Summary: “When choosing whether to act altruistically, people may compare the current option to an idiosyncratic ideal. Prosocial individuals seem to represent deviations from that ideal in the amygdala, but selfish individuals do not. Oxytocin administration makes selfish individuals look more like prosocial individuals, behaviorally and neurally….”
Roberts ID, Teoh YY, Hutcherson CA: Oxytocin and the altruistic ‘Goldilocks zone’, Nature Neurosci. 22(4): 510-512 (2019).