Combined Effects of Intrinsic and Extrinsic Rewards on Motivation

Abstract

Contrasting predictions from expectancy valence and cognitive evaluation theories were tested in a 2 × 2 factorial design in which intrinsic and extrinsic rewards were independently manipulated. Based on critiques of earlier research, several relevant factors were considered in the present design: type of extrinsic reward, measure of intrinsic motivation, and use of moderator variables, such as higher order need strength. 94 college students worked on either an interesting or boring task for a low or high extrinsic reward. The primary measure of intrinsic motivation was subjects' return rate to a second experimental session. Results support the expectancy valence hypothesis that intrinsic and contingent extrinsic rewards have an additive effect on motivation. Both types of rewards show significant main effects. There were no significant moderator effects. Differences between this study and research supporting cognitive evaluation theory are discussed.