Hopping, skipping or jumping to conclusions? Clarifying the role of the JTC bias in delusions.

Abstract

INTRODUCTION: There is substantial evidence that patients with delusions exhibit a reasoning bias--known as the "jumping to conclusions" (JTC) bias--which leads them to accept hypotheses as correct on the basis of less evidence than controls. We address three questions concerning the JTC bias that require clarification. Firstly, what is the best measure of the JTC bias? Second, is the JTC bias correlated specifically with delusions, or only with the symptomatology of schizophrenia? And third, is the bias enhanced by emotionally salient material? METHODS: To address these questions, we conducted a series of meta-analyses of studies that used the Beads task to compare the probabilistic reasoni..