Does uncertainty breed conviction? On the possible role of compensatory conviction in jumping to conclusions and overconfidence in psychosis

Background: Jumping to conclusions (JTC) and overconfidence in errors are well established in individuals with a liability to psychosis. Experimental research suggests that subjecting individuals to dilemmas and doubt prompts a subsequent hardening of attitudes and may foster delusion-like convictions. For the present study, we examined whether this compensatory conviction process is exaggerated in individuals with a liability to psychosis and might in part explain JTC and overconfidence. Methods: A large sample of participants from the general population were screened for psychotic experiences with the Community Assessment of Psychic Experiences scale (CAPE) and then randomly allocated to either a condition in which they should experience doubt or a control condition. Participants (final sample, n = 650) were then tested on JTC and overconfidence. Results: Participants who scored high on the positive subscale of the CAPE made fewer draws to decision, showed greater confidence, and made more errors relative to low scorers. Yet, none of the parameters was modulated by experimental condition. Conclusions: Our results at present do not support the idea that JTC is elevated by a prior experience of a dilemma or doubt. Yet, this possibility should not be entirely dismissed as the presumed process may take time to evolve and perhaps needs to be more pervasive.