Interactive effects of social adversity and respiratory sinus arrhythmia activity on reactive and proactive aggression.

Abnormal parasympathetic nervous system (PNS)-related cardiac activity has been linked to aggression. However, little is known about how it interacts with psychosocial adversity in predisposing to reactive-proactive aggression. In the current study, 84 male and female college students self-reported reactive and proactive aggression, and were assessed for respiratory sinus arrhythmia (RSA), a measure of PNS-related cardiac activity, during rest and when they contemplated an emotion-evoking decision-making task. Regression analyses showed that (a) resting RSA was positively linked to reactive aggression in conditions of high social adversity, and (b) RSA reactivity was positively associated with reactive but negatively associated with proactive aggression, in conditions of low social adversity. Main effects were not found for psychophysiological functioning or psychosocial adversity, suggesting the importance of their interaction. Findings support a biosocial basis for aggression and add additional support for the distinctions between reactive and proactive aggression.