Schedule-induced stereotypy.

The phenomena of the induction and entrainment of adjunctive behaviours was investigated in eight people with severe or profound mental retardation who exhibited stereotypic behaviours. The occurrence of collateral behaviours was investigated under extinction and massed reinforcer baselines and a variety of periodic or intermittent schedules of reinforcement for the performance of a simple experimental task. Seven of the eight subjects demonstrated evidence of schedule-induced stereotypic behaviour in the experimental conditions: five of the eight subjects also showed evidence of the entrainment of these behaviours within the first third of the interreinforcement interval. The results are discussed in relation to the analysis and intervention of problem behaviours in people with severe or profound mental retardation.