Social play in crested and Japanese macaques: testing the covariation hypothesis.

Most studies about social play have focused on its function in aiding socialization. It is not known whether play patterns vary by species according to specific adult social relationships. To test whether there is covariation between the form of play interactions and adult relationships, we studied social play in Japanese macaques (Macaca fuscata) and crested macaques (Macaca nigra). Comparative studies have shown that whereas low levels of tolerance and strict hierarchies characterize Japanese macaques, crested macaques display greater tolerance and relaxed dominance. The results showed that the former prefer less risky games, with minimal physical contact, ease of escape and a small number of play partners. The play bouts of the latter species involve closer contact and more partners. We conclude that play patterns covary with specific social style. Play patterns could have been selected for to introduce youngsters to their future social environment.