Overjustification Effect

Overjustification Effect Definition

Overjustification occurs when play becomes work as a result of payment or other reward. More formally, it is the process by which intrinsic interest in some activity or behavior is supplanted through the presentation of an extrinsic reward. An activity that was once interesting in and of itself becomes less interesting and less attractive after a person is rewarded for completing the activity. This leads to the ironic and surprising result that rewarding a behavior can inhibit future repetitions of that behavior.

Overjustification EffectThe overjustification effect occurs when internalized motives are supplanted by external motives. It occurs because people do not have perfect access to the preferences and motives that guide their decision-making processes. These preferences are often inferred from observation of their own behavior, and sometimes people get it wrong. When two motives exist for a given behavior—both internal and external—people often assume that the more obvious external justification is the cause of their behavior. This observation leads to a permanent change in how people think about the given activity, and it can lead to a loss of the internalized motives for the behavior. Thus, large rewards can extinguish the inherent joy of some positive activity, and large punishments can extinguish the moral inhibitions against some negative activity.

Intrinsic and Extrinsic Reward

Some activities, such as eating, drinking, learning, and socializing, are intrinsically interesting, and people pursue them with little encouragement. Other activities are usually performed only to gain an external reward. For instance, people typically go to work only because they are paid, and children make their beds or take out the trash for praise or an allowance. These behaviors are rewarded by extrinsic sources, and when the rewards stop, so too do the behaviors. Thus, some behaviors are intrinsically rewarding, and some are extrinsically rewarding. In all cases, the rewards lead to an increased likelihood of repeating the given behavior.

However, something strange occurs when extrinsic rewards are given for activities that are already intrinsically interesting. At first, as long as both rewards are present, the person continues the activity. But when the extrinsic rewards are removed, the person stops performing the activity, as if his or her intrinsic interest had been wiped away.

Consider the classic experiment among nursery school students conducted by Mark Lepper and his colleagues. These students were given the opportunity to draw pictures with an attractive set of Magic Markers during their free play time. Hidden observers recorded their behavior and learned, not surprisingly, that children needed little encouragement to play with the markers. Several weeks later, these same students were given another opportunity to play with the markers. But this time some of the students learned that they would receive a very special “good player” award with a ribbon and gold star if they were willing to draw some pictures; others were simply invited to draw for fun. Thus, the experiment had two groups of students involved in an activity with high intrinsic interest: one that received a reward for playing, and one that did not. Several weeks later, the students were again monitored when the markers were brought out during playtime. The results were very clear: Children who had been given an extrinsic reward showed far less interest in playing with the markers than did the children who were not offered the reward. Something about the reward had reduced the children’s desire to play with the markers.

These findings are best explained through self-perception theory, which states that people learn about their likes and dislikes by observing their own behavior, and then making inferences from those observations. In this example, the children in the reward condition observed that they had chosen to play with the markers, but they also observed that they were rewarded for that behavior. They concluded, in retrospect, that the reward was the primary reason they had played with the markers. Because no reward was offered for drawing during the subsequent free play period, they chose not to play with the markers. The other students, however, who had not received a reward, saw the scene differently. They observed their previous decision to play with the markers but lacked any obvious explanation for that behavior. In the absence of any other reason, they concluded (correctly) that they must have played with the markers because they enjoyed playing with markers.

This experiment, and the hundreds like it, indicate that human preferences are somewhat more fragile than people expect. When people are given two good explanations for their own behavior (e.g., an external reward and intrinsic interest), they tend to assume that the more obvious and salient explanation is correct. The external reward is generally more obvious and salient than the intrinsic interest is.

Overjustification Effect Applications

The importance of the overjustification effect lies in its broad application to everyday life. Most people’s intuition follows the logic that if one wants to encourage a person to perform an activity, one should offer rewards for doing so. This logic is correct when the activity is inherently unpleasant or unattractive, but not when the activity possesses intrinsic interest. For example, children naturally require little encouragement to learn about their environment and how their world works. This natural curiosity fades in school, and the typical student finds classes and schoolwork downright onerous. There are, no doubt, many reasons for this change, but the fundamental structure of the American educational system and reliance on grading is responsible for a significant part of the decline. Although learning about history or mathematics can be inherently interesting, most students quickly come to believe that their only motivation for learning the material stems from the promise of a reward (an A), or the threat of a punishment (an F). Educational programs that have successfully removed or reduced the importance of grading have shown subsequent increases in intrinsic interest in the topics.

A similar dynamic has been observed when students are rewarded for reading books, completing assignments, or achieving good grades. Parents and teachers with good intentions unwittingly damage the very motivation they are trying to nurture. Beyond school, the effects of overjustification can be equally powerful. Many people choose a career based on their love of the activity, whether as a teacher, a lawyer, a wilderness guide, or a doctor. When the profession pays poorly and there is no overjustification, the original reason for joining the profession (intrinsic interest) remains salient. As a consequence, the person continues to love his or her work. But when the salary increases and provides its own justification, it tends to crowd out the original internal reason, and in so doing, permanently changes the nature of the job for that individual. The person comes to love the paycheck, not the work. Financially, it is always a boon to receive a raise; psychologically, there may be a cost associated with such good fortune.


Thus far, the examples have revolved around the effect of external rewards. However, the same conceptual process also applies to punishments and the inhibition of behavior. Imagine, for example, that you are taking an important test and are quite concerned about your performance. You have the opportunity to cheat and thus assure yourself of an excellent score, but choose not to do so. When you later ask yourself “Why didn’t I cheat?” your conclusion will likely be “it’s wrong to cheat.” In fact, the easier it was to cheat, the more strongly you would conclude that you believe cheating is wrong. Now imagine that there were several proctors closely watching the exam, and that you had been warned of severe consequences for any signs of cheating. When you ask yourself why you refrained from cheating, the salient explanation is “because I would have been caught.” As a result, you fail to internalize the belief that cheating is wrong, and you are less likely to conclude that you behaved in line with your moral beliefs. Thus, as the threat of punishment increases, the likelihood that a person will internalize the proscription against the behavior decreases.

This is not to say that punishment doesn’t work. It works extremely well, but only when the punishment is certain and swift. If you want to permanently inhibit a person’s negative behaviors without providing constant supervision (a goal of all parents and all societies), then it is necessary for that person to internalize the justification for his or her behavior (or, in the present case, the lack of behavior). Thus, the proper amount of punishment should be just sufficient to inhibit the targeted behavior, but not so severe as to provide an overwhelming external justification to the individual.


  1. Deci, E. L., & Ryan, R. M. (1985). Intrinsic motivation and self-determination in human behavior. New York: Plenum.
  2. Lepper, M. R., Green, D., & Nisbett, R. E. (1973). Undermining children’s intrinsic interest with extrinsic rewards: A test of the overjustification hypothesis. Journal of Personality and Social Psychology, 28, 129-137.