Table of Contents:
Abnormalities in the reasoning-style of persons with schizophrenia are considered to be relevant aetiological factors in the development and maintenance of delusions. They are increasingly becoming the target of cognitive behavioural interventions for psychosis. In particular, the hasty decision-making by persons with delusions, titled as “jumping-to-conclusions” (JTC), has received great attention. It has been discussed as a relevant factor in the development of delusional beliefs, as it is likely to lead to a premature rejection of alternatives during the process of belief-formation and, therefore, contribute to erroneous inferences. The standard paradigm in this context is a probabilistic reasoning task, the so-called “beads task”.
Two main research questions were derived from previous findings. The first study investigates whether hasty decision-making in the beads task is associated with hasty decisions in tasks that are more relevant for everyday decision-making. In a second study it was examined if the JTC bias of participants with delusions can be reduced by rational arguments or altered motivational factors.
Taken together, it can be concluded that hasty decision-making is not linked to the specific characteristics of the probabilistic beads-task-paradigm, but although occurs with other decision-making task. Therefore, the results in the beads task can be generalized to decisions in other contexts. Furthermore, the results of the second study show that it is possible to influence the hasty decision-making behaviour of delusional patients. This underlines the potential of interventions targeted at the JTC bias.