Child and parent behavioral and physiological reactivity to threat and distress predict children's proactive and reactive aggression.

Introduction: Threat reactivity has been linked to early manifestations of aggressive behavior, with prior research suggesting that parenting can moderate the relation between a child's psychophysiological reactivity and antisocial behavior. However, to date, few studies have examined both parents and children's bio-behavioral reactivity to emotional stimuli, and how their interaction can influence children's aggressive behavior. The present study investigated how parents' sensory processing sensitivity and heart rate (HR) reactivity to distress moderated the association between children's HR reactivity to threat, fearlessness and callous unemotional traits with reactive and proactive functions of aggression. Method: The sample consisted of 124 parent-child dyads recruited from a nationwide study on antisocial behavior. Results: Results indicate that the child's callous unemotional traits and parents' sensory processing sensitivity increase the likelihood of both reactive and proactive aggression. In contrast, the child's fearlessness mainly predicted reactive aggression. In addition, an interaction effect suggested that the child's HR reactivity to threat was negatively associated with proactive aggression when parental HR reactivity to others' distress was low, but positively associated with proactive aggression when parents' reactivity to distress was high. Discussion: Findings provide evidence for the importance of investigating physiological concordance and can inform developmental psychopathology models of antisocial behavior.