External Reward Undermine intrinsic Motivation – Study of Studies

Topic: Tangible reward effect on intrinsic motivation
Researchers: Edward L. Deci (Professor of Psychology and Social Science, University of Rochester, US), Richard M. Ryan (Professor of Clinical and Social Psychology, University of Rochester, US), and Richard Koestner
Published At: Psychological Bulletin
Year: 1999
Formal Reference: Edward L. Deci, Richard M. Ryan, and Richard Koestner, “A Meta-Analytic Review of Experiments Examining the Effect of Extrinsic Rewards on Intrinsic Motivation”, Psychological Bulletin 125, no. 6, 627-668
Main Conclusion: The introduction of external tangible reward undermines intrinsic motivation.

Researchers analyzed 128 experiments, which spread for almost three decades, and concluded that tangible rewards tend to have substantially negative effect on intrinsic motivation.