In the clinical literature, thought suppression is considered to play a role in the development of intrusion-related psychiatric syndromes, such as obsessive-compulsive disorder, acute or posttraumatic stress disorder, phobias, and addiction. This assumption goes back to a study by D. M. Wegner, D. J. Schneider, S. R. Carter, and T. L. White (1987) in which participants were asked to suppress thoughts of a white bear, an assignment that proved to be nearly impossible to complete. The present two studies sought to explore the influence of the content of control instructions on intrusion frequency in thought suppression experiments. Notably, during nonsuppression (i.e., control) periods, participants can either be instructed to think about white bears (i.e., expression instruction), or to think of anything including white bears (i.e., liberal instruction). Results indicated that expression instructions resulted in an increased number of target thoughts, while liberal instructions did not. Implications for the interpretation of thought suppression findings are discussed.

Instructions, Thought frequency, Thought suppression,
Journal of Psychopathology and Behavioral Assessment
Department of Psychology

Rassin, E.G.C, Muris, P.E.H.M, Jong, J, & de Bruin, G.O. (2005). Summoning white bears or letting them free: The influence of the content of control instructions on target thought frequency. Journal of Psychopathology and Behavioral Assessment, 27(4), 253–258. doi:10.1007/s10862-005-2405-9