DO ANIMALS SATIATE OR HABITUATE TO REPEATEDLY PRESENTED REINFORCERS

Operant response rates may decrease within experimental sessions. The most likely explanation for the decrease is that satiation or habituat ion reduces the effectiveness of the repeatedly presented reinforcer. We argue that, contrary to intuition, both empirical and formal argume nts favor habituation over satiation. Attributing the decreases in ope rant responding partly to habituation challenges the traditional assum ption that habituation alters only reflexive behavior and does not occ ur to biologically significant stimuli. It preserves common terminolog y during operant and classical conditioning and when appetitive and av ersive stimuli are used. It may provide a relatively general descripti on of temporal changes in behavior in a wide variety of situations and may help to integrate motivational variables into theories of conditi oning.