Does Intrinsic Motivation Theory Explain the Adverse Effects of Rewards on Immediate Task Performance?

In an effort to answer the question posed in the title, we assessed the effects of rewards on the immediate task performance of preschool children in two studies. Both studies had within-subjects, repeated measures designs, and both yielded highly consistent results showing a detrimental effect of reward on the Peabody Picture Vocabulary Test and on the Goodenough-Harris Draw-a-Man test. Performance decrements were confined to sessions in which subjects were rewarded; when rewarded subjects were shifted to nonreward, their performance improved dramatically. Although these studies were not concerned with the effects of reward on intrinsic motivation, the findings appear to present theoretical difficulties for current cognitive-motivational explanations of the adverse effects of material rewards on immediate task performance. An alternative viewpoint that material rewards can produce a temporary regression in psychological functioning is suggested.