Fair play and its connection with social tolerance, reciprocity and the ethology of peace

The concept of peace, with its corollary of behaviours, strategies and social implications, is commonly believed as a uniquely human feature. Through a comparative approach, we show how social play in animals may have paved the way for the emergence of peace. By playing fairly, human and nonhuman animals learn to manage their social dynamics in a more relaxed and tolerant way that results in a more effective management of conflicts. We show that play promotes tolerance, cooperation, fairness and reciprocity, which are essential elements of the so-called positive peace. This kind of peace is reached through an evolving process in which individuals continually modify social relationships to attain peaceful coexistence. In conclusion, we assume that the concept of peace has deep biological roots that constitute the basis for more sophisticated cultural constructions.