Abstract
Primates are social animals. This article reviews the studies concerning the social behavior of Old World monkeys and describes the following three points: (1) primates live in a complex and dynamic social group, (2) they have the relatively large neocortex and the relatively long juvenile period as an extended learning period to manage their complex social environments, and (3) primate infants are socialized and acquire complex social skills through the interactions with their mothers. Because the sociality of primates plays an important role in their daily lives, a better understanding of the primate minds is required to investigate the effects of the social environment on their social intelligence.
