Abstract

This article focuses on the explanations of human cooperation that dominate the fields of psychology, philosophy, economics and other social sciences. It argues that these accounts all frame cooperation in egoistic terms and thus cannot solve the evolutionary puzzle of strong reciprocity, defined as a propensity to cooperate with others similarly disposed and to punish others who violate norms, even at a personal cost and without any prospect of present or future rewards. This article shows that strong reciprocity accounts for the uniquely high levels of human cooperation and is best explained by referring to the important role of culture in natural selection. In the end, it aims to analyze the implications of these insights for the interdisciplinary aim of understanding the sources of cooperation.