We propose that the crucial difference between human cognition and that of other species is the ability to participate with others in collaborative activities with shared goals and intentions: shared intentionality. Participation in such activities requires not only especially powerful forms of intention reading and cultural learning, but also a unique motivation to share psychological states with others and unique forms of cognitive representation for doing so. The result of participating in these activities is species-unique forms of cultural cognition and (...) evolution, enabling everything from the creation and use of linguistic symbols to the construction of social norms and individual beliefs to the establishment of social institutions. In support of this proposal we argue and present evidence that great apes understand the basics of intentional action, but they still do not participate in activities involving joint intentions and attention. Human children's skills of shared intentionality develop gradually during the first 14 months of life as two ontogenetic pathways intertwine: the general ape line of understanding others as animate, goal-directed, and intentional agents; and a species-unique motivation to share emotions, experience, and activities with other persons. The developmental outcome is children's ability to construct dialogic cognitive representations, which enable them to participate in earnest in the collectivity that is human cognition. Key Words: collaboration; cooperation; cultural learning; culture; evolutionary psychology; intentions; shared intentionality; social cognition; social learning; theory of mind; joint attention. (shrink)

In small-scale societies, punishment of adults is infrequent and employed when the anticipated cost-to-benefit ratio is low, such as when punishment is collectively justified and administered. In addition, benefits may exceed costs when punishers have relatively greater physical and social capital and gain more from cooperation. We provide examples from the Tsimane horticulturalists of Bolivia to support our claims.

Fighting ability, although recognized as fundamental to intrasexual competition in many nonhuman species, has received little attention as an explanatory variable in the social sciences. Multiple lines of evidence from archaeology, criminology, anthropology, physiology, and psychology suggest that fighting ability was a crucial aspect of intrasexual competition for ancestral human males, and this has contributed to the evolution of numerous physical and psychological sex differences. Because fighting ability was relevant to many domains of interaction, male psychology should have evolved such (...) that a man’s attitudes and behavioral responses are calibrated according to his formidability. Data are reviewed showing that better fighters feel entitled to better outcomes, set lower thresholds for anger/aggression, have self-favoring political attitudes, and believe more in the utility of warfare. New data are presented showing that among Hollywood actors, those selected for their physical strength (i.e., action stars) are more likely to believe in the utility of warfare. (shrink)

Reciprocity theory (RT) and costly signaling theory (CST) provide different explanations for the high status of pro-community altruists: RT proposes that altruists are positively and negatively sanctioned by others, whereas CST proposes that altruists are attractive to others. Only RT, however, is beset by first- and higher-order free rider problems, which must be solved in order for RT to explain status allocations. In this paper, several solutions to RT’s free rider problems are proposed, and data about status allocations to Ecuadorian (...) Shuar pro-community altruists are analyzed in light of RT and CST. These data confirm that perceived pro-community altruists are indeed high status and suggest that (1) community residents skillfully monitor the altruism of coresidents, (2) residents who engage in opportunities to broadcast desirable qualities are high status only to the extent that they are considered altruistic, and (3) individuals who sanction coresidents based on coresidents’ contributions to the community are themselves relatively high status. To a greater extent than CST, RT straightforwardly predicts all of these results. (shrink)