Social and solitary play in a colony of vervet monkeys (Cercopithecus aethiops).

This study describes and defines play in a laboratory colony of vervet monkeys (Cercopithecus aethiops). Play is divided into 26 units of behavior and the frequencies of these behaviors are recorded. Analysis shows that sex, age, and dominance have effects on some play behaviors. The play behavior of each age/sex group within the colony is described both quantitatively and qualitatively. Adult females are characterized by reinforcement of the play of immature monkeys, adult males by rough play with older male juveniles, four-year-old females and three-year-old males by stimulation of play in young infants, and males in general by a preference to play within their peer group. It is suggested that modified repetition of behaviors, diversified interactions, and innovative behaviors, are important qualities of play, and are essential to the adaptive plasticity of behavior in primates.