© RAI 2017 The emergence of cooperation in human societies has received ample academic attention from different disciplines, and is usually considered as an adaptive response to competition over scarce resources. In this article, the authors review the specific contribution that social anthropology has made to this field of research. They propose that social anthropology has contributed to this field through the description of systems that have regulated both cooperation and competition in traditional societies: (1) hunter-gatherer societies, where generalized reciprocity dominates; (2) prestige economies, which includes the exchange of valuables in specific spheres, primitive money, agonistic institutions in tribes; and last, (3) ‘moral economies’ in peasant communities, where cooperation and competition coexist but never at the cost of putting at risk the reproduction of the community itself or of some of its members. The three systems share the basic mechanism of reciprocity that allows for the maintenance of equality, as well as the very language for regulating competition in unequal prestige or moral economies. This pervasive presence of reciprocity as a moral norm would reveal its basic role in human evolution, and, likely, its co-evolution with ritual forms of social exchange.