Abstract

Evolutionarily-minded scholars working on the most puzzling aspects of human cooperation-one-shot, anonymous interactions among non-kin where reputational information is not available-can be roughly divided into two camps. In the first, researchers argue for the existence of evolved capacities for genuinely altruistic human cooperation, and in their models emphasize the role of intergroup competition and selection, as well as group norms and markers of membership that reduce intragroup variability. Researchers in the second camp explain cooperation in terms of individual-level decision-making facilitated by evolved cognitive mechanisms associated with well-established self- and kin-maximization models, as well as by ‘misfires’ that may result from these mechanisms interacting with novel environments. This essay argues that the manner in which culture provides information that de-anonymizes intragroup strangers suggests that neither evolved capacities for genuine altruism nor widespread misfires are necessary to account for anonymous, one-shot cooperation.