Too Much Reward *

David A. Gershaw, Ph.D.

If you want someone to do something, they are more likely to do it or continue to do it if you reward their behavior. It seems logical that a greater reward will increase the desired behavior even more. However, psychological evidence shows that under some conditions you can reward a person too much.

A 1973 psychological study illustrated this point with nursery school children, who liked to draw pictures without receiving any reward. The children were randomly assigned to three groups. The first group was asked by the experimenter to draw some pictures and even promised a reward if they did so. The second group was also asked to draw some pictures, but they were given an unexpected reward after they had completed the pictures. Children in the third group received no reward for drawing the pictures.

Weeks later, all of the children were placed in a situation where they could draw, if they wanted to do so. The amount of time they spent drawing was recorded. As shown in the figure, children who were initially offered the reward for drawing spent less than half of the time drawing as the children in the other two groups. The previous reward seemed to have reduced their interest in drawing.

In a similar way, a 1968 study offered psychiatric patients either $8 or $2 a month to attend therapy sessions. (You need to remember that these were 1968 dollars rather than the inflated ones we have now.) As most people would expect, the $8 reward increased attendance of therapy sessions in comparison to attendance before the reward was offered. However, when the reward was discontinued, the attendance rate dropped below the pre-reward level. In the $2 condition, attendance also increased. In contrast to the $8 condition, attendance remained high even after the $2 reward was stopped. Again, the larger reward was not more effective in keeping interest in the desired behavior even though it initially increased attendance.

One explanation for the behavior of both the children and the patients was proposed by social psychologist Daryl Bem with his self-perception theory. In many situations, people make attributions for their behavior they attempt to explain why they acted in a certain way. Depending on their attribution, they may decide not to continue the behavior.

With the children, all initially had intrinsic motivation they did the act merely for the pleasure of doing it. They engaged in drawing merely because they liked to draw. When the first group was asked to draw for a reward, the explanation for their behavior changed. They perceived themselves drawing because of the promised reward. Later, they were less likely to intrinsically engage in drawing, because they explained their previous drawing behavior solely as a means to get a reward. Of course, the children in the unrewarded group still believed that they liked to draw. The same is true of the unexpectedly rewarded group, since they do not view the reward as the reason for their behavior.

Likewise, the patients also made after-the-fact attributions of their behavior. When the large reward was stopped, these patients might have asked themselves some specific questions.

"Why am I attending these sessions? Should I continue to attend the sessions?"

With the large reward, they were more likely to conclude that they were attending for the reward not because they enjoyed the sessions or were being helped by them. So when the rewards were discontinued, they had no reason to attend. This was less likely to happen with the smaller reward.

This has some implications for teaching. Some teachers use rewards to get children to engage in learning activities. However, these rewards can undermine whatever intrinsic interest the students might have had in relation to the activities. In the long run, these rewards can be counter-productive. A 1976 psychological study found that students were more willing to work on math problems if they were offered rewards. Unfortunately when the rewards stopped these students were less motivated to do math than students who were never rewarded. If we want students to continue to have interest in various academic activities after they leave our schools, a high level of rewarding participation does not seem to be the answer.

However, that does not mean that all reward is counter-productive. More recent studies done in 1979 and 1980 indicate that reward will not necessarily reduce intrinsic motivation for learning. To avoid the problem, the reward needs to be seen as a reward for competent performance in contrast to rewarding just as a means to get the child to participate. In other words, the reward needs to be given for excelling in a task rather than merely doing it.

* Adapted from Louis Penner's Social Psychology: Concepts and Applications, West Publishing, 1986, pages 436-437.

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