If cycles of division are inherited, they can also be unlearned. The science and history show us: we are not born with enemies.
We are not born hating. No infant enters the world with prejudice encoded in their DNA. The amygdala's threat response, the prefrontal cortex's categorization these are neural tools, not destiny. What we know from decades of social neuroscience is that the brain's bias systems are shaped by exposure, culture, and experience. They can be reshaped the same way.
The landmark research of David Amodio and Mina Cikara at NYU has mapped how the brain distinguishes "us" from "them" in milliseconds faster than conscious thought. The amygdala activates. The medial prefrontal cortex categorizes. Empathy circuits respond more strongly to in-group suffering than out-group suffering. Cikara's 2011 study showed that people actually showed reward-related neural activity when witnessing harm to out-group members. These findings are uncomfortable. They reveal the machinery of division operating beneath our awareness.
But here is the truth the same research reveals: these patterns are learned associations, not fixed traits. The brain's bias circuits change with new information, new relationships, new contexts. Amodio and Devine (2006) demonstrated that implicit bias and explicit stereotyping are independent systems you can hold conscious egalitarian values while unconscious associations persist, but those unconscious associations weaken when you build genuine relationships across difference.
Gordon Allport understood this in 1954. His contact hypothesis that bringing groups together under conditions of equal status, common goals, cooperation, and institutional support reduces prejudice. Pettigrew and Tropp's 2006 meta-analysis of 515 studies confirmed it: intergroup contact reliably reduces prejudice. Even more striking: contact works even when Allport's optimal conditions aren't fully met. Merely having friends across group lines predicts significantly lower prejudice. The brain learns from relationship.
The implications are profound. If the cycles of division are learned passed down through families, reinforced by media, embedded in institutions then they can be unlearned. Not by shaming, not by forcing, but by creating the conditions where the brain can form new associations. Where "them" can become "us."
Key Research:
Allport, G.W. (1954). The Nature of Prejudice. Addison-Wesley.
Amodio, D.M. (2014). The neuroscience of prejudice and stereotyping. Nature Reviews Neuroscience, 15, 670–682.
Pettigrew, T.F. & Tropp, L.R. (2006). A meta-analytic test of intergroup contact theory. Journal of Personality and Social Psychology, 90(5), 751–783.
Cikara, M. et al. (2011). Us versus them: Social identity shapes neural responses to intergroup competition and harm. Psychological Science, 22, 306–313.
Ratner, K.G. & Amodio, D.M. (2013). Seeing 'us versus them': minimal group effects on the neural encoding of faces. J. Exp. Soc. Psychol., 49, 298–301.
Amodio, D.M. & Cikara, M. (2021). The Social Neuroscience of Prejudice. Annual Review of Psychology.
The brain's bias is automatic, but not final. The next time you feel a flash of us-versus-them, you can pause. That split second of pause that's the prefrontal cortex overriding the amygdala. That's the practice of unlearning. You don't have to be perfect. You just have to stay in the room with people who are different from you. The science says that's enough to start.
What Can I Do? Next: Roots of Renewal