Behavior of rhesus monkeys raised in isolation

A large number of animal studies have demonstrated the important influences of experience acquired during infancy and childhood on later behavior. (For views see Beach and Jaynes1, and Denenberg2.) In his discussion of parameters relevant to studies concerning the effects of early experience on adult behavior patterns. King3 recognizes seven variables as particularly significant. Among these are included (a) the duration or quantity of the experience; (b) the type or quality of the experience, and (c) the type of performance measure obtained. This report is primarily concerned with the effects of the second of these factors, the type or quality of the experience, on the social and manipulatory responsiveness of young rhesus monkeys. In previous studies the social behavior of adolescent monkeys raised from infancey in individual wire mesh cages was compared with the behavior of wild-born animals the same age. Laboratory-reared monkeys fought more than feral animals, groomed less and were deficient in their sexual performance4. In the present experiment the behavior of pubescent monkeys reared in the ordinary laboratory environment, as were the restricted subjects of the earlier experiment, is compared with the behavior of monkeys exposed from infancy to a more severe form of environmental restriction.