Similarity on the rebound: inhibition of similarity assessment leads to an ironic postsuppressional rebound.

A widely held but rarely tested assumption among cognitive scientists is that different cognitive tasks may rely upon a single basic cognitive process. Using an established methodology to examine the suppression and subsequent rebound of mental operations, the present research indicates that suppressing use of similarity in one domain results in the subsequent rebound of similarity assessment in a different domain, suggesting that both domains rely on the same underlying cognitive process. In two studies, we demonstrate that leading people to suppress natural similarity assessment in one task produces increased reliance on similarity in subsequent, different, and apparently unrelated tasks. In Experiment 1, participants led to suppress similarity in a concentration task subsequently made more errors in a false-memory paradigm than did control participants. In Experiment 2, participants suppressing similarity in a categorization task made more false-memory errors and perceived more similarity between word pairs than participants who did not suppress. The findings suggest that the cognitive process of similarity assessment may be a domain-general process, such that it is widespread across a number of different mental tasks.