“That's Our Biggest Difference”

Us and Them: Understanding Your Tribal Mind
by David Berreby

There are so many ways to sort people. We all do it, all the time. From everyday decisions (whom to invite to dinner?) to life choices (whom to marry?) to the great turning points of history (whom to war against?), we're guided by an ever-present sense, in any situation, of who belongs with whom, and what that belonging means. Everyone is part of many groups at once, of course-you might be a woman, a parent, a Republican, an American, and a Hindu. So, how do we decide which identities matter? Why do they matter so much? What makes people willing to die, or to kill, for a religion, nation, race, or caste?

In this groundbreaking book, David Berreby shows how science tackles these questions of group identity. Drawing on new findings from anthropology to neuroscience, he argues that this 'tribal' sense is a part of human nature, expressing itself in every aspect of life.

The effects run deep, shaping our lives and opportunities. Us and Them elegantly explains how this tribal sense:

• Alters our thoughts. Show older people a negative image of the aged, and they act more feeble. Asian women reminded of their Asian heritage did better on a math test than those who were reminded they were women. In a small room, the lone holdout against a group's opinion usually gives in and changes-even when it's obvious that the group is wrong.

• Affects our health. People's sense of their place in society directly links to measures of stress, depression, and cholesterol levels.

• Affects our society more than we realize, because it can be manipulated for good and for ill. Tribal rhetoric has made people feel that injustice and oppression are perfectly normal, for instance, while at other times, it has led them to set aside hatred in favor of reconciliation. One experimenter made a group of young summer campers into warring 'tribes.' And, just as easily, he brought them back together. Us and Them explains how and why the tribal 'buttons' are pushed.

We can't live without our tribal sense. It tells us who we are and how we should behave. It frees us from the narrow confines of the self, linking us to others and the past and the future. Some condemn this instinct, as if it were only a source of evil. Others celebrate it, as if loyalty and faith were never misused. David Berreby brilliantly describes a third alternative: how we can accept and understand our inescapable tribal mind.

Chapter 1

All good people agree,
And all good people say,
All nice people, like Us, are We
And every one else is They.

  —Rudyard Kipling, "A Friend of the Family"

Scientists, when they turn their attention to people, usually talk about the entire human race or about the individual human being. Those are two faces of the same idea. Truth about all is truth about each; a theory about the mind or morality applies to everyone who ever lived, as well as to you in particular. Either perspective yields big explanations, which make many predictions to test and suggest many experiments. It's where researchers like to be - working on "the" genome, or "the" brain, or "the" self.

They aren't nearly as comfortable with the categories in between one person and all people - the ones that researchers, like everyone else, use when they're off duty, away from their work. Categories like Americans and Iranians, Muslims and Christians, blacks and whites, men and women, southerners and northerners, doctors and lawyers, gays and straights, soccer moms and NASCAR dads, outgoing people and shy types, smart ones and lucky ones. Those - and all other labels that define more than one person but fewer than all - are what I (following the philosopher Ian Hacking and the psychological anthropologist Lawrence A. Hirschfeld) call "human kinds."

Human kinds, whose memberships fall between All and One, map a much more variegated world than that one-size-fits-all label Homo sapiens. Some human kinds are types, like cranky old men and plumbers. Others are cultures, like Basques and Thais. Some are old and populous, like the category Japanese or Jain; others are small scale and recent, like "former graduate students of Steven Pinker."

Some human kinds even include nonhumans. Your family, for example, might include a dog or a cat for which you feel more and do more than you do for faraway people. And human kinds may also enfold nonliving things-like flags, sacred books, and graves-that are revered and protected as if they too had lives to live and lose.

Human kinds are infinitely divisible: examine one, and you find inside it subcategories and, inside those, still more. For example, military veterans are a distinct kind of person from those who did not serve; Navy vets are distinct from other services; those who served in the brown-shoe navy (its aviation-related services) are distinct from the black-shoe navy (other ships), and among the black-shoe vets submariners are their own tribe, and so on and on. Some human kinds, we are told from a very early age, we were born into-families, races, ethnic groups, religions, and nations. Other kinds are based on bodies: male and female, athletic or disabled. There are other kinds that other people put us into, like nerd or jock, Bible-thumper or Godless secular humanist. There are the kinds we join by passing special tests, like doctor or accountant. And the ones we join to make a living, like pizza guy or copyeditor. There are happenstance human kinds, like "women in the ladies' room on the 8:15 ferry." There are others we sign ourselves into by conviction, like the National Rifle Association or the Democratic Party, and some we join because we think we must to survive- like gangs, militias, and secret societies.

Some human kinds make sense only because members see and depend on each other every day, like the soldiers in a combat unit. Others consist of people who never meet, like the millions of fellow citizens those soldiers defend. In other words, human kinds serve so many different needs, there is no single recipe for making one. Parentage makes a person a Brahmin, training makes her a soldier, sending in dues makes her a member of a religious congregation. She can convert to Islam, but not to Chineseness; she can marry into Protestantism, not into liberalism.

Why is all this variety possible? That's not a question that can be answered by looking at the political, economic, or cultural aspects of human kinds, as important as those aspects are. The issue is not what human kinds are in the world, but what they are in the mind - not how we tell Tamils and Seventh-Day Adventists and fans of Manchester United from their fellow human beings, but why we want to.

After all, other creatures get along fine without dividing themselves into such tribes. With one important exception, for instance, humanity's close relative the chimpanzee goes through life quite well solving only problems about Everychimp and problems about My Friend and Cousin, the one with the long face and the limp - chimps in general and individuals. Yet a human who went through life like that would not know what "our kind" of food is, or enjoy "our kind" of music, or know what "we do" when someone dies.

