Abstract
The purpose of the present study was to evaluate Herrnstein's law of effect as a description of socially significant behavior in an applied setting. The subject was an 18-year-old retarded girl with a history of autistic-like and aggressive behavior. Using a baseline design for two response classes and stimulus conditions, eight categories of subject and staff behavior were monitored over a 3-week period. A computerized observation system, developed for use in the present investigation, was used to obtain real-time durations of the behavior categories alone and in combination. Overlapping durations of teacher and subject behavior were then correlated to yield approximations to a functional definition of reinforcement. Plots of behavior by contingent reinforcement revealed a hyperbolic relationship for each response class, the shape of which varied as a function of extraneous reinforcement r0. In addition, estimated parameters in Herrnstein's equation did not differ significantly from those obtained through independent observation. Finally, Herrnstein's equation accounted for an average 63% of variance in response allocation. Results are discussed in terms of the relevance of matching-law theory to behavior in applied settings.