Hate Trump supporters? Hate liberals? Here's why

Deep in the brain, your amygdala generates a knee-jerk response to political enemies and other threats. But experiments show the divide can be bridged

Anti-Trump protesters as clash with supporters of the Republican presidential candidate in San Diego, California. on 27 May 2016.
Anti-Trump protesters as clash with supporters of the Republican presidential candidate in San Diego, California, on 27 May 2016. Photograph: Mark Ralston/AFP/Getty Images

I was walking back to my room on the ninth floor of a hotel in Kuala Lumpur last October, and I happened to meet the guy in the room next door, standing in the hall, searching for his key card. We said hi. Clearly we had English in common as a first language (he was American, I’m Canadian).

“It looks like Trump is finally going down,” I said. The election was on everybody’s mind, and Trump’s ratings were sinking that week. The fellow looked at me in a friendly way and said, “Yeah, but he’s still got a chance. There’s still hope.”

I was speechless. My neighbor was a Trump supporter?!

Now, three months later, Trump is in the White House, and many of us wonder how he got there. The liberal consensus is that he got there by activating people’s fears. In fact we hear a lot about the politics of fear. With President Trump in the US and the rise of rightwing candidates in Europe, many believe fear has become kingmaker worldwide. We debate these trends endlessly in the news, on blogs, on Twitter and Facebook. But here I want to go a bit deeper and ask how political ideologies are forged in the brain.

Let’s start with the main act: the human tendency to favour our own kind and fear those who look, act, or speak differently. Psychologists call it social identity theory: we overvalue our own – the in-group – and devalue the other guys – the out-group. Not surprisingly, the brain evolved over aeons of social conflict to entrench these fundamental biases. In particular, the amygdala, that pair of almond-shaped structures on each side of the head, is the brain part that triggers fear, anxiety, and other negative emotions (and some positives too). So how does the amygdala get us to stick to our own kind?

The most prominent in-group/out-group difference is race. People of other races do not appear to be like us, and that bias runs deep. A number of studies over the past two decades show that amygdala activation goes up when we’re shown faces of people of other races, indicating fear, anxiety, or possibly contempt. This reaction takes place so fast that it precedes reflection and judgment – in fact consciousness itself. So, OK, we tend to disdain out-group members because our brain sends us down that path quickly and reliably. That may be where the politics of fear gets its traction.

But it’s not that simple.

My favourite study of racism and the brain was published by Wil Cunningham, a colleague from the University of Toronto. He exposed white participants to pictures of black and white faces, and he measured the activation of two distinct brain regions, the amygdala and the prefrontal cortex. While the amygdala triggers rapid feelings, the prefrontal cortex allows us to think, self-regulate, and make rational judgments. Each of these regions tells a different story about how we react to the other guys.

When the pictures were flashed for only 3% of a second (a sliver of time preceding consciousness), amygdala activation spiked highest in people with the highest scores on a scale of implicit racism. (They did not know they were being tested for racism.) However, when the faces were left on the screen for half a second (a long stretch of time for the brain), the amygdala response was greatly reduced, the prefrontal response was greatly increased, and the more activity recorded in prefrontal cortex, the greater the reduction in the amygdala response.

So the rapid fearful bias toward other races can’t be ignored, and our neural responses match attitudes we don’t even know we have. But given half a second to consider, we can outmanoeuvre that rapid response. Also fascinating, a previous study published by Phelps and colleagues found the same correlation between amygdala activity and implicit racism, but no correlation whatsoever between amygdala activity and self-reported racial attitudes, arrived at through conscious reflection.

Taking these findings together, it seems that the fearful amygdala reflex can give way to people’s conscious reflections on their own attitudes and the merits of other people.

There are a few implications of this work, some of them ominous, others more optimistic. First, out-group biases run fast and deep. The fact that they’re triggered so quickly means that they can determine our moods, our attitudes, and maybe even our votes, by tipping us into a biased mindset before we think things through.

Second, like any other strong emotional habit, fearful responses to out-group members will self-amplify over time. The amygdala is exquisitely programmable and it learns by association, not rationality. The more you use it, the less likely you are to lose it. That might be good news for those who deliberately promote the politics of fear.

But there’s good news too.

A second phase of the Phelps study tested the same brain processes, this time with faces of familiar and admired black men. This time the amygdala response was no different for white v black faces and there was no correlation between amygdala activity and racism scores. As the authors conclude, cultural values and individual experience can overcome the brain’s racism.

In a study by Van Bavel and colleagues, black and white participants were mixed together and then randomly assigned to two “teams”. Individuals were trained to categorize each other based on team membership and race, thus cultivating team solidarity (a new in-group) without ignoring perceptions of race. The results showed in-group/out-group bias, as expected, both in brain responses and behavioural ratings. But these biases were now solely in relation to the other team, not the other race.

Racism isn’t the only out-group bias. It’s just the most obvious. We also identify other people as being like us or unlike us based on all kinds of features, including their political affiliations. Those Republicans are racist jerks, completely unlike us, say the liberals. Those Democrats won’t even try to protect our country and our people, say the conservatives. So let’s not be too hasty in how we judge the impact of brain-based biases on our opinions and our votes. Nobody is innocent when it comes to deep brain wiring.

Yet, whether we’re considering race or party affiliations, reconciliation can win out over bias. Given that we can activate prefrontal judgment to overpower our biases, and given that social experience can so easily outpace race-based feelings, we should acknowledge that biases aren’t carved in stone.

There might be many ways to increase our reflective capacities. (For example, cognitive exercises are known to increase cortical plasticity.) But familiarity with “the other guy” is the most natural defense against blind suspicion. I should have had a drink with my ninth-floor neighbour – the hotel bar was still open – instead of closing my door and pulling my hair out. Maybe we’d have found something in common.