Abstract not found

Abstract not found

Present conditions and selection pressures are irrelevant to the present design of orga-nisms and do not explain how or why organisms behave adaptively, when they do. To whatever non-chance extent organisms are behaving adaptively, it is 1) because of the operation of underlying adaptations whose present design is the product of selection in the past, and 2) because present conditions resemble past conditions in those specific ways made developmentally and functionally important by the design of those adap-tations. All adaptations evolved in response to the repeating elements of past environ-ments, and their structure reflects in detail the recurrent structure of ancestral envi-ronments. Even planning mechanisms (such as “consciousness”), which supposedly deal with novel situations, depend on ancestrally shaped categorization processes and are therefore not free of the past. In fact, the categorization of each new situation into evolutionarily repeating classes involves another kind of adaptation, the emotions, which match specialized modes of organismic operation to evolutionarily recurrent situations. The detailed statistical structure of these iterated systems of events is re-flected in the detailed structure of the algorithms that govern emotional state. For this

INTRODUCTION Young disciplines often experience moments of doubt: "Are we doing the right thing?" or "Is this approach viable?" [1]. Nowhere is this better exemplified than in the study of computer vision [2]. While progress has been made, the goal of general vision, on the order of human visual perception, remains elusive. Recently, this has led * Please address all correspondence to Michael J. Tarr, P.O. Box 208205, New Haven, CT 06520-8205, E-mail address: tarr@cs.yale.edu to the suggestion that the entire endeavor is flawed, that we should discard the dominant paradigm, and that it should be replaced with a new, more practical alternative. While this position may not qualify as a "paradigm shift" [3], it certainly advocates a substantial change in direction. To justify this radical deviation, proponents of the new, so-called purposive approach muster three lines of support: first, that machines fall far short of the visual capabilities of humans; second, that current com

A reconceptualization of stigma is presented that changes the emphasis from the devaluation of an individual's identity to the process by which individuals who satisfy certain criteria come to be excluded from various kinds of social interactions. The authors propose that phenomena currently placed under the general rubric of stigma involve a set of distinct psychological systems designed by natural selection to solve specific problems associated with sociality. In particular, the authors suggest that human beings possess cognitive adaptations designed to cause them to avoid poor social exchange partners, join cooperative groups (for purposes of between-group competition and exploitation), and avoid contact with those who are differentially likely to carry communicable pathogens. The evolutionary view contributes to the current conceptualization of stigma by providing an account of the ultimate function of Stigmatization and helping to explain its consensual nature.

The study of adaptive behavior, including learning, usually centers on the effects of natural selection for individual survival. But because reproduction is evolutionarily more important than survival, sexual selection through mate choice (Darwin, 1871), can also have profound consequences on the evolution of creatures' bodies and behaviors. This paper shows through simulation models how one type of learning, parental imprinting, can evolve purely through sexual selection, to help in selecting appropriate mates and in tracking changes in the phenotypic makeup of the population across generations. At moderate mutation rates, when populationtracking becomes an important but still soluble problem, imprinting proves more useful and evolves more quickly than at low or high mutation rates. We also show that parental imprinting can facilitate the formation of new species. In reviewing the biological literature on imprinting, we note that these results confirm some previous s...

Memory evolved to supply useful, timely information to the organism’s decision-making systems. Therefore, decision rules, multiple memory systems, and the search engines that link them should have coevolved to mesh in a coadapted, functionally interlocking way. This adaptationist perspective suggested the scope hypothesis: When a generalization is retrieved from semantic memory, episodic memories that are inconsistent with it should be retrieved in tandem to place boundary conditions on the scope of the generalization. Using a priming paradigm and a decision task involving person memory, the authors tested and confirmed this hypothesis. The results support the view that priming is an evolved adaptation. They further show that dissociations between memory systems are not—and should not be—absolute: Independence exists for some tasks but not others. Memory is a gift of nature, the ability of living organisms to retain and to utilize acquired information or knowledge.... Owners of biological memory systems are capable of behaving more appropriately at a later time because of their experiences at an earlier time, a feat not possible for organisms without memory. (Tulving, 1995a, p. 751) If there is one proposition on which all psychologists seem to

Those who contribute to a public good sometimes experience punitive sentiments toward others. But is the system that produces these sentiments an adaptation and, if so, which collective action problem was it designed to solve? Prior results from experimental economics show that acts of free riding are sometimes punished; that punishment deters free-riding; and that the risk or actuality of punishment recruits higher levels of cooperation in a joint effort. This suggests that one function of punitive sentiments could be to recruit labor for collective actions. However, adaptations designed to cause participation in collective actions could not have evolved unless there were some mechanism that protected those who participated from having lower fitness than non-participating free riders. Therefore, a second possible function of punishment could be to eliminate or reverse fitness differentials that favor free rider designs over participant designs. To map the computational structure of this motivational adaptation (and hence identify its specific function) requires data that relate an individual's circumstances to his or her desire to punish. Herein we report such data. The results indicate that the computational system that regulates one's level of punitive sentiment in collective action contexts is functionally specialized for removing the fitness advantage enjoyed by free riders, rather than for labor recruitment or other functions. Results also support the hypothesis that a separate pro-reward motivational system exists that appears designed to handle the problem of labor recruitment. Rational choice counterexplanations for punitive sentiments were considered, but eliminated on the basis of the evidence.

Evolution brought brains and minds into a world initially devoid of inteUlgent life. The evolutionary process designed the neural machinery that generates in-tehgent behavior, and important insights into how this machinery works can be gained by understanding how evolution constructs organisms. This is the ratio-nale that underlies research in evolutionary psychology. Evolutionary psychology was founded on interloclang contributions from evolutionary biology, cognitive science, psychology, anthropology, and neuro-science. It reflects an attempt to think through, from first principles, how cur-rent knowledge from these various fields can be integrated into a single, consistent, sciennfic framework for the study of the mind and brain (Cosmides

If a person doesn’t give something to me, I won’t give anything to that person. If I’m sitting eating, and someone like that comes by, I say, “Uhn, uhn. I’m not going to give any of this to you. When you have food, the things you do with it make me unhappy. If you even once in a while gave me something nice, I would surely give some of this to you.” Nisa from Nisa: The Life and Words of a!Kung Woman, Shostak, 1981, p. 89 Instead of keeping things, [!Kung] use them as gifts to express generosity and friendly intent, and to put people under obligation to make return tokens of friendship....In reciprocating, one does not give the same object back again but something of comparable value. Eland fat is a very highly valued gift...Toma said that when he had eland fat to give, he took shrewd note of certain objects he might like to have and gave their owners especially generous gifts of fat. Marshall, 1976, pp. 366–369