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Overjustification Effect: Why Rewards Reduce Motivation

  • The overjustification effect occurs when outside rewards diminish intrinsic motivation for an activity.
  • Example: paying kids for chores may lead to their reluctance to help unless compensated.
  • Unexpected reward that provides information about the performance can avoid overjustification.

What is overjustification effect

An overjustification effect, or undermining effect, occurs when a person engages in an intrinsically rewarding activity for an external reward. This reward then causes a decrease in the person’s subsequent intrinsic interest in that activity.

When parents use rewards and punishments to motivate their children to study or do household chores, they are often baffled by inconsistent results. 

At first, they seemed to work, but then they stopped working. What happened?

Soon, parents are angry and frustrated because they have tried multiple types of rewards and punishments but nothing works.

girl sits against a pile of books reading book and dreaming about trophy. Her desire is overjustified by external factors.

Intrinsic vs. extrinsic motivation

There are two types of motivation – intrinsic motivation and extrinsic motivation.

Intrinsic motivation occurs when people perform an activity out of interest because they derive spontaneous satisfaction from it. The feeling of satisfaction is an internal reward that creates the person’s intrinsic motivation.

Extrinsic motivation, on the other hand, requires a link between an activity and a separable outcome. Satisfaction does not arise from the activity itself but rather from the external incentive or consequences it produces.

So, when children engage in an activity they enjoy, they are intrinsically motivated. When they do it for an extrinsic reward or to avoid punishment, they are extrinsically motivated.

Parents who have tried everything, but nothing works, typically use external factors, rather than intrinsic reasons, to instill extrinsic motivation in their children.

Classic experiment

To understand why punishments and rewards don’t work well, let’s examine a classic field experiment by David Greene and Mark Lepper.

In the study, preschoolers were asked to participate in coloring activities they were very interested in. Some children were offered a reward for completing the activity while others were not. After several weeks, the children were given another opportunity to participate in the activity without a promise of a reward. Those who had previously been given a prize showed less interest in the activity than those who had never been offered one​1​.

This is an example of the overjustification effect.

Inducing a child to engage in an activity for an extrinsic goal undermines their initial internal drive to do it. Introducing extrinsic factors turns play into work. As a result, they no longer color for its own sake but rather to earn a reward.

mother watches daughter color overjustifying the activity


The shift in motivation can be explained by two main theories. They are the self-perception theory and cognitive evaluation theory, which later expanded into the self-determination theory​2​.

Self-perception theory

The self-perception theory, proposed by Lepper, Greene, and Nisbett at the University of Michigan, suggests that when offered extrinsic motivators, people rethink their reasons for engagement. They no longer perceive the enjoyable activity merely as such. The introduction of rewards overjustifies the prior intrinsic reason to engage in it​3​.

Since they get paid for the activity, this has caused them to rethink their reasons for doing it. 

Following a reward, someone who initially performs an activity for enjoyment will be less likely to do it again for no reward.

Intrinsic enjoyment is no longer enough reason. In the absence of external reinforcement, they see no point in doing it​4​.

Cognitive evaluation theory (CET)

In cognitive evaluation theory, another possible explanation proposed by Edward Deci, professor of psychology at the University of Rochester, intrinsic motivation is determined by a person’s need to feel competent and self-determined. 

Offering an extrinsic factor for engaging in an intrinsically interesting activity changes a person’s perception of competence or self-determination, diminishing their intrinsic desire​5​.

Self-determination theory (SDT)

In contrast to the cognitive evaluation theory that focuses on differentiating intrinsic and extrinsic motivations, the self-determination theory makes clear the difference between autonomous motivation and controlled motivation​6​.

Individuals with autonomous motivation feel in control of their decision to participate. 

Engaging in an activity because it interests them is entirely voluntary. Therefore, intrinsic motivation is autonomous. 

A controlled motivation, however, involves acting in a pressured manner, accompanied by the feeling of being forced into the activities.

SDT suggests that these three innate human needs underline autonomous motivation:

  • Autonomy – free to decide whether to take on an activity
  • Competence – feel capable and competent
  • Relatedness – feel connected with others

By rewarding children for an activity, their feelings of autonomy are compromised. The activity no longer feels voluntary, and therefore autonomous motivation is reduced.

overjustification teenage girl studies hard no justification effect


The overjustification effect is a common phenomenon in parenting. 

“Positive reinforcement” in the form of rewards is often used by parents to motivate their children’s compliant behavior. By doing so, they decrease their children’s intrinsic motivation to behave and instill the wrong values in them.

boy gets dollar bill for doing chores meet the overjustification effect psychology definition

Paying for chores

Contributing to the family by keeping the house clean and tidy should be the primary reason for kids to do chores.

