Reasons to believe: A systematic review and meta-analytic synthesis of the motives associated with conspiracy beliefs.

Belief in conspiracy theories has been linked to harmful consequences for individuals and societies. In an effort to understand and mitigate these effects, researchers have sought to explain the psychological appeal of conspiracy theories. This article presents a wide-ranging systematic review and meta-analysis of the literature on conspiracy beliefs. We analyzed 971 effect sizes from 279 independent studies (N_participants = 137,406) to examine the relationships between psychological motives and conspiracy beliefs. Results indicated that these relationships were significant for all three analyzed classes of motivation: epistemic (k = 114, r = .14), existential (k = 121, r = .16), and social motivations related to the individual, relational, and collective selves (k = 100, r = .16). For all motives examined, we observed considerable heterogeneity. Moderation analyses suggest that the relationships were weaker, albeit still significant, when experimental (vs. correlational) designs were used, and differed depending on the conspiracy measure used. We statistically compare the absolute meta-analytic effect size magnitudes against each other and discuss limitations and future avenues for research, including interventions to reduce susceptibility to conspiracy theories. (PsycInfo Database Record (c) 2025 APA, all rights reserved).