Thirty two subjects of high school age were tested under two experimental conditions on a variety of tasks. Subjects in the extrinsic-incentive condition were promised a reward for their participation in the experiment No mention of reward was made in the no-incentive condition. Consistent with die experimental hypothesis, it was found that subjects in the latter as opposed to the former condition exhibited superiority in creativity of performance and task recall. In addition, they manifested a stronger Zeigarnik effect, and reported greater enjoyment of the experiment The data were discussed in reference to the idea that the degree of intrinsic motivation for a task is determined by the actor's self-attributed cause for its performance