Over the years, there have been a number of influential studies into the reasoning processes of deluded and delusion-prone individuals. Most of these studies used an approach consistent with the prevailing diagnostic definition of delusions, according to which delusional beliefs are based on “incorrect inference about external reality” - ‘Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, International Version ‘(DSM-IV) p. 783.
One of the most recent of these studies, published 2006, was entitled ‘Need for Closure, Jumping to Conclusions, and Decisiveness in Delusion-Prone Individuals’, by McKay, Langdon & Coltheart, where ‘need for closure’ refers to a motivated need for certainty, whilst ‘jumping-to-conclusions’ bias refers to the gathering of minimal data when making overconfident probabilistic judgements; both of these constructs have been associated independently with delusion-proneness.
The methodology involved the use of standard tools, such as the Peters et al Delusion Inventory, the Huq et al experimental beads task, the Milgram and Tenne scales of decisional procrastination, and the Kruglanski et al. need for closure scale, amongst others.
Whilst it was the view of some earlier researchers that the need for closure motivates a jumping-to-conclusions bias, leading, in turn, to delusion-proneness, no study to date has provided evidence of a direct relationship between greater need for closure and jumping to conclusions.
The findings of this study were that the various facets of need for closure proved to be independent; e.g. intolerance of ambiguity correlated positively with delusion-proneness, whilst decisiveness correlated negatively. The finding that delusion-prone individuals are more indecisive in everyday life was replicated using different scales. Delusion proneness is associated independently with jumping-to-conclusions bias on experimental reasoning tasks, intolerance of ambiguity, and indecision concerning real-life dilemmas.
The results indicated that the jumping-to-conclusions bias may be associated more specifically with a propensity to hold implausible beliefs with unwarranted conviction. Results also indicated that need for closure (NFC) is not a unitary construct in relation to delusion-proneness, i.e. NFC intolerance of ambiguity and NFC decisiveness dissociated, whereas intolerance of ambiguity correlated positively with all aspects of delusion-proneness, decisiveness correlated negatively. However the researchers noted here that it was primarily heightened distress concerning implausible thoughts that predicted indecision concerning real-world dilemmas, as assessed using the NFC decisiveness scales. Furthermore, in the case of implausible ideas that come to consciousness as self-generated notions, these might also be associated with an inappropriate sense of heightened salience, leading to the unwarranted sense of conviction. This suggest that delusional and delusion-prone people express unwarranted conviction in their implausible ideas and jump to conclusions on an reasoning task because they attach inappropriate heightened salience to whatever presents to consciousness as an internally generated first-person representation of reality,
The conclusion is that these results suggest that, if anything, delusion-proneness, or at least delusional distress, is associated with indecisiveness concerning real-life dilemmas. They also suggest that delusion-prone individuals attach an inappropriate heightened salience to whatever presents to immediate consciousness as an internally generated (first-person) representation of reality. The authors of this paper draw on the findings of previous researchers which suggest that it might be this inappropriate salience that then causes the unwarranted conviction in implausible ideas, the jumping-to conclusions bias on an experimental probabilistic reasoning task, and the intolerance of ambiguity and indecisiveness concerning real-life dilemmas that they found in relation to delusion-proneness.
Whilst this abstract does not do justice to a fine highly technical paper, it is interesting to see how many of these summarized conclusions apply to so-called religious beliefs. If the so-called belief in god is not a motivated need for certainty, and their claims that this god is the’ first cause’ is not the making of overconfident judgements on minimal data, or the fact that believers claim that the rules for living a decent life come from their god indicate that they are unable to act decisively for themselves, and that their whole faith is not the result of their delusions, then what is the cause of it?
Perhaps someone will be good enough to offer an intelligent answer that stands up to critical scrutiny to the following question:
“Why do so-called ‘people of faith’ claim to believe in a god?”