Laboratory control of thumbsucking by withdrawal and re-presentation of reinforcement.

A 5-year-old boy was shown cartoons, and punished for thumbsucking during alternate cartoons by turning off the cartoons for as long as his thumb remained in his mouth. Thumbsucking weakened during such periods. During alternate periods of uninterrupted cartoons, thumbsucking promptly recovered, suggesting a quick discrimination process. Two other 5-year-old boys were shown the same cartoons; withdrawal of the cartoons was made contingent upon thumbsucking for one, and randomly yoked for the other. Then their roles were reversed. Contingent withdrawal and re-presentation of the cartoons controlled thumbsucking rate; yoked withdrawal and re-presentation did not.