The Origin of Morality: From Behavioral Synchronization to Moral Norm Internalization

Abstract

The origin of human morality has always been a myth that draws the interest of research. Not until the flourish of the comparative approach to studying nonhuman social animals and infants did our understanding of morality start to develop. By reviewing the studies employed in this approach, the present review presents the first comprehensive synthesis of the evolved infrastructures that allow the acquisition and internalization of moral norms, with an expositional novelty that pictures the continuum of the origin of morality. By making phylogenetic and ontogenetic comparisons, the Nature-versus-Nurture debate surrounding morality is resolved: culturalization scaffolds the internalization of moral norms; while the evolutionary adaptations for prosociality and cooperation provide the biological basis that makes this internalization process possible. Hence, on the one hand, humans are not unique in possessing the evolved mechanisms that facilitate cooperation. On the other hand, however, humans excel other social animals in sharing and reading intention, seeking fairness, and creating and maintaining moral norms. Together, the reviewed evidence in the field of evolutionary psychology supports that morality is indeed a collection of both biological and cultural adaptations that facilitate cooperation and solve the problems occurred when cooperating.