The Dark Tetrad, Intimate Partner Violence and the Mediating Role of Moral Disengagement

Purpose: Research suggests that physical, psychological, and/or sexual focussed Intimate Partner Violence (IPV) is related to the dark triad (DT) traits of Machiavellianism, psychopathy, and narcissism. This study extends these findings by considering the addition of everyday sadism into the four-dimension dark tetrad (DTET), testing the possibility that moral disengagement (MD) mediates the relationship between these variables. It was also examined whether the DTET provided incremental validity to the more general personality traits Honesty-Humility, Emotionality, Extraversion, Agreeableness, Conscientiousness, Openness (HEXACO) to predict IPV. Method: Males and females (N = 416) from the general population completed five questionnaires in an online survey (HEXACO-60, MMEA, PMDS, CTS2S, SD4). Results: A principal component factor-analysis found that sexual IPV did not load as an individual factor and distinct form of violence on the CTS2S scale so was excluded from this study. Four hierarchical multiple regressions were conducted, using the demographics, HEXACO and either the DTET traits or an overall DTET variable as predictor variables, and either physical or psychological IPV as the dependent variables. Only psychopathy predicted physical and psychological IPV; MD mediated the relationship between psychopathy and psychological IPV. Although the DTET added incremental validity over HEXACO to predict physical IPV, HEXACO low Agreeableness was the strongest predictor of psychological IPV. Conclusions: Those higher in psychopathy may show different offending trajectories for physical and psychological IPV dependent upon the use of MD processes. Despite the DTET adding incremental validity over the HEXACO dimensions, some HEXACO elements better explain the relationship between personality and psychological IPV than the DTET.