The biology of hatred: Why love turns to hatred and what we can do about it

Ancient texts warn us that love can quickly turn into hatred. We hear of Cain and Abel, Medea murder of her children, and “Et tu, Brute?” still rings the bitter sound of friendship turned betrayal. In this talk, I'll present our theoretical perspective on the neurobiology of hatred that is based on our model on the biology of human love and its three foundations; the oxytocin system, the attachment network in the brain, and biobehavioral synchrony, the process by which humans create a coupled biology through coordinated action. All three mature in mammals in the context of the mother-infant bonding and then transfer to enable life within social groups. During the transition from intimate bonds to social group living, they partition to support love and solidarity to one's group and fear and hatred toward the out-group based on minor variations in social behavior. On the basis of this model, we built the Tools of Dialogue© intervention for outgroup members and applied it to Israeli and Palestinian youth using a randomized controlled trial (RCT).  Before and after the 8-session intervention, we measured social behavior, political attitudes, hormones, and social brain functioning. Following the intervention, youth increased behavioral reciprocity and reduced hostile behavior during one-on-one interaction with outgroup, attenuated the neural marker of prejudice and increased their neural empathic response, reduced cortisol and elevated oxytocin, and adapted attitudes of compromise.  These neural changes shaped their peacebuilding activity 7 years later, when they were young adults who can assume political and civic responsibilities.  Our findings, the first to show long-term impact on brain of an intergroup intervention, show how social synchrony can tilt the neurobiology of hatred toward the pole of reciprocity and compromise.