Center for Behavior, Evolution, and Culture

David Reznick - The evolution of placentas in the Poeciliid fishes: An empirical study of macroevolution
2005-01-24 00:00 (America/Los_Angeles)
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.

Michael Gurven - Determinants of Time Allocation Across the Lifespan
2004-05-03 00:00
Michael Gurven: UCSB AnthropologyThis paper lays the groundwork for a theory of time allocation across the life course. It first develops a parametric model of rates of return on time allocated to productive activities as a function of age. The model is based on the idea that strength and skill vary as a function of age, and that return rates for different activities vary as a function of the combination of strength and skills involved in performing those tasks. The model is then extended to explain time allocation to different activities through the life course from childhood to old age. In addition to age effects on efficiency or productivity, the model includes danger and mortality risks, future benefits of learning, relative efficiencies of different family members and joint execution of tasks, as inputs into time allocation decisions. We then apply the model to traditional human subsistence patterns. The model predicts that young children would engage most heavily in low strength/low skill activities, middle-aged adults in high strength/high skill activities, and older adults in low strength/high skill activities. Data on time allocation and productivity among Machiguenga and Piro forager-horticulturalists of southeastern Peru are used to evaluate the model.

Christine Harris - Did Men and Women Evolve Different Jealousy Mechanisms?
2004-04-26 00:00
Christine Harris: UC San Diego Dept. of PsychologyThe specific innate modular theory of jealousy (JSIM) hypothesizes that men are innately prone to upset over a mateâ€™s sexual infidelity and women, over a mateâ€™s emotional infidelity. This view claims that natural selection has shaped sexual jealousy as a mechanism to prevent cuckoldry and emotional jealousy as a mechanism to prevent resource loss. Three lines of evidence have been offered as support: 1) psychophysiological reactions when imagining the two forms of infidelity, 2) responses to hypothetical scenarios, and 3) rates of domestic violence and morbid jealousy. This talk will re-examine each line of work and present evidence that questions the extent to which there are robust sex differences. An alternative theory of jealousy will be discussed which proposes a more domain general mechanism that may show little sexual dimorphism.http://www.bec.ucla.edu/papers/Harris_4-26-04.pdf

Stephen Stich - Why Moral Philosophers Need LOTS of Help from Psychologists, Anthropologists and Other Social Scientists
2004-04-19 00:00
Stephen Stich: Rutgers Dept. of PhilosophyThe talk has three parts:
In Part I, I will sketch a hotly debated question in moral philosophy. Roughly stated, the issue in dispute is whether moral disagreement is fundamental or superficial; disagreement is fundamental if it would persist even under â€œidealizedâ€ circumstances in which the parties to the dispute are fully rational, impartial, and agreed on all non-moral issues. Iâ€™ll then explain why moral many moral philosophers think the answer is of enormous importance.
In Part II, Iâ€™ll review two empirical studies that suggest moral disagreement is indeed fundamental. One study, rarely cited by social scientists, is Richard Brandtâ€™s philosophically motivated moral ethnography of the Hopi. The other is drawn from the work of Richard Nisbett and his colleagues on cultures of honor. These studies are hardly conclusive, however, and even if issues of interpretation are put to one side, those who do not believe that moral disagreement is fundamental might argue that the examples of moral disagreement on which they focus are outliers, and that in general moral views will converge under idealized circumstances. To address these concerns, we need an empirically supported theory of the psychological mechanisms underlying the acquisition & utilization of moral norms and of how those mechanisms might have evolved.
In Part III, I will provide an overview of a collaborative project aimed at developing an empirical theory of the psychology & evolution of moral norms. I will focus on two crucial issues that the theory must address:
â€¢ What sort of psychological mechanisms subserve the acquisition and implementation of norms?
â€¢ What constraints (if any) are there on the sorts of norms that can be acquired?
Though the existing empirical literature provides some very important clues, there are many crucial questions for which, as far as we have been able to discover, there is little or no relevant data available. My goal, in this part of the talk, is to provide a framework which makes clear what we need to know about the psychological mechanisms subserving moral norms. My hope is that some people in the audience will know of relevant findings that have escaped our notice, or (better still) that they can be tempted to design new studies that will help answer or reconfigure some of the most important and most venerable questions in moral theory.

