Rationale:
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.

Methods:
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.

Results:
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.

Conclusions:
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.