Contrasting the Ironic Monitoring and Motivational Explanations of Postsuppressional Rebound

Suppressing a thought often results in postsuppressional rebound, that is, a subsequent increase in the incidence of the suppressed thought. The present study was designed to distinguish between two explanations of rebound: Wegner's 1994 ironic monitoring theory and Liberman and Forster's 2000 motivational account. Participants (99 Deakin University students) first suppressed, then expressed, thoughts of a white bear. In some conditions, a delay—presented as occurring either intentionally or unintentionally—between suppression and expression was introduced. In other conditions, participants concurrently completed a memory task and were encouraged to attribute the difficulty of suppression either to this task or to the requirement of suppression. An intentional delay, but not an unintentional delay, reduced rebound, while attributing difficulty to the suppression requirement was associated with greater rebound than was attributing it to the memory task. The results are interpreted as supporting Liberman and Forster's motivational account of rebound.