Conspicuous displays of consumption and benevolence might serve as “costly signals ” of desirable mate qualities. If so, they should vary strategically with manipulations of mating-related motives. The authors examined this possibility in 4 experiments. Inducing mating goals in men increased their willingness to spend on conspicuous luxuries but not on basic necessities. In women, mating goals boosted public—but not private—helping. Although mating motivation did not generally inspire helping in men, it did induce more helpfulness in contexts in which they could display heroism or dominance. Conversely, although mating motivation did not lead women to conspicuously consume, it did lead women to spend more publicly on helpful causes. Overall, romantic motives seem to produce highly strategic and sex-specific self-presentations best understood within a costly signaling framework. Key words: costly signaling, altruism, conspicuous consumption, mating goals, self-presentation We should often blush at our noblest deeds if the world were to see all their underlying motives.—Francois de La Rochefoucauld On Valentine’s Day 2003, America’s leading authority on philanthropy announced that real estate mogul Donald Trump had pledged $1 million to charity (Foundation Center, 2003). A few

commitment, conscientiousness, costly signaling theory, equilibrium selection, emotion, empathy, ethics, evolutionary psychology, fitness indicators, genetic correlations, good genes, good parents, good partners, human courtship, kin selection, kindness, individual differences, intelligence, mate choice, mental health, moral virtues, mutation load, mutual choice, person perception, personality, reciprocal altruism, sexual fidelity, sexual selection, social cognition, virtue ethics “Human good turns out to be the activity of the soul exhibiting excellence.” Aristotle (350 BC) Moral evolution theories have emphasized kinship, reciprocity, group selection, and equilibrium selection. Yet, moral virtues are also sexually attractive. Darwin suggested that sexual attractiveness may explain many aspects of human morality. This paper updates his argument by integrating recent research on mate choice, person perception, individual differences, costly signaling, and virtue ethics. Many human virtues may have evolved in both sexes through mutual mate choice to advertise good genetic quality, parenting abilities, and/or partner traits. Such virtues may include kindness, fidelity, magnanimity, and heroism, as well as quasi-moral traits like conscientiousness, agreeableness, mental health, and intelligence. This theory leads to many testable predictions about the phenotypic features, genetic bases, and social-cognitive responses to human moral virtues. A

Human behavior regarding medicine seems strange; assumptions and models that seem workable in other areas seem less so in medicine. Perhaps we need to rethink the basics. Toward this end, I have collected many puzzling stylized facts about behavior regarding medicine, and have sought a small number of simple assumptions which might together account for as many puzzles as possible. The puzzles I consider include a willingness to provide more medical than other assistance to associates, a desire to be seen as so providing, support for nation, firm, or family provided medical care, placebo benefits of medicine, a small average health value of additional medical spending relative to other health influences, more interest in public that private signals of medical quality, medical spending as an individual necessity but national luxury, a strong stress-mediated health status correlation, and support for regulating health behaviors of the low status. These phenomena seem widespread across time and cultures. I can explain these puzzles moderately well by assuming that humans evolved deep

Summary A collective action (CA), i.e., a group of individuals jointly producing a resource to be shared equally among themselves, is a common interaction in organizational contexts. Ancestral humans who were predisposed to cooperate in CAs would have risked being disadvantaged compared to free riders, but could have overcome this disadvantage through ‘greenbeard ’ reciprocity, that is, by assessing the extent to which co-interactants were also predisposed towards cooperation, and then cooperating to the extent that they expected co-interactants to reciprocate. Assessment of others ’ cooperativeness could have been based on the direct monitoring of, and on reputational information about, others ’ cooperativeness. This theory predicts that (1) CA participants should monitor accurately, and (2) perceived higher-cooperators should have better reputations. These predictions were supported in a study of real-life CAs carried out by a group of Shuar hunter-horticulturalists: (1) members accurately distinguished ‘intentional’ non-cooperators (who could have cooperated but chose not to) from ‘accidental ’ noncooperators (who were unable to cooperate), and their perceptions of co-member cooperativeness accurately reflected more objective measures of this cooperativeness; and (2) perceived intentional cooperators had better reputations than perceived intentional non-cooperators.

This chapter advances a new theory of altruism, competitive altruism, which might account for the uniquely moral altruistic tendency of humans. The need to form coalitions with non-kin for dealing with internal and external group threats created selective advantages for people with altruistic reputations. We present evidence from the anthropological, social psychological and nonhuman literatures, which by and large support competitive altruism theory. Finally, we discuss some implications of this theory for the establishment of reputation-based cooperation in modern human society.

This paper reports the results of the Ultimatum Game (UG), Dictator Game (DG) and Public Goods Game (PGG) played among the Tsimane, a group of forager-horticulturalists living in the Bolivian Amazon. Game results differ significantly from those commonly reported among modern, westernized populations. Without a long history of anonymous interactions, it is highly suspect whether the Tsimane or other traditional populations play economic games under assumptions of anonymity and one-shot exposure. Employing a behavioral ecology framework, I test predictions that differential market exposure, costs of giving, and experience with cooperation can help explain much of the variance in game outcomes. While these factors sometimes act as important predictors of game behavior, the most significant predictor is village membership. Implications for understanding the role of markets, frequent interaction with strangers, and payoffs to cooperation in daily life can help us better understand cross-cultural variation in pro-social behavior.

Human life histories, as compared to those of other primates and mammals, have at least four distinctive characteristics: an exceptionally long lifespan, an extended period of juvenile dependence, support of reproduction by older postreproductive individuals, and male support of reproduction through the provisioning of females and their offspring. Another distinctive feature of our species is a large brain, with its associated psychological attributes: increased capacities for learning, cognition, and insight. In this paper, we propose a theory that unites and organizes these observations and generates many theoretical and empirical predictions. We present some tests of those predictions and outline new predictions that can be tested in future research by comparative biologists, archeologists, paleontologists, biological anthropologists, demographers, geneticists, and cultural anthropologists. Hillard Kaplan is Professor at the University of New Mexico. His recent research and publications have focused on integration of life history theory in biology and human capital theory in economics, with specific emphases on fertility, parental investment, and aging in developed, developing, and traditional settings. He has also conducted fieldwork with native South Americans and southern Africans. Email:

*To whom correspondence should be addressed Recent empirical and theoretical work suggests that reputation was an important mediator of access to resources in ancestral human environments. Reputations were built and maintained by the collection, analysis, and dissemination of information about the actions and capabilities of group members—that is, by gossiping. Strategic gossiping would have been an excellent strategy for manipulating reputations and thereby competing effectively for resources and for cooperative relationships with group members who could best provide such resources. Coalitions (cliques) may have increased members ’ abilities to manipulate reputations by gossiping. Because, over evolutionary time, women may have experienced more within-group competition than men, and because female reputations may have been more vulnerable than male reputations to gossip, gossiping may have been a more important strategy for women than men. Consequently, women may have evolved specializations for gossiping alone and in coalitions. We develop and partially test this theory.

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Why do people purchase proenvironmental “green ” products? We argue that buying such products can be construed as altruistic, since green products often cost more and are of lower quality than their conventional counterparts, but green goods benefit the environment for everyone. Because biologists have observed that altruism might function as a “costly signal ” associated with status, we examined in 3 experiments how status motives influenced desire for green products. Activating status motives led people to choose green products over more luxurious nongreen products. Supporting the notion that altruism signals one’s willingness and ability to incur costs for others ’ benefit, status motives increased desire for green products when shopping in public (but not private) and when green products cost more (but not less) than nongreen products. Findings suggest that status competition can be used to promote proenvironmental behavior.