently put forward by Gigerenzer, Todd, and the ABC Research Group (Gigerenzer et al. 1999; Gigerenzer & Selten 2001), the so-called adaptive toolbox of fast and frugal heuristics. Coupled with insights from evolutionary psychology and neuroscience, this version of bounded rationality gives us a better grasp of the functional role of emotions within the human decision machinery.http://www.bec.ucla.edu/emotionalmechanismBEC.pdf

Andrew Shaner - Schizophrenia: What's Love Got To Do With It?
2004-10-18 00:00
Andrew Shaner: David Geffen UCLA School of MedicineSchizophrenia should not exist. It crushes sexual relationships and reproductive success and thus should have been eliminated long ago by selection. Yet it persists at a global prevalence far too high to be due to new mutations at a few loci. This has convinced scientists that many loci must be involved. But what evolutionary basis might there be for mutations at so many loci to produce the same disorder?
In a paper to be published in Schizophrenia Research, my coauthors and I propose an answer using one of the most recent and provocative developments in evolutionary theory: costly signaling theory and its application to sexually selected traits such as bright feathers and mating calls. According to costly signaling theory, only individuals with the best genes can grow the most attractive versions of sexually selected traits. Consequently, these traits serve as fitness indicators. Individuals who prefer mates displaying the most fully developed forms of these traits increase the fitness of their offspring.
Based on this theory, we propose that schizophrenia persists because it is the unattractive extreme of sexually selected fitness indicator — that it is analogous to a small, dull peacock’s tail. We suspect that the indicator trait itself-the human equivalent of a peacock’s tail — is the uniquely human capacity for verbal courtship (e.g., telling stories and jokes to potential mates) and the symptoms of schizophrenia are aberrant and unsuccessful versions of verbal courtship. This speculation helps illustrate our hypothesis, yet is unnecessary for our explanations and predictions. These depend only on a few general properties of sexually selected traits.
In this talk, I review sexual selection and fitness indicators, introduce our new model of schizophrenia, discuss its explanatory power, explain how it resolves the evolutionary paradox, discuss its implications for gene hunting, and identify some empirically testable predictions as directions for further research.http://bec.ucla.edu/papers/Shaner2004.pdf

Ted Bergstrom - On the Economics of Polygyny
2004-10-11 00:00
Ted Bergstrom: UCSB Department of EconomicsAbout 80% of all societies recorded by anthropologists are polygynous (men have many wives). Even our own society is less monogamous than claimed. This paper attempts to explain such mysteries as why bride prices and dowries are not “opposites”, why polygamous societies are usually characterized by positive bride prices and dowry is mainly confined to monogamous societies, why polyandry (women having multiple husbands) is rare, but not extinct, and why the more you have to pay for a wife the better you will treat her.http://www.bec.ucla.edu/polygyny3.pdf

Martie Haselton - Ovulatory Shifts in Women's Desires
2004-10-04 00:00
Martie Haselton: UCLA Department of Communication StudiesOvulatory cycle research reveals a hidden side of female desire. Near ovulation, women feel increased attraction to extra-pair mates, and they place a premium on “sexy” characteristics in men. Their primary mates respond with increased jealousy. Ovulatory shifts in women’s desires are expressed conditionally–for example, they are stronger in women mated to high investing but low attractiveness men. These findings suggest antagonistically coevolved strategies in men and women, and they provide support for the good genes hypothesis of multiple mating by women.

David Funder - The Personality Judgment Instinct
2004-06-07 00:00
David Funder: UC Riverside Dept. of PsychologyThe Realistic Accuracy Model (RAM) describes the four stage, social-behavioral process necessary for the achievement of accuracy in personality judgment. A judgmental target must emit (1) relevant information in a context where it is (2) available to the judge, who must then (3) detect and correctly (4) utilize this information. This model implies that accuracy is a difficult attainment, and yet useful levels of accuracy are routinely observed, which suggests there may be a sort of instinct for personality judgment, akin to the “language instinct,” that allows the cognitive system to go beyond the information given.http://www.bec.ucla.edu/papers/Funder_6-7-04.pdf

