title: Jumping to Conclusions About the Beads Task? A Meta-analysis of Delusional Ideation and Data-Gathering.
abstract: It has been claimed that delusional and delusion-prone individuals have a tendency to gather less data before forming beliefs. Most of the evidence for this "jumping to conclusions" (JTC) bias comes from studies using the "beads task" data-gathering paradigm. However, the evidence for the JTC bias is mixed. We conducted a random-effects meta-analysis of individual participant data from 38 clinical and nonclinical samples (n = 2,237) to investigate the relationship between data gathering in the beads task (using the "draws to decision" measure) and delusional ideation (as indexed by the "Peters et al Delusions Inventory"; PDI). We found that delusional ideation is negatively associated with data gathering (r(s) = -0.10, 95% CI [-0.17, -0.03]) and that there is heterogeneity in the estimated effect sizes (Q-stat P = .03, I(2) = 33). Subgroup analysis revealed that the negative association is present when considering the 23 samples (n = 1,754) from the large general population subgroup alone (r(s) = -0.10, 95% CI [-0.18, -0.02]) but not when considering the 8 samples (n = 262) from the small current delusions subgroup alone (r(s) = -0.12, 95% CI [-0.31, 0.07]). These results provide some provisional support for continuum theories of psychosis and cognitive models that implicate the JTC bias in the formation and maintenance of delusions.
authors.affiliation: ARC Centre of Excellence in Cognition and its Disorders, Macquarie University, Sydney, NSW, Australia; Department of Cognitive Science, Macquarie University, Sydney, NSW, Australia; robross45@yahoo.com.au.
authors.forename: Robert Malcolm
authors.initials: RM
authors.lastname: Ross
authors.affiliation: ARC Centre of Excellence in Cognition and its Disorders, Macquarie University, Sydney, NSW, Australia; Department of Psychology, Royal Holloway, University of London, Egham, Surrey, UK.
authors.forename: Ryan
authors.initials: R
authors.lastname: McKay
authors.affiliation: ARC Centre of Excellence in Cognition and its Disorders, Macquarie University, Sydney, NSW, Australia; Department of Cognitive Science, Macquarie University, Sydney, NSW, Australia;
authors.forename: Max
authors.initials: M
authors.lastname: Coltheart
authors.affiliation: ARC Centre of Excellence in Cognition and its Disorders, Macquarie University, Sydney, NSW, Australia; Department of Cognitive Science, Macquarie University, Sydney, NSW, Australia;
authors.forename: Robyn
authors.initials: R
authors.lastname: Langdon
mesh_terms: D000328:Adult; D003702:Delusions / Q000503:physiopathology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011618:Psychotic Disorders / Q000503:physiopathology*; D013850:Thinking / Q000502:physiology*; D055815:Young Adult
keywords: beads task; bias; delusion; jumping to conclusions; meta-analysis; schizophrenia