Control and early socioemotional development: Infant rhesus monkeys reared in controllable versus uncontrollable environments (1986)

Mineka, S., Gunnar, M., Champoux, M.

Abstract

For the Master group, responses on the operant manipulanda resulted in the delivery of the appropriate reinforcements [food, water, treats]. For the Yoked group, the manipulanda were inoperative; the occurrence of reinforcements was dependent on the actions of the Master group subjects. When a subject of the Master group successfully operated the manipulanda, both groups were simultaneously reinforced. ... Results indicated that Master subjects displayed less fear, as measured by reactions to a mechanical toy robot, and exhibited more exploratory behavior, as measured by responses to a standard primate playroom, than did Yoked subjects.