Laura Baker - Risk Factors for Antisocial Behavior: Genes and Environment
2004-05-24 00:00
Laura Baker: USC Dept. of PsychologyHuman aggression and antisocial behavior are known to be the product of both social and biological risk factors. What is not yet understood is how environment and genetic factors may mediate the interrelationships among these risk factors and antisocial outcomes. A study of twins and their families provides the ideal opportunity to answer the critical question in this regard: Do measured social and biological variables relate to antisocial development for genetic or environmental reasons? Our ability to develop effective and efficient interventions for antisocial behavior rests critically upon the answer to this question.
Preliminary results will be presented from the 1st wave of an ongoing longitudinal study of antisocial and aggressive behavior in 600 twin pairs (both male and female), aged 9-10 years old during an initial assessment. The study provides the first opportunity to investigate the environmental and genetic underpinnings of important social and biological risk factors for unlawful, antisocial, and aggressive behavior in boys and girls on the brink of adolescence. Social risk factors include aspects of the family environment, such as socio-economic status, emotional climate, cohesion, parental warmth and affection, parental supervision, discipline and control. Specific environmental factors for each twin are also studied, including individual relationships with each family member, as well as peer-group characteristics. Biological risk factors include psychophysiological indicators of arousal (both electrodermal and cardiovascular channels), electrocortical measures of brain activity (using both EEG and ERP measures) as well as neuropsychological and cognitive testing. Both the social and biological risk factors studied will be shown to distinguish between children exhibiting varying levels of aggressive and antisocial behavior. Biometrical analyses of twin similarity for ASB and a selected group of these risk factors will be presented.

Lynn Fairbanks - Adolescent Impulsivity and Adult Male Dominance in Vervet Monkeys
2004-05-17 00:00
Lynn Fairbanks: UCLA Neuropsychiatric InstituteAdolescence is characterized by behavioral and physiological changes that prepare individuals for the transition to adulthood. The purpose of this study was to evaluate the effects of behavioral, morphological, neurobiological and developmental characteristics of adolescent male vervets in predicting later dominance attainment. The results indicated that males that were high in impulsivity as adolescents and low in 5-HIAA prior to introduction were more likely to achieve stable alpha male status one year following introduction. These two factors, combined with body weight prior, resulted in correct prediction of rank attainment for 92% (33/36) of the males. Two other factors, maternal dominance rank and a measure of social anxiety from the Intruder Challenge test, were not related to adult dominance attainment in this sample. These results provide support for benefits of a high-risk, high-gain strategy by adolescent and young adult male vervets. They also demonstrated that adolescent impulsivity is age-limited. Males that achieved high rank moderated their behavior as adults, and no longer scored high in impulsivity relative to their age peers.

Shelly Gable - Approaching affiliation and avoiding rejection: A motivational perspective on the formation and maintenance of social bonds
2004-05-10 00:00
Shelly Gable: UCLA Dept. of PsychologySocial bonds are potent sources of both pleasure and pain; yet despite the precarious balance of interpersonal incentives and threats, across the life span people are tenaciously motivated to form and maintain strong and stable social bonds. Although myriad evidence supports the existence of a need for relationships, proportionately little work has investigated the regulatory processes involved in establishing, maintaining, and dissolving social bonds from a motivational or goal theory perspective. A critical dimension of motives and goals is their focus. Social motives and goals can be focused on the incentives and desired end-states of relational bondsâ€”approachâ€”or social motives and goals can be focused on the threats and undesired end-states of relational bondsâ€”avoidance. And, work on motives and goals has shown that the approach/avoidance distinction has important implications for behavior, affect, well-being, and health, but this research has not focused explicitly on social motives and goals. And, close relationships research has often targeted either the incentives (e.g., intimacy) or the threats (e.g., insecurity) associated with social bonds, but rarely has examined them in tandem. Given that interpersonal relationships present us with both threats and incentives, research on motives, goals, and the regulation of social behavior needs to simultaneously address the approach dimension and the avoidance dimensions of social behavior. In this talk I will present data from several studies in which we test aspects of approachâ€”avoidance model of social motivation in an effort to understand how humans weigh social incentives and threats and how approach and avoidance motivation influence attention, cognition, affect, and behavior in the context of social bonds.
