Syntes: Cameron & Pierce (1994) — overall, rewards did not lower intrinsic motivation; only expected tangible rewards for simply doing a task had a minimal negative effect

Källa: Cameron, J.; Pierce, W. D. (1994). Reinforcement, Reward, and Intrinsic Motivation: A Meta-Analysis. Review of Educational Research 64(3), 363–423. https://doi.org/10.3102/00346543064003363

Verified content

• [abstract] 96 experimental between-groups studies: overall, reward does not decrease intrinsic motivation.
• [abstract] Verbal praise increases intrinsic motivation.
• [abstract] The only negative effect: expected tangible rewards given simply for doing a task — a minimal negative effect on time spent on the task after the reward is removed.
• [abstract] Five within-subject studies: reinforcement does not harm intrinsic motivation.

Limits

• [assessment] The 1999 meta-analysis by Deci, Koestner & Ryan re-analysed this literature with different coding and reached a stronger negative result; the dispute is mostly about coding and pooling. Abstract only.

Why it is in the library

The classic meta-analysis cited against the undermining effect; it narrows K48 to the one condition both sides agree on (expected tangible rewards for doing the task) and disputes its size.

Added 2026-10-18 by the project (weekly source sweep). [abstract] = from the published abstract; [full text] = read in the full text; [assessment] = the project's own assessment.