Undermining children?s intrinsic interest with extrinsic reward: A test of the ?overjustification? hypothesis.

Lepper, R. M., Greene. D., Nisbett. E. R., (1973) Personality and Social Psychology, 28, 129-137

This study looks at what happens when children are given rewards for engaging in an activity which they find pleasurable.

Children who have the desire to engage in an activity because they enjoy it or find it interesting, not because of external rewards or pressures, will spend time participating in the particular task for enjoyment- this is known as ?intrinsic motivation?. Extrinsic motivation, on the other hand, is when a child?s desire to engage in an activity is not motivated by the fact that they find the task interesting or enjoyable but because there is external rewards or pressure to do so. This study examines what happens when a child is rewarded for an activity which they enjoy doing. The experimenters hypothesise: children undertaking an activity which they naturally enjoy, with the knowledge that they will gain something for doing this, will have the unwanted effect of undermining that child?s initial enjoyment of the activity, resulting in the child being less likely to gravitate towards, or participate in, the same activity at a future date. They predict that it is not the reward itself e.g. money or a sticker which will interfere with intrinsic motivation rather it is because the child is now doing the task for a reason other than personal satisfaction.

51 children ranging in ages from 40 months to 64 months were recruited. Intrinsic motivation was measured, through observations, by the degree of initial interest in drawing. Based on intrinsic interest, subjects were randomly assigned into 1 of 3 treatment conditions: expected award, unexpected award and no award. In the first and second case children were rewarded with a certificate for participating in a drawing task. However the first group were told beforehand that they would receive the reward while the second group had no knowledge of the reward until after the task. The ?no award? task group neither expected nor received an award. These experimental sessions were conducted individually in a room apart from the subject?s classroom. 1-2 weeks after these sessions, the target drawing activity was again introduced to the classroom. Intrinsic interest was again measured through covert observation.

Once the study had ended and the children no longer received rewards for drawing, each group was assessed for motivation to engage in the original task. In the ?expected award? condition children displayed a decreased interest in the drawing activity, after having undertaken the task in order to obtain a goal which was extrinsic to the pleasures and satisfactions of drawing. The ?unexpected award? group showed undiminished or increased interests in the reward. Lepper et al suggest that the decrease in intrinsic motivation, experienced by the expected award group, can be explained by the ?overjustification? effect which is the tendency of people to view their behaviour as caused by compelling extrinsic reasons, making them underestimate the extent to which it was caused by intrinsic reasons.

In conclusion this study illustrates the undermining effects of setting up rewards for tasks which children naturally enjoy. The authors' review the implications this has for education and parenting. Specifically, this is important in the educational setting, one of the central problems facing educators is the inability to preserve intrinsic interest in learning and exploration in children. The authors do support the use of extrinsic incentives in certain circumstances to increase interest, e.g. when intrinsic interest is low or if attractiveness of an activity only becomes apparent experientially. Overall this study has highlighted the undesirable consequences of the unnecessary use of extrinsic rewards, and that careful attention should be made if, and when they are used.