Sarah Mathew – Is the Cultural Boundary also the Moral Boundary? 

Human ultra-sociality is enabled by a moral psychology that makes us adhere to and enforce prosocial norms, but what is the extent and limit of the moral psychology? Different hypotheses for how cooperation evolved make vastly different predictions about who our moral concerns should extend to: communities linked by gossip and social network ties; people who share cultural norms, values and beliefs; anyone with whom there are potential gains to be had from cooperation. I will provide data of cooperation and conflict among egalitarian, politically uncentralized pastoral communities in northern Kenya which show that people cooperate with those who share their cultural traits. These data suggest that selection among cultural groups is one of the key processes by which human cooperation and morality evolved. This observation can help understand what is the social scale and natural boundaries of our moral sphere.