Psychophysiological underpinnings of proactive and reactive aggression in young men and women.

Reactive aggression is posited to occur as a result of hypersensitivity to threat, whereas fearlessness may drive proactive aggression. This study aimed to test if physiological fear reactivity differentially relates to self-report reactive and proactive aggression using immersive virtual reality fear (VR) induction. We collected subjective fear ratings and sympathetic (SNS; skin conductance) and parasympathetic (PNS; respiratory sinus arrhythmia) nervous system reactivity during an interactive VR horror video. Results showed that for men and women, reactive aggression was related to heightened SNS fear reactivity. For men, proactive aggression was related to hypoarousal of the PNS and SNS (coinhibition) during fear induction, whereas augmented PNS was related to proactive aggression in women. These results support the fearlessness hypothesis for proactive aggression in men, but this does not replicate in women. By contrast, hypersensitivity to fear is related to reactive aggression for both men and women.