Turning play into work: Effects of adult surveillance and extrinsic rewards on children's intrinsic motivation.

Preschool children engaged in a novel activity in individual sessions. In the expected reward conditions, subjects expected to win a chance to play with highly attractive toys by engaging in the activity; in the unexpected reward conditions, subjects had no prior knowledge of this reward. Orthogonally, subjects in the surveillance conditions were told that their performance would be monitored via a television camera; while subjects in the nonsurveillance conditions were not monitored. Two weeks later, unobtrusive measures of the subjects' intrinsic interest in the activity were obtained in their classrooms. Two significant main effects were obtained reproducing and expanding findings from earlier studies. Subjects who had undertaken the activity expecting an extrinsic reward showed less subsequent interest in the activity than those who had not expected a reward, and subjects who had been placed under surveillance showed less subsequent interest than those not previously monitored.