A further experimental investigation of thought suppression

It has often been suggested that attempts to suppress a thought will lead to an immediate and/or delayed increase in its occurrence. In a recent experiment (Clark, Ball & Pape, Behaviour Research and Therapy, 29, 253-257, 1991) we obtained a delayed (rebound) effect but failed to demonstrate an immediate enhancement effect. Lavey and van den Hout (Behavioural Psychotherapy, 18, 251-258, 1991) have suggested immediate enhancement might be observed only if subjects are instructed not to use distraction while suppressing. The present experiment tested this hypothesis. An immediate enhancement effect was not obtained but the delayed (rebound) effect was twice replicated and an artifactual explanation of this effect was discounted.