The overjustification effect occurs when an expected external incentive such as money or prizes decreases a person's intrinsic motivation to perform a task. Overjustification is an explanation for the phenomenon known as motivational "crowding out". The overall effect of offering a reward for a previously unrewarded activity is a shift to extrinsic motivation and the undermining of pre-existing intrinsic motivation. Once rewards are no longer offered, interest in the activity is lost; prior intrinsic motivation does not return, and extrinsic rewards must be continuously offered as motivation to sustain the activity.
Directional effects of rewards on motivation, depending on type of task, type of reward, and contingency of reward.
Motivation crowding theory
Motivation crowding theory is the theory from psychology and microeconomics suggesting that providing extrinsic incentives for certain kinds of behavior—such as promising monetary rewards for accomplishing some task—can sometimes undermine intrinsic motivation for performing that behavior. The result of lowered motivation, in contrast with the predictions of neoclassical economics, can be an overall decrease in the total performance.
Volunteer firefighters serve alongside paid professionals in many communities. Motivation crowding theory posits that these two kinds of firefighters might perform differently based on how they are paid.
