Relative preference for external and self-controlled reinforcement in monkeys

Monkeys were tested for their relative preference for self-monitored and externally imposed systems of reinforcement. One monkey clearly preferred to self-reward his own performances. whereas a second monkey favored slightly the externally administered system but displayed a small gradual shift toward self-reward as the sessions progressed. Unlike previous findings. unmerited self-reward did not result in rapid discarding of self-imposed performance requirements. The level of work output and the interactive effects of multiple reinforcement control are possible operative factors in sustaining self-imposed contingencies long after punishment for unmerited self-reward has been discontinued.