The Over-Justification Effect
Research by Lepper, Greene, and Nisbett (1973). · Undermining children's intrinsic interest with extrinsic reward: A test of the 'overjustification' hypothesis (1973)
When an external reward is given for an activity that a person already finds intrinsically interesting, the person may later lose that intrinsic interest, believing they did it for the reward.
Core Concepts
The Problem
Parents, teachers, and managers often try to motivate by offering rewards for desired behaviors, inadvertently reducing the target's natural motivation.
The Claim
The over-justification effect demonstrates that external incentives can displace intrinsic motivation, causing the activity to be seen as a means to an end rather than enjoyable in itself.
Key Evidence
- •Lepper et al. (1973): Preschoolers who expected a reward for drawing spent less time drawing later than those not promised a reward.
- •Many subsequent replications across educational, exercise, and workplace settings.
Practical Implication
To preserve intrinsic motivation, rewards should be used sparingly and framed as recognition rather than as a condition for performance. Unexpected rewards are less detrimental.
Nuance & Limits
The effect is most pronounced for tasks that are already interesting. For uninteresting, routine tasks, rewards may be necessary and don't necessarily kill motivation. Tangible rewards (money, prizes) are more undermining than verbal praise.
Source Material
Citation Density
Thousands of citations, foundational in self-determination theory.
Gaps
- ⚠ Boundary conditions where external rewards do not undermine intrinsic motivation are not fully mapped.
- ⚠ Cross-cultural variability in the effect requires further study.
Discuss Further
Open this concept in an AI assistant for deeper discussion, critique, or exploration.