Nancy K. Dess - Violence and Its Antidotes: Promises and Pitfalls of Evolutionarily Aware Policy Development
2004-04-12 00:00
Nancy K. Dess: Occidental CollegeGlimpses at our primate relatives and diverse human cultures provide prima facie evidence that as a species, we are capable of far more benevolent, just, and healthful living than exists in many places. Illuminating human nature through evolutionary reasoning has great potential to make public policy more effective and more humane. To fulfill this promise, historical and political realities that constrain or are conducive to evolutionary reasoning must be appraised. In addition, five unhelpful habits must be broken: analysis by false dichotomy; anthropodenial; perpetuation of aggression myths; oversimplification; and wishful thinking. Understanding the kind of animal we are may be as helpful to overcoming these obstacles as it will be to the formulation of good policy.

Lynn Stout - Other-Regarding Behavior and the Law
2004-04-05 00:00
Lynn Stout: UCLA School of LawLegal scholars have become keenly interested in behavioral approaches to lawthat recognize that real people do not always behave in a selfishly rational fashion: numerous recent papers examine how human choice can be distorted by endowment effects, anchoring effects, availability biases, and other cognitive deficiencies. There is a curious imbalance to this “behavioral law and economics” literature, however. Contemporary critiques of the selfish rationality model of human behavior tend to focus far more on the
second modifier – the assumption of rationality – than on first – the assumption of self interest.
This article reverses that emphasis. It argues that the human tendency to act in an other-regarding fashion (to sacrifice in order to help or harm others) is far more pervasive and important than generally recognized. In support of this claim, it reviews the extensive empirical evidence that has been accumulated over the past five decades on human behavior in experiments known as social dilemma games, ultimatum games, and dictator games. These experiments have consistently found that under certain circumstances, subjects routinely behave as if they care about costs and benefits to others. In the parlance of economics, they predictably “reveal”
other-regarding preferences. Moreover, this other-regarding behavior seems driven primarily by social context – subjects’ perceptions of what others believe, what others expect, and how others are likely to behave.
These findings are of importance not only to our understanding of individual behavior, but also to our understanding of a wide variety of social institutions, including the social institution known as law. To illustrate, this Article offers a simple model of other-regarding behavior derived from the experimental evidence. It then explores how the model sheds light on three basic areas of legal doctrine: tort, contract, and criminal law. As will be seen, incorporating other-regarding behavior into the analysis offers to explain a number of puzzles in these three areas that cannot be resolved by using the homo economicus model of selfish rationality. It also promotes a better appreciation of the essential role “conscience” may play in ensuring a functioning legal system, as well as the myriad, subtle, and sometimes counterintuitive ways in which state and private actors employ law to change behavior.

Alan Dixson - Sperm competition, mammalian reproduction, and human evolution
2004-03-15 00:00
Alan Dixson: Center for Reproduction of Endangered Species, Zoological Society of San DiegoThis talk focuses upon the structure and functions of the reproductive organs of mammals, as viewed from the perspective of sexual selection and sperm competition. The living collections of the Zoological Society of San Diego contain many rare and unusual species; valuable anatomical material becomes available whenever necropsies are performed. Comparative studies have allowed us to demonstrate effects of sexual selection upon sperm morphology, structure of the vas deferens, accessory sexual glands, and oviductal morphology in a variety of mammals. Inclusion of measurements of the human reproductive system in these studies has also provided some useful insights into the evolution of human sexuality.

Greg Bryant - Social and linguistic functions of prosodic cues in speech: an evolutionary approach
2004-03-08 00:00
Greg Bryant: UCSC Dept. of PsychologyDuring speech communication, conversationalists produce and understand many simultaneous pieces of information through prosodic features of the voice (i.e., pitch, loudness, and duration properties). Prosodic variations provide cues to lexical and grammatical units (linguistic prosody), as well as emotional and intentional information (affective prosody). But prosody may also be used by conversationalists to signal social information not necessarily linked to the meaning of the words used. In this talk I will present various research examining prosody production and perception in both linguistic and social contexts. I will then discuss related ideas concerning linguistic and affective prosodic distinctions, functional dissociations in pitch production including potential laryngeal specializations, and evidence for pitch perception differences between tone and non-tone language speakers. I will argue that prosodic communication systems are functionally organized and future research should examine correspondences between production systems and perceptual response biases.

