When play is a strategy game : an overview in adult primates

A strategic game can be defined as a game in which players’ autonomous decision-making skills have a high significance in determining the outcome. Although the definition is clearly designed for humans, it can also apply to some kinds of animal play, at least under some peculiar circumstances. Different from immature play, which has its main role in developing physical, cognitive and social skills, adult play is strategically employed to reach different goals depending on the social and environmental conditions in which the player acts. Playing with unrelated infants represents a social bridge which adults can use to broaden and strengthen their social networks. Cross-species comparison of the genus Macaca, characterized by different degree of tolerance, shows that the bridge strategy is particularly effective in tolerant species in which the social canalization of infants by the mothers is less severe and infants are allowed to interact playfully with other adults. Play involving only adults opens further scenarios regarding the potential roles of this versatile behaviour. Adult-adult play in primates is far more pervasive than previously thought and it seems to be a response to an immediate or delayed necessity which lies outside the play session itself. Adult play in lemurs and bonobos can serve as an ice-breaker during intergroup social encounters or as a means for overtaking unexpected situations. In apes, play can act as a form of social currency that can rapidly shape social relationships as it occurs around feeding time. The more the play, the more the cofeeding. A strategic game, worthy of its name, must rely on a complex communication based both on intentional and emotional components. In the same way, play in primates is a fertile field to explore how signals are integrated into complex and multimodal systems. In this view, play provides a window into the study of social cognition, emotional regulation and the evolution of communicative complexity.