A key component of revenge: The “love” hormone
Association of brain networks mediates propensity for revenge. A study of intergroup conflict in humans reveals stronger activation of the medial prefrontal cortex and higher levels of oxytocin increase the tendency to retaliate against out-group members.
Emotional contagion highly mediates humans’ emotional experiences, this is to say that people are affected by the transmission of someone else’s emotions (Thornton and Tamir 2017). Although this mechanism of contagion helps to socially interact, it can be detrimental to society when it involves the transmission of anger (Qu et al. 2016). The concept of people belonging to an ingroup (identified by the same characteristics) than to an outgroup (differing in identity) intensifies these emotions. Moreover, along with enhancing emotions, the tendency of revenge towards the other group as a response to their offenses is consequently strengthened (Pereira and van Prooijen 2018).
The neurobiological responses to intergroup conflict still haven't been completely understood, nor the neural mechanism that drives revenge desire. Due to its worldwide relevance, of social dynamics and conflict, revenge propensity’s neurobiological mechanism needs to be understood. In their paper published in eLife, “A neurobiological association of revenge propensity during intergroup conflict”, Han et al. (2020) demonstrated that humans had a higher propensity to harm everyone outside their ingroup when their levels of endogenous oxytocin (OT) were elevated and mediated by the medial prefrontal cortex (mPFC) as a response of an outgroup member inflicting pain on an ingroup person. This association of the mPFC, OT, and revenge could potentially explain the neural underpinning that promotes the process of conflict contagion.