This article reviews evidence from basic and translational research with pigeons and humans suggesting that the persistence of operant behavior depends on the contingency between stimuli and reinforcers, and considers some implications for clinical interventions. (Contains 4 figures.)

"JEAB"'s first decade featured control of individual behavior by operant contingencies, where the experimenter could interact with a subject in real time and obtain fairly immediate evidence of control, with the possibility of direct extension to applied settings. In subsequent decades, emphasis shifted toward long-term parametric studies with…