Reinforcement, behaviour constraint, and the overjustification effect.

It has been repeatedly demonstrated that reward contingencies and other extrinsic constraints on behaviour can lead to reduced levels of interest in and /or decreased engagement in a target activity in a subsequent noncontingent situation. It has been hypothesised that this effect is caused by a change in the self-perceived locus of motivation from intrinsic to extrinsic. It follows from this hypothesis that effective rewards are more likely to produce the overjustification effect than are ineffective rewards, However, a review of empirical studies suggests the opposite conclusion.