A Human-Operant Investigation of Preceding- and Following-Schedule Behavioral Contrast

Abstract

Behavioral contrast occurs when a change in the rate of reinforcement in one context results in a change in behavior in the opposite direction in another context. Research findings with nonhumans regarding the symmetry of positive and negative contrast have been mixed, especially regarding the relative influence of preceding and following schedules of reinforcement. Research has also been mixed regarding the extent to which systematic within-session contrast is demonstrated. Despite applied implications of contrast, the vast majority of research has been conducted with nonhumans. The purpose of the current study was to investigate the differential influence of preceding- and following-schedules of reinforcement on positive and negative behavioral contrast, as well as within-session contrast, with adult humans with intellectual and/or developmental disabilities in a 3-component human-operant arrangement. Positive contrast was found in 5 of 6 cases, whereas negative contrast was found in only 2 of 6. The effect of the following schedule was larger with positive contrast, but the effect of the preceding schedule was larger with negative contrast. There were no systematic within-session effects characteristic of behavioral contrast.