Qualitatively Varied Reinforcement: A Replication of Steinman (1968)

Abstract

Steinman (1968a) conducted the first experiment using a free-operant procedure to compare the effects of qualitatively varied reinforcers versus constant reinforcers in rats’ lever pressing. Steinman found that varied reinforcers maintained higher relative response rates. Steinman’s finding is inconsistent with recent studies showing that constant reinforcers produce higher rates of responding than those produced by
varied reinforcers. To assess the replicability of Steinman’s finding, an experiment was conducted using the same general methods as described by the author. Four rats were exposed to a three-component multiple schedule. In each component, lever presses were maintained by a chained variable-interval 45 s, fixed- ratio 1 schedule. Either sucrose solution or pellets were delivered in two constant reinforcer components and sucrose solution and pellets were delivered alternately in the
varied reinforcer component. There were no systematic differences in response rates across the three components of the multiple schedule. Steinman’s finding cannot be replicated under conditions other than the circumscribed set of variables present in his experiment, thus it lacks generality. The implications of replication failures in behavior analysis and the use of qualitatively varied reinforcers in applied settings
are discussed. New directions for future research are suggested.