Such a person, lacking any sense of family tradition, religious history, patriotism, or cultural pride, would not live a fully human life. Human-kind thinking is an absolute requirement for being human.

Which brings up the dark side: people are killed for nothing more than their membership in the "wrong" tribes. Many times in the past few years, young men who were polite and thoughtful to members of their own sort, who loved their mothers and listened to their fathers and cared for their children, set out to kill other people's mothers and fathers and children without a qualm - in New York City on September 11, 2001; in Beslan, Russia, on September 1, 2004; in Nazi-ruled Europe in the 1930s and 1940s. More examples could fill every page of this book. Throughout history, killers have worked with zeal because they believed their victims were not of the same kind as the people they cared about, the people who mattered. No wonder people both cherish and fear the power of tribal thinking. No wonder they want to understand it.

Many people today find themselves struggling, again and again, with a difficult question: Who is "our side"? In the days after the September 11 attacks, the prime minister of Italy spoke of the superiority of Christian civilization and was immediately denounced by his allies; two religious leaders in the United States tried to claim that abortionists and civil libertarians did not belong in the new alliance against terror because they made God angry. The president of the United States, though he was a political ally, rebuked the clergymen. The new antiterror coalition of nations could not make war on Islam because they had millions of Muslim citizens. Was it, then, a coalition of democracies? The most important frontline ally in the ensuing war was Pakistan, a dictatorship. Obviously, sides in the current conflict were chosen; they aren't a matter of "natural" or inevitable divisions. Today it is clear as never before that human kinds - those categories we use to explain human acts on every scale, from a morning walk ("Why were those men wearing turbans?") to all of history ("Is war inevitable?") - don't depend on what people are, but on what people believe.

That's the difference between human tribes and the boundaries animals observe. Many creatures, from mice and pigeons to lions and dolphins, know a member of "our group" from a stranger. All these creatures have been well studied in the past few decades, and the pattern is clear: fights within the group are limited and tend not to get out of hand, but fights between groups end in deaths. This in-group restraint, as the psychiatrist and author Jonathan Shay has said, gave rise to the widely believed myth that animals don't kill their own kind. In fact many animals - lions, gorillas, chimpanzees, hyenas - are happy to kill their own. The victim just can't be a member of their little band.

Animals, though, don't make decisions about who is "in" and who is "out." A dog guards her puppies because they are kin, and members of her human family because they are friends. But no dog quits her humans because they have converted to Catholicism or put a peace sign on the lawn.

People can and will make that sort of change, because people, unlike animals, make choices based on signs-crosses, uniforms, peace signs, oaths, and other indicators of a particular human kind. Animals have kin and animals have friends, but only human beings trust symbols to tell who is kin and who is a friend.

One August night in New York City in 1997, for example, the crucial symbol was a tiny piece of metal. A white cop beat up a black man he had arrested. Later, both men were in the bathroom of the police station, where the officer spotted a tiny crucifix that his victim wore around his neck. That was enough to make the cop put away one map of human kinds and take up another - instead of police against suspect, or white against black, he now saw two fellow Christians. The officer said he too believed in Jesus, and apologized.

In Sovu, Rwanda, on May 6, 1994, the symbol was a bit of cloth. That day, Tutsi refugees sought escape from bands of Hutus in Sovu's convent. The mother superior, Sister Gertrude, called in the Hutu militia. Hundreds of the Tutsi were shot, hacked, or burned to death. But Sister Gertrude did not turn over the convent's Tutsi nuns. Their veils protected them. Seeing this, a nineteen-year-old woman named Aline, the niece of a nun, begged for a veil. Sister Gertrude refused.

Seven years later, she was convicted in Belgium of war crimes. Among the witnesses was the murdered niece's mother. "My daughter was killed because of a little piece of cloth," she said. If humans are, as the neuroscientist Terence Deacon puts it, the "symbolic species," then human kinds are among those features that reveal our uniqueness. A symbolic strip of cloth - its presence saving you from a pack of rampaging killers, its absence marking you as the kind to kill - is something only Homo sapiens creates.

But a symbol, like that nun's veil, is meaningless unless it is understood. If the murderers had thought it was just a bit of cloth, for example, they would have killed all the Tutsi who wore it. Any activity that depends on symbols can't be understood without taking into account the human minds that use those symbols. Imagine trying to get by in Kinyarwanda, the language shared by Hutu and Tutsi, by treating it only as a system of sounds - wavelengths and acoustic properties. You wouldn't get far until you accepted that these sounds meant something, and found someone to explain what those meanings were.

In the same way, human kinds can't be understood objectively, as a collection of facts about blood types, skull shapes, average ages, preferred brands, and so on. Those facts seen from the outside can never tell what the human kind means. That meaning is made inside the heads of people who believe in it.

Scientists who study a pack of macaque monkeys can predict who gets along with whom. Knowing which animals are relatives and which are allies lets an observer explain the fights and frolics very well. But "objective" knowledge of human kinds does not. Sister Gertrude was a Hutu, so you would not be surprised if she had sent all the Tutsi in the convent to death. Yet she was also a nun, so it's not a surprise that she saved fellow nuns even though they were Tutsi. She was also a Christian; it would be admirable and understandable if she had stood, on religious principles, against the killing of any human being.

The important point is that any of these alternatives is possible. Mindless facts - who is a Tutsi, who is a Hutu, who has a veil, who lacks one - cannot predict what people will do. Human beings are unusually alike, compared to most species. We're also, each of us, unique. From those two facts, it follows that measurable, objective differences will always exist between any two groupings of people, and that any two groups, no matter how