A multilevel examination of lifetime aggression: integrating cortical thickness, personality pathology and trauma exposure.

Aggression represents a significant public health concern, causing serious physical and psychological harm. Although many studies have sought to characterize the etiology of aggression, research on the contributions of risk factors that span multiple levels of analysis for explaining aggressive behavior is lacking. To address this gap, we investigated the direct and unique contributions of cortical thickness (level 1), pathological personality traits (level 2) and trauma exposure (level 3) for explaining lifetime physical aggression in a high-risk sample of community adults (N = 129, 47.3% men). First, the frequency of lifetime aggression was inversely associated with cortical thickness in regions of prefrontal and temporal cortices that have been implicated in executive functioning, inhibitory mechanisms and socio-emotional processing. Further, aggression was positively associated with pathological personality traits (antagonism and disinhibition) and exposure to assaultive trauma. Notably, all three levels of analysis (cortical thickness, pathological personality traits and assaultive trauma exposure) explained non-overlapping variance in aggressive behavior when examined simultaneously in integrative models. Together, the findings provide a multilevel assessment of the biopsychosocial factors associated with the frequency of aggression. They also indicate that cortical thickness explains novel variance in these harmful behaviors not captured by well-established personality and environmental risk factors for aggression.