Overjustification Effect

What is the overjustification effect?

The overjustification effect refers to a reduction in interest in an already enjoyable activity after it is undertaken for an external reward. It concerns later motivation for the activity itself, rather than simply whether rewards increase performance while they are available.

Overjustification effect example and evidence

In Lepper, Greene, and Nisbett’s 1973 study, preschool children who already enjoyed drawing later chose to draw less after agreeing to draw for an award. Children given an unexpected award or no award showed more subsequent interest.

A 1999 meta-analysis of 128 experiments found that expected tangible rewards could reduce later free-choice engagement, while positive feedback could enhance intrinsic motivation. Praise and payment should therefore not be treated as interchangeable.

Why can rewards change intrinsic motivation?

The original overjustification account emphasized attributing one’s behavior to an external reason. Self-determination theory offers another account, emphasizing how a reward affects perceived autonomy or competence. The observed reduction does not establish one explanation in every case.

When does the overjustification effect occur?

These findings do not mean that rewards always undermine motivation. Effects depend on the activity, the reward arrangement, and the outcome measured.