Jim Sidanius - Individual and Institutional Congruence in the Reproduction of Group-based Social Hierarchy: A Social Dominance Perspective
2004-03-01 00:00
Jim Sidanius: UCLA Dept. of PsychologyBased upon ideas borrowed from classical elitism theory, social identity theory and evolutionary psychology, social dominance theory basically assumes that human social systems are predisposed to organize themselves as group-based social hierarchies. Given this assumption, social dominance theory then attempts to identity the multi-leveled processes that are responsible for the creation and maintenance of these hierarchies. Using social dominance theory as the guiding framework, in this talk I will discuss the manner in which the congruency between the hierarchical characteristics of social roles and the behavioral predispositions of people occupying those social roles are one set of processes contributing to the maintenance of group-based social hierarchy. Beginning with Holland (1959, 1966), numerous researchers have documented the fact that peopleâ€™s work-related values tend to match the values of their work environments. Researchers have also found, as we might expect, that this value match yields superior job performance and greater employee satisfaction. Social dominance theory has proposed an important expansion of this research: peopleâ€™s sociopolitical attitudes (e.g., anti-egalitarianism) should also be compatible, or congruent, with their institutional environments (e.g., schools, workplaces) and a growing body of research supports this claim. Specifically, recent research has shown that hierarchy-enhancing (HE) organizations (e.g., police forces) tend to be occupied by those with anti-egalitarian beliefs, while hierarchy-attenuating organizations (e.g., civil liberties organizations) tend to be occupied by those with relatively democratic beliefs. This research has also provided evidence for five (non-mutually exclusive) processes underlying this person/institution congruence: self-selection, institutional-selection, institutional socialization, differential reward, and differential attrition. Finally, targets of theoretical expansion will be discussed.

Rob Boyd - The Evolution of Contingent Cooperation
2004-02-23 00:00
Rob Boyd: UCLA Dept. of Anthropology

Aimee Plourde - The Evolution of Prestige Good Economies and the Origins of Sociopolitical Complexity
2004-02-09 00:00
Aimee Plourde: UCLA Dept. of AnthropologyThe emergence of social ranking and political hierarchy in human society constituted a fundamental departure from the small, egalitarian group structure thought to characterize society for most of our speciesâ€™ history. Explaining the origins of social ranking is thus key to understanding the underlying structures of modern human societies, and the evolutionary processes that have generated them. Archaeologists have argued that the emergence of an economy of prestige goods in prehistory provided a critical means for leaders in chiefdom-level societies to attract followers and establish hierarchical relations with elites in neighboring polities. However, these arguments fail to explain the initial attraction of prestige goods themselves. Here I present a model for the evolution of psychological mechanisms that value prestige goods, and outline the evolving role of prestige goods in the negotiation of hierarchy at increasing levels of political ranking. This model is assessed against archaeological excavation and survey data collected in the northern Lake Titicaca Basin of highland Peru. The data demonstrate that strong correlations exist between increasing polity size and political hierarchy on the one hand and increasingly direct control of the trade routes used to procure prestige items on the other.

Chris Boehm - Two Anthropological Models for Understanding Global Conflict Resolution
2004-02-02 00:00
Chris Boehm: USC Dept. of AnthropologyChimpanzees and human hunter-gatherers are taken as models which help to explain our troubled world of nations, which in many ways is like a chimpanzee community with dominant alpha nations that throw their weight around—but in others is like a hunter-gatherer band, in which the group sees to it that no one individual is permitted to be too “alpha.” In the latter sense, the United Nations is set up politically so that no single nation can dominate it because of the veto, and the resultant world of nations looks nothing like a single nation, which has sufficient coercive force at the political center to prevent most internecine conflict. Turning to the chimpanzee model again, there, too, coercive force is used within the society to control conflict, with alpha males displaying at combatants and separating them until they have cooled off. Distinctively, the alpha male mediation role is an even-handed one, even if the combatants are respectively allies and enemies of the alpha. Practical lessons to be learned come in the form of insights into problems and possibilities for creating a more effective world government, and in informing the world’s superpowers that conflict resolution, to be effective, should be even-handed. The Israeli-Palestinian case is taken briefly as an example.http://www.bec.ucla.edu/papers/Boehm_1-12-04.rtf

