Vagal Reactivity and Compassionate Responses to the Suffering of Others
Theoretical and empirical work suggest that the vagus nerve supports social behavior, promoting communication, social engagement, coping or self-soothing in social situations, and the initiation of socially supportive behavior (e.g. Porges, 2003). Guided by this thinking, I predict that the experience of compassion in response to the suffering of others is associated with greater vagus nerve activation. I test this hypothesis across four studies in which participants witnessed others suffer while I recorded physiological measures including a non-invasive index of vagal activity called respiratory sinus arrhythmia (RSA), heart rate, respiration, and skin conductance. Participants exhibited greater RSA activity during the compassion induction compared to a neutral control (Study 1), another positive emotion (Study 2), and a prosocial emotion that lacked the presence of suffering (Study 3). Increases in RSA activity during the experience of compassion were accompanied by decreases in heart rate and occasionally by increases in respiration, but not changes in skin conductance. In Study 4, RSA activity during the compassion induction correlated positively with continuous self-reports of compassion and perceptions of participants' compassion by coders. This work suggests that compassion engages the vagus nerve, facilitating this prosocial response to others' suffering.