A laboratory task to assess epistemic mistrust: behavioral evidence for mediation between childhood trauma and borderline personality features in young adults.

backgroundDisruptions in epistemic trust have been recognised as key sequelae of trauma and as markers of vulnerability to borderline personality pathology. However, prior research has relied primarily on self-reports and lacks behavioural measures of epistemic stance. The present pre-registered studies introduce a novel behavioural task-the Balloon Analogue Risk Task for Epistemic Trust (BART-ET)-and examine its associations with borderline personality features, trauma history, and psychological distress.

methodsTwo cross-sectional studies were conducted with a combined sample of 273 young adults aged 18-25 (Study 1: N = 120; Study 2: N = 153). Participants completed self-report measures of borderline personality features (PAI-BOR) and epistemic trust, mistrust, and credulity (ETMCQ). Study 2 additionally included the Childhood Trauma Questionnaire (CTQ) and the Brief Symptom Inventory (BSI-GSI). All participants completed the BART-ET in a laboratory setting, which operationalised epistemic mistrust as the degree of deviation from a confederate experimenter's advice during a risk-taking task. Analyses involved correlational tests and structural equation modelling (SEM) to evaluate hypothesised associations and mediation pathways.

resultsAs expected, across both studies, higher levels of borderline personality traits were associated with greater epistemic mistrust-both behaviourally (on the BART-ET) and via self-report (ETMCQ)-and with greater epistemic credulity, but not with epistemic trust, as measured with the ETMCQ. Behavioural and self-report measures of mistrust were significantly correlated, suggesting convergent validity of the BART-ET as an index of epistemic mistrust. In Study 2, childhood trauma exposure was associated with borderline features and with epistemic mistrust assessed behaviourally and via self-report. Preregistered mediation models controlling for general distress (BSI-GSI) suggested that the association between childhood trauma and epistemic mistrust was not unique to BPD features.

conclusionsThese findings suggest that epistemic mistrust-rather than a simple absence of trust-is a social-cognitive correlate of borderline personality vulnerability and trauma exposure in young adults. The results also indicate that the BART-ET may be a useful behavioural tool for studying epistemic mistrust in clinical contexts, though further validation is needed.