SHOULD BEHAVIOR THERAPISTS STOP USING REINFORCEMENT - A REEXAMINATIONOF THE UNDERMINING EFFECT OF REINFORCEMENT ON INTRINSIC MOTIVATION

In two experiments the effect of monetary reinforcement on college stu dents' intrinsic motivation was examined in an attempt to compare two competing explanations of the effects of tangible reinforcement on int rinsic motivation: discrimination training and cognitive evaluation th eory. In Experiment 1, students were administered the typical methodol ogy used to study the effects of tangible reinforcement on intrinsic m otivation with the addition that the verbal instructions prior to the posttreatment session that inform participants regarding the lack of r einforcer availability were manipulated experimentally. The results su pported the hypothesis that discrimination training accounts for the u ndermining effect. Experiment 2 replicated the findings of Experiment 1 and included tests of the cognitive evaluation theory account of the undermining effect. Several results of Experiment 2 were inconsistent with predictions based on cognitive evaluation theory, whereas the di scrimination training hypothesis received additional support. The adva ntages of the discrimination training account of the undermining effec t and the implications for the use of reinforcement in applied setting s were discussed.