Conspiracy endorsement is a public health challenge for the successful containment of the COVID-19 pandemic. While usually considered a societal phenomenon, little is known about the equally important developmental backdrops and personality characteristics like mistrust that render an individual prone to conspiracy endorsement. There is a growing body of evidence implying a detrimental role of adverse childhood experiences (ACEs) – a highly prevalent developmental burden – in the development of epistemic trust and personality functioning. This study aimed to investigate the association between ACEs and conspiracy endorsement in the general population, specifically questioning a mediating role of epistemic trust and personality functioning.

Based on cross-sectional data from a representative German survey collected during the COVID-19 pandemic (N = 2501), we conducted structural equation modelling (SEM) where personality functioning (OPD-SQS) and epistemic trust (ETMCQ) were included as mediators of the association between ACEs and conspiracy endorsement. Bootstrapped confidence intervals (5000 samples, 95%-CI) are presented for all paths.

ACEs were significantly associated with conspiracy endorsement (β = 0.25, p < 0.001) and explained 6% of its variance. Adding epistemic trust and personality functioning as mediators increased the explained variance of conspiracy endorsement to 19% while the direct association between ACEs and conspiracy endorsement was diminished (β = 0.12, p < 0.001), indicating an indirect effect of personality functioning and epistemic trust in the association between ACEs and conspiracy endorsement. Fit indices confirmed good model fit.

Establishing an association between ACEs and conspiracy endorsement further increases the evidence for early childhood adversities' far-reaching and detrimental effects. By including epistemic trust and personality functioning, these findings contribute to a deeper understanding of the underlying mechanisms in the way that ACEs may be associated with conspiracy endorsement.