Brain-Behavior Relationships: A Neurobiological Model of Group Hate

Hate toward people groups is a significant cause of human suffering, yet we understand relatively little about its neurocognitive and neuroanatomical bases. While definitions of hate vary, most agree that it can be defined as an aversion to certain others that motivates attempts to expel them through methods ranging from physical violence to passive avoidance. The evolutionary roots of group hate are in the ingroup-outgroup distinction, in which the individual favors ingroup members over outgroup members. Earlier studies on the effects of hate speech and propaganda show that the dehumanization of outgroup members facilitates hate. Although several mechanisms have been proposed, evidence suggests that dehumanization leads to hate due to the perceived failure of outgroup members to meet a moral ideal of right and wrong. As such, hate can be understood as an innate moral sentiment that enhances themes of ingroup loyalty and purity by expelling the offending outgroup. It involves regions of the brain active in social cognition, emotion, empathy, and behavioral regulation, such as the medial prefrontal cortex, inferior frontal gyrus, anterior cingulate cortex, amygdala, insula, and temporoparietal junction. By examining these neurobiological aspects of hate and understanding them in the context of the social and cultural factors that foster hate, we can gain deeper insights into this harmful phenomenon and how best to combat it.