Compared with dogs (Canis familiaris), the social cognitive abilities of cats (Felis catus) have not received much research attention, probably because cats are not considered to be as social as dogs. However, cats have in fact developed sociality in conspecifics and, needless to say, cat-human relationships after their domestication. This paper initially considers the reasons behind the underestimation of cats' social abilities, and then reviews social behavior among conspecifics and in the cat-human relationship. Several studies have provided evidence that cats possess social intelligence. Since their intelligence is considered to be expressed in different context from that of dogs, methods different from those used to study dogs are therefore needed for investigating their social abilities. Appropriate experiments or devices will undoubtedly unravel the high social intelligence of cats.
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.