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.

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

SUMMARY—Amid ongoing public speculation about the reasons for sex differences in careers in science and mathematics, we present a consensus statement that is based on the best available scientific evidence. Sex differences in science and math achievement and ability are smaller for the mid-range of the abilities distribution than they are for those with the highest levels of achievement and ability. Males are more variable on most measures of quantitative and visuospatial ability, which necessarily results in more males at both high- and low-ability extremes; the reasons why males are often more variable remain elusive. Successful careers in math and science require many types of cognitive abilities. Females tend to excel in verbal abilities, with large differences between females and males found when assessments include writing

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.

# The Author(s) 2010. This article is published with open access at Springerlink.com Abstract Human coalitions frequently persist through multiple, overlapping membership generations, requiring new members to cooperate and coordinate with veteran members. Does the mind contain psychological adaptations for interacting within these intergenerational coalitions? In this paper, we examine whether the mind spontaneously treats newcomers as a motivationally privileged category. Newcomers—though capable of benefiting coalitions—may also impose considerable costs (e.g., they may free ride on other members, they may be poor at completing group tasks). In three experiments we show (1) that the mind categorizes coalition members by tenure, including newcomers; (2) that tenure categorization persists in the presence of orthogonal and salient social dimensions; and (3) that newcomers elicit a pattern of impressions consistent with their probable ancestral costs. These results provide preliminary evidence for a specialized component of human coalitional psychology: an evolved concept of newcomer.

ABSTRACT Personality psychology is the broadest of all psychological subdisciplines in that it seeks a conceptually integrated understanding of both human nature and important individual differences. Cultural differences pose a unique set of problems for any comprehensive theory of personality—how can they be reconciled with universals of human nature on the one hand and within-cultural variation on the other? Evolutionary psychology provides one set of conceptual tools by which this conceptual integration can be made. It requires jettisoning the false but still-pervasive dichotomy of culture versus biology, acknowledging a universal human nature, and recognizing that the human mind contains many complex psychological mechanisms that are selectively activated, depending on cultural contexts. Culture rests on a foundation of evolved psychological mechanisms and cannot be understood without those mechanisms. “The tabula of human nature was never rasa and is now being read” — W. D. Hamilton, 1997 Although cultural theorists define culture in somewhat different ways, many definitions share some core features. Culture is often used to refer to ideas, beliefs, representations, behavior patterns, practices, artifacts, and so forth that are transmitted socially across generations within a

Coalitional aggression evolved because it allowed participants in such coalitions to promote their fitness by gaining access to disputed reproduction enhancing resources that would otherwise be denied to them. Far fewer species manifest coalitional aggression than would be expected on the basis of the actual distribution of social conditions that would favor its evolution. The exploitation of such opportunities depends on the solution by individuals of highly complex and specialized information processing problems of cooperation and social exchange, and the difficulty of evolving cognitive mechanisms capable of solving such complex computational tasks may account for the phylogenetic rarity of such multi-individual coalitions. We propose that humans and a few other cognitively pre-adapted species have evolved specialized cognitive programs, that govern coalitional behavior, and constitute a distinctive coalitional psychology. An adaptive task analysis of what such algorithms need to accomplish, in the decisions regulating coalition formation, participation, cost and benefit allocation, allows the preliminary mapping of this coalitional psychology. Scrutinization of the adaptive features of coalitional aggression reveals some surprising characteristics, including that, under certain conditions, mortality rates do not negatively impact the fitness of males in the coalition, suggesting why warfare is so favored an activity, despite its risks to participating individuals ' welfare.

One of the strengths of scientific inquiry is that it can progress with any mixture of empiricism, intuition, and formal theory that suits the convenience of the investigator. Many sciences develop for a time as exercises in description and empirical generalization. Only later

*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.

The average man or woman had 2 surviving children. Such societies were also Darwinian. Some reproductively successful groups produced more than 2 surviving children, increasing their share of the population, while other groups produced less, so that their share declined. But unusually in England, this selection for men was based on economic success from at least 1250, not success in violence as in some other pre-industrial societies. The richest male testators left twice as many children as the poorest. Consequently the modern population of the English is largely descended from the economically successful of past generations. At the same time, from 1150 to 1800 in England there are clear signs of changes in average economic preferences towards more “capitalist ” attitudes. The highly capitalistic nature of English society by 1800 – individualism, low time preference rates, long work hours, high levels of human capital – may thus stem from the nature of the Darwinian struggle in a very stable agrarian society in the long run up to the Industrial Revolution. The triumph of capitalism in the modern world thus may lie as much in our genes as in ideology or rationality.