Book Definition: The process by which extrinsic (external) rewards can sometimes displace internal motivation.

In Your Own Words

  • Internal motivation is weakened by the addition of an external reward.
  • Having less motivation or desire to complete a task due to receiving an award.
  • Losing interest in something you love because you are now forced to do it.
  • "Over doing it"


  • When children were given a reward for drawing, their desire to draw days later (without a reward) decreased. When they were told to draw but not given a reward, their desire to draw days later was the same if not heightened.
  • A child receives money for playing video games one day. A few days later, when money is no longer offered, the child does not want to play video games as much.
  • If you pay your child to make their bed every morning once you stop paying them, they will not want to fix their bed every morning.
  • When a guitar player plays guitar in a local bar because he loves to play, however he becomes famous, once famous he doesn't play at small bars or venues anymore because they offer less money.
  • Someone is being paid to do something that they like to do, but once that reward goes away, they don't want to do that activity anymore.
  • Before, you enjoyed cooking delicious dishes. When you are offered a job as a chef, the fulfillment you use to get from cooking vanishes.
  • Before, you enjoyed dancing because it was good exercise and you loved it, but now you are paid to dance and the fulfillment vanishes.
  • A former star high school and college quarterback's performance level may drop once he enters the NFL, where his intrinsic love of the game is replaced by a paycheck.
  • Your parents reward you with money to get good grades. Once they stop providing you with money, you feel less motivated to earn good grades.
  • A dog is rewarded with treats whenever it does a trick. Once you have stopped giving your dog treats, your dog doesn't seem to want to do tricks anymore.
  • Students study because they want good grades, but once teachers give everyone the same grades then the students don't want to study anymore.
  • You recieve a raise at work for being on time for 2 weeks straight, but once your boss stops increasing your pay, you no longer go to work on time anymore.

Additional Resources

  1. Greene, D., & Lepper, M. R. (1974). Effects of extrinsic rewards on children's subsequent intrinsic interest. Child development, 1141-1145.


  • David Greene and Mark Lepper, two Psychologists from Stanford, conducted an experiment in 1973 in order to test the theory of overjustification. This theory of overjustification hypothesized that if someone has an intrinsic motivationin doing something, introducing an extrinsic award for that interest, will actually in turn decrease there fondness of the activity/object/etc... These two men tested this theory by observing 3-5 year old nursery school children. They had 3 groups, all students who had an interest in some mutual activity. One group was told they were completing this activity for an award, another group got an award unexpectedly after completing the activity, and the final group was given no reward at all. At the end of this experiment, their results supported the theory of overjustification in that, the only group whose interest in the activity had decreased was the one in which they knew they were going to get an award. Although there was another group who received awards, they were not completing the activity in order to get the reward. Therefore, it was proven that extrinsic awards given to anyone who has an intrinsic motivation to do something, may in fact lessen their desire and motivation to do that activity.

  • Researchers, David Rosenfield, Robert Folger and Harold F. Adelman conducted research on overjustification on 188 female university students from Southern Methodist University. They had subjects play a word game and measured their interest under different systems of incentive. Two groups -- group one were told they would be rewarded on their quality of performance and group two were told they would be rewarded for completion. In group one above-average players would be paid more and below-average players less. In group two, regardless of their performance subjects were paid, scaled by the number repetitions or number of hours playing. Within group one subjects were split into two sub groups. Regardless of performance one subgroup one were told they over-performed and subgroup two were told they under-performed. Overall, subjects of the first group, in general, showed greater interest in the game and continued playing for a longer time than subjects of the second. Within group one, subgroup one, the "over-performers" continued playing longer than the "under-performers." However, it was the exact opposite in group two; "under-performers" continued playing longer than "over-performers." This experiment illuminated the relationship between requirements for reward and competence completing the cognitive task. When rewards did not reflect competence it was found that the higher reward the less intrinsic motivation. However, when rewards did reflect competence, higher rewards lead to greater intrinsic motivation. The researchers' study more clearly defined the "situation" in which overjustification takes effect. We mostly focus on the conditions set in group two to talk about overjustification, but the conditions set in group two and their effect were the big part of this experiment.