We are wired to be prejudiced and a bit racist - but our instinct for collaboration can trump our worst instincts

Fighting your prejudices Chico Sanchez/Getty

FROM Brexit to President Trump, recent political events have let some nasty cats out of the bag. Racists and xenophobes are on the march. But perhaps that shouldn’t be so surprising: after all, that is what we are.

Here’s the unpalatable truth: we are biased, prejudiced and quite possibly a little bit racist. Psychologists have long known that we put people into little mental boxes marked “us” and “them”. We implicitly like, respect and trust people who are the most similar to us, and feel uncomfortable around everybody else. And before you deny it, this tendency towards in-group favouritism is so ingrained we often don’t realise we are doing it. It is an evolutionary hangover affecting how the human brain responds to people it perceives as different.

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In one study from 2000, just showing participants brief flashes of faces of people of a different race was enough to activate the amygdala, part of the brain’s fear circuitry, even though the participants felt no conscious fear. According to more recent research, however, the amygdala doesn’t just control fear; it responds to many things, calling on other brain areas to pay attention. So although we’re not automatically scared of people different from us, we are hardwired to flag them. Evolutionarily, that makes sense: it paid to notice when someone from another tribe dropped by.

We’re also prone to dehumanisation. When Susan Fiske at Princeton University scanned volunteers’ brains as they looked …