Jerome Siegel - The Phylogeny of Mammalian Sleep
2004-01-26 00:00
Jerome Siegel: UCLA Dept. of PsychiatrySleep amounts vary by more than an order of magnitude across mammalian species. Either the amount of time spent sleeping has no relation to underlying function, which would distinguish sleep from many other homeostatically regulated processes, or sleep need varies considerably across species.
Prior data and new data on primitive mammals and cetaceans indicate a strong negative correlation between total sleep time and weight. Because metabolic rate is strongly and negatively correlated with body mass, this is also a positive correlation between metabolic rate and sleep time. Some evidence suggests that brain regions with high metabolic rate have higher levels of sleep deprivation induced damage. We hypothesized that non REM sleep serves to repair damage caused by oxidative stress (Eiland et al., 2002; Ramanathan et al., 2002).
REM sleep and nonREM sleep amounts are positively correlated. One explanation for this is that REM serves to stimulate the brain to prepare for waking after a period of nonREM (Ephron, Carrington, 1966; Snyder, 1966; Vertes, 1986).
However, much of the variation in REM amounts is independent of nonREM duration. Animals born in a relatively immature state, have more REM early in development (Jouvet-Mounier, 1970). One may hypothesize that REM facilitates development. A major mystery is why immaturity at birth is correlated with REM time in adulthood.
Cetaceans show unihemispheric sleep, with both hemispheres never being in deep sleep at the same time. Fur seals show both unihemispheric sleep and bihemispheric sleep and can switch between these two modes. Unihemispheric sleep appears to largely do away with sleep rebounds after deprivation of bilateral sleep. Unihemispheric sleep is linked to low or absent REM sleep. Understanding the mechanisms and functional relations underlying these unusual sleep adaptations of marine mammals can offer a major insight into the function and mechanisms of sleep.

Gary Marcus - Language in the era of the Genome
2004-01-12 00:00
Gary Marcus: NYU Dept. of PsychologyTwo of the most central questions in understanding the nature of the uniquely human talent for language are the extent to which the underlying neural machinery is “innate” (or “built-in”), and the extent to which that machinery is specialized for language as opposed to other cognitive functions. In this talk, I show how recent research in genetics and developmental neuroscience suggests new ways of thinking about these questions.

Patricia Churchland - What Happens to Free Will if the Brain is a Causal Machine?
2003-12-01 00:00
Patricia Churchland: UCSD Dept. of PhilosophyAlthough questions concerning the nature of free choice have long been at the center of philosophical reflection, new discoveries, especially from neuropharmacology and neuropsychology, have lent them a special and very practical urgency. In the courts, in the education of children, and in general in daily life, we assume that some decisions are freely made and that agents should be held accountable for those decisions. On the other hand, there is pressure to expand of the range of allowable excuses from responsibility, as we begin to understand the role of certain neuropathologies in aberrant behavior. These developments take place against the public policy debate concerning the right balance between considerations of public safety, justice, fairness, and individual freedom. From the perspective of neurophilosophy, I shall address some of the broad questions in this arena, including the evolutionary basis for cooperative behavior, the neurobiology of the difference between being in control and being out of control, and the role of emotions in biasing moral choice.

Olav Sorenson - Social networks and exchange: Self-confirming dynamics in Hollywood
2003-11-24 00:00
Olav Sorenson: UCLA Anderson School of ManagementStudies have consistently found that social structure influences who transacts with whom, and that actors appear to benefit when exchange occurs embedded within these relations rather than in an unstructured market. Explanations for these results frequently point to their effectiveness in solving problems inherent in the trade of certain products and services, focusing on the ability of these social networks to provide access to private information regarding the quality of the goods or to allow participants to enforce the terms of the exchange agreement. In investigating these dynamics in the interaction between movie producers and distributors, this paper, however, suggests that a type of self-confirming prophecy can also produce such effects: One party frequently offers better terms of trade in transactions embedded within existing social relations, thereby contributing to the apparent benefits of such exchange patterns. In the motion picture industry, not only do distributors show a preference for carrying films involving key personnel with whom they have prior relations, but also they tend to favor these films when making decisions regarding their release â€“ in determining opening dates and the amount of resources devoted to marketing. Empirical estimates of the performance of movies in the U.S. box office reveal that â€“ when models fail to account for these key decisions â€“ distributors appear to benefit from carrying movies affiliated with known parties, suggesting that they have private information regarding the quality of the talent involved. After controlling for marketing effort and seasonality, however, these effects disappear, indicating that, rather than arbitraging price-quality inconsistencies, distributors produce these effects through their own efforts.http://www.bec.ucla.edu/papers/Sorenson_11-24-03.pdf
