Our brains are programmed to distrust outsiders. But are we hard-wired to hate?

Those early humans who acquired an unconscious, instantaneous way to recognise and classify strangers – and to treat them with great suspicion, or worse – were more likely to live and reproduce. Their children inherited this instinct and it spread throughout early human populations. Their evolving brains learnt to automatically classify people as either "one of us" or "one of them".

Studies suggest that our brains still have this protective programming – a psychological need to divide people into groups. Unfortunately, one of the most pernicious examples of this inborn trait, and certainly among the most persistent, is racism. Might we be programmed from birth to hate people with a different skin colour? Scientists today are working hard to solve this mystery and they are coming up with some startling new answers to these questions: why and whom do we hate? While our need to categorise people is inherited, it seems, we may be more innately colour-blind than was previously thought.

That may seem like a surprising finding, given the colour-conscious society we live in. In 21st century America, most people still view one another through the prism of race. Skin colour often determines who’s a member of our religious group, our neighbourhood, our office clique, our school or social club – and who isn’t.

The stubborn persistence of racism in modern culture has led social scientists, neurobiologists and evolutionary psychologists to take a hard look at why – with all the differences between humans we could choose to focus on – the human mind seemingly insists on classifying others primarily by race and specifically as white, black or Asian, as studies find. One of those scientists was Mahzarin Banaji, now an experimental psychologist at Harvard, who in the late 1990s, with Anthony Greenwald of the University of Washington, developed the Implicit Association Test, which attempts to lift the curtain on people’s unconscious attitudes and feelings about race.

The premise of the experiment is that unconscious stereotypes operate without deliberate thought but can powerfully affect behaviour, preferences and judgements. The test (try it online) measures how quickly people associate positive or negative words ("glorious", "evil", "failure", "love") with a photo of a black face or a white one. The more automatically your mind links "horrible" to a black face or "love" to a white one, the faster you press a key. If the task requires you to quickly link "failure" to a white face and your mind rebels, your responses will be slower.

In the years since Banaji and Greenwald crafted this test, the findings have held steady. About seven out of 10 white people show unconscious racial prejudice, including those who claim to be bias-free. The test has shown that many Americans – especially white and Asian – "have an automatic preference for white over black", as the scientists put it. How automatic? Even an ethnic-sounding name can elicit prejudice. "It is surprisingly easy to get people to develop a false memory that a person named Tyrone is a criminal," Banaji says.

In subsequent experiments, however, Banaji found that if our tendency to group people is automatic, it’s also highly emotional. Peering inside the grey matter of her subjects, Banaji discovered that when shown photos of black faces, whites who showed unconscious prejudice on the Implicit Association Test had increased activity in the amygdalae, a pair of little almond-shaped structures deep in the brain that register fear and anger. Interestingly, the subjects didn’t have this negative reaction when they viewed faces of well-liked black Americans, such as Bill Cosby. Their brain activity was revealing the effect of cultural learning, Banaji suspects.

While these negative emotional responses were deeply rooted in the brain, they may not be indelible. "It is only due to the memory of recent historical events that the groups we ‘naturally’ see are black and white," argues Michael Shermer, whose new book The Science of Good and Evil explores the biological and evolutionary roots of morality and ethical systems. He believes that the racism detected by Banaji’s tests reflects something our minds have learnt, not something our brains were hard-wired with at birth. There is no reason classification has to be based on skin colour, Shermer notes. Instead, the brain should seize on any characteristic, any marker that could indicate a distinction between one group and another. "If everyone looked like Tiger Woods," says Shermer, "we’d simply find other ways to divide people up." Perhaps eyebrow shape would then be the dividing characteristic.

It’s not difficult to find real-life examples that support Shermer’s theory. Northern Ireland’s Catholics hate its Protestants and vice versa. Atrocities between Hutu and Tutsi in Rwanda or Serbs and Albanians in Kosovo didn’t erupt from recognition of racial differences but rather for religious and political reasons.

In fact, people are more likely to automatically classify one another by sex and age than they are by race, says evolutionary psychologist Robert Kurzban of the University of Pennsylvania. Humankind hasn’t been out of Africa long enough, he says, for our brains to evolve the wiring that lets us see race in a way that’s as fundamental as whether someone is, say, a young girl or an old man.

Thus, linking the origins of racism to early humans could be misleading. "These different groups of early humans almost never came into contact with one another, so there would be little opportunity to evolve a classification system that grouped people by race," Kurzban says. Indeed, they may never have encountered someone of a different race. "In prehistoric times, even our enemies looked like us," Kurzban says. "There was no evolutionary pressure for brains to instantly classify people into ‘members of my race’ and ‘the enemy’."

The latest research in human genetics further weakens the case for innate racial bigotry. Standard racial categories as we define them, more geneticists are concluding, have no biological validity. Yes, there are obviously genetic differences between the smaller groupings called biological populations – say, between a member of the Yoruba tribe of Nigeria and a Lapp from northern Scandinavia, for instance. But the genetic differences between racial groups of white, black and Asian are less than the differences within any one of these major groups. This means that you are more genetically similar to many people outside your race than to many of those within it.

Kurzban recently conducted a study that offers convincing evidence that race is not a basic classifying factor. He and colleagues at the University of California, Santa Barbara, had 200 volunteers look at 24 photos of basketball players on a computer screen. Each player pictured belonged to one of two teams that had recently brawled, Kurzban told the volunteers, and they were all wearing identical jerseys. Paired with each photo was a sentence that a particular player had uttered during the rumble. The volunteers’ test: look at all 24 photos and as each sentence was flashed on the screen again, recall who said it.

When the subjects got it wrong, their mistakes were telling. When they attributed a sentence to the wrong player, their incorrect choice was usually a person of the same race as the player who actually said it. It was as if they were thinking, I don’t recall who said it but it was definitely a white guy.

Next, they viewed photos of the same players but each was wearing either a grey or yellow jersey. Once again, the misattributions fell along colour lines – but this time it was the colour of the player’s jersey, not skin. The volunteers had quickly made the mental switch to classifying people by a more logical sign of a group: the colour of their uniforms.

"Despite a lifetime’s experience of race as a predictor of social alliance, less than four minutes of exposure to an alternate social world was enough to deflate the tendency to categorise by race," the scientists concluded. Race can quickly be overridden as a factor if people see a more immediate basis for a coalition, such as the colour of a team jersey. "The human mind is very flexible," Kurzban says. "It dynamically evaluates situations."

So while it appears that we are hard-wired from birth to view the world in terms of "us" versus "them", the evidence shows that we can reprogramme our brains to come up with new definitions for who we view as "us" and who we view as "them". One way to stop our brains from perceiving race as a meaningful way to categorise people is to mimic the conditions of these experiments. Namely, to mix it up at work and play, so "my group" includes people who look different from "me". This has never been easy. But at least we can strive for a society that treats all men and women as equals, knowing there is nothing in the human psyche that makes racism inevitable.

(Sharon Begley is the science columnist of The Wall Street Journal.)

(Courtesy: SPAN magazine.)