However, children’s perception of chores changes when they are paid to do so. They realize they should no longer do it “for free.”. If parents don’t keep paying, they don’t feel obligated to help around the house.

The kids have been taught that chores are no longer about family contributions. Instead, chores are about making money.

According to research, children rewarded for doing chores tend to be less altruistic. Paying for chores instills an entirely different value in kids.​7​.

overjustification teenager studies for money overjustifying reasons for learning

Paying for good grades

Another common parenting tactic that exemplifies the overjustification effect is providing financial incentives for good grades.

Learning about the world around us is inherently fun and an intrinsic reward. Toddlers love getting into everything and exploring it all.

But when children receive a contingent financial reward, learning ceases to be a fun autonomous task.

It turns out that once parents start this practice, they have to keep paying to maintain good performance. It becomes increasingly difficult to get children to study or do homework without the help of external motivators. Parents have to keep increasing the reward.

Eventually, it stops working when the child has no internal motivation left.

Overjustification effect vs. operant conditioning

To classical conditioning theorists, the overjustification effect is an anomaly.

The overjustification effect is controversial because it challenges previous psychological findings on the effectiveness of reinforcement in altering animal and human behavior.

Both theories have merit under different conditions, and finding the right balance can be tricky thing for parents.

Here are three ways to provide children with positive affirmation without a detrimental effect on their motivation.

overjustification dad celebrates son winning soccer game

Form of reward

Whether an extrinsic reinforcement hurts a child’s overall performance depends on the reward used.

When rewards do not reflect the ability level, they lead to less intrinsic motivation. But rewards that incite feelings of competence, such as verbal praise or positive feedback, can result in greater intrinsic motivation.

In place of incentives, verbal rewards that emphasize informational aspects can complement the child’s competency or skill development​8​.

“You worked hard and didn’t give up even though it was tough initially. You persevered!”

Type of tasks

Activities can be categorized schematically into expressive or instrumental tasks.

Expressive tasks are play that evokes positive emotions and intrinsic motivation naturally.

Instrumental tasks are means to separate outcomes, such as rewards and punishment.

An expressive task feels like play, and the participant experiences it as intrinsically motivating. An instrumental task is perceived as work, and the individual participates only to reap other rewards.

Overjustification occurs when the perceived characteristics of a task change from being expressive to being instrumental​9​.

So, when children are rewarded for playing puzzles, they are more likely to experience a decrease in internal drive than those mowing the lawn.

Expectation of reward

Rewards aren’t always a bad thing. 

Parents sometimes give children gifts to recognize and celebrate their achievements. Using unexpected rewards sparingly has not diminished one’s intrinsic motivation​10​.


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    Greene D, Lepper MR. Effects of Extrinsic Rewards on Children’s Subsequent Intrinsic Interest. Child Development. Published online December 1974:1141. doi:10.2307/1128110
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    Pretty GH, Seligman C. Affect and the overjustification effect. Journal of Personality and Social Psychology. Published online 1984:1241-1253. doi:10.1037/0022-3514.46.6.1241
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    Lepper MR, Greene D, Nisbett RE. Undermining children’s intrinsic interest with extrinsic reward: A test of the “overjustification” hypothesis. Journal of Personality and Social Psychology. Published online 1973:129-137. doi:10.1037/h0035519
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    Tang SH, Hall VC. The overjustification effect: A meta-analysis. Appl Cognit Psychol. Published online October 1995:365-404. doi:10.1002/acp.2350090502
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    Deci EL, Cascio WF, Krusell J. Cognitive evaluation theory and some comments on the Calder and Staw critique. Journal of Personality and Social Psychology. Published online 1975:81-85. doi:10.1037/h0076168
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    Gagné M, Deci EL. Self-determination theory and work motivation. J Organiz Behav. Published online April 14, 2005:331-362. doi:10.1002/job.322
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    Fabes RA, Fultz J, Eisenberg N, May-Plumlee T, et al. Effects of rewards on children’s prosocial motivation: A socialization study. Developmental Psychology. Published online 1989:509-515. doi:10.1037/0012-1649.25.4.509
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    Rosenfield D, Folger R, Adelman HF. When rewards reflect competence: A qualification of the overjustification effect. Journal of Personality and Social Psychology. Published online 1980:368-376. doi:10.1037/0022-3514.39.3.368
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    Sandelands LE, Ashford SJ, Dutton JE. Reconceptualizing of the overjustification effect: A template-matching approach. Motiv Emot. Published online September 1983:229-255. doi:10.1007/bf00991675
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    Fazio RH. On the self-perception explanation of the overjustification effect: The role of the salience of initial attitude. Journal of Experimental Social Psychology. Published online July 1981:417-426. doi:10.1016/0022-1031(81)90048-2


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