Polyvagal theory proposed that an autonomous nervous system imbalance might be characteristic of violent individuals, especially reduced parasympathetic or vagal tone. Accordingly, some studies concluded that when intimate partner violence (IPV) perpetrators deal with acute stress, they tend to present a sympathetic predominance over the parasympathetic nervous system once the stress has ended. However, less is known about cognitive mechanisms that explain this phenomenon. In fact, this functioning might be explained by inner speech and/or angry thoughts (anger rumination) in reactive aggressors. Nonetheless, there is a gap in the scientific literature assessing whether this psychophysiological functioning in IPV perpetrators is explained by anger rumination. For this reason, the first aim of this study was to assess the cardiorespiratory (heart rate (HR), pre-ejection period (PEP), and respiratory sinus arrhythmia (RSA)) and electrodermal (skin conductance level (SCL)) changes, as well as the anger state, when coping with an acute laboratory stressor, comparing a group of reactive IPV perpetrators (n = 47) and a group of non-violent men (n = 36). The second aim was two-fold. After checking whether the groups differed on their anger rumination and manifestation of aggression (reactive and/or proactive) scores, we studied whether these variables explained psychophysiological and psychological responses to a laboratory task (changes and levels during the recovery period) in each group. Our results demonstrated that, compared to the control group, IPV perpetrators presented lower RSA levels (vagal tone). Even though the groups did not differ on their anger rumination or manifestation of aggression scores (except for proactive aggression), only in the IPV perpetrators, high anger rumination and reactive aggression partly explained the lower vagal tone (RSA levels) and high levels of anger state at post-task. Consequently, this study contributes to understanding the psychobiological basis for violence proneness in IPV perpetrators, making it possible to explore new therapeutic strategies.

The importance of psychopathy for perpetration and maintenance of intimate partner violence (IPV) has been speculated. However, less is known about whether psychopathy would explain a psychophysiological response (cardiorespiratory and electrodermal) of IPV perpetrators dealing with acute stressors. Therefore, we first aimed to assess whether IPV perpetrators (n = 58) showed differences in psychopathic traits and their psychophysiological response to acute stress compared to nonviolent men (n = 53). Second, we examined in both groups whether psychopathic traits would explain a psychophysiological response when dealing with acute laboratory stress. Our results revealed that IPV perpetrators differed from controls in all the psychopathic traits, scoring higher on all psychopathy scales. Moreover, IPV perpetrators showed lower total respiratory sinus arrhythmia (RSA) levels than controls. Finally, regarding high total psychopathy scores, factor 1 and affective facet entailed low RSA levels in both groups and scoring high in lifestyle facet of factor 2 explained reduced heart rate (HR) changes in response to acute stress in both groups. All these results highlighted that a reduced vagal tone could be characteristic of psychopathic traits, especially for the affective facet of psychopathy. Therefore, it would be important to incorporate biological markers in combination with psychological measurements to clearly diagnose IPV perpetrators before starting intervention programs. This would increase our ability to improve IPV intervention therapeutic targets and reduce risk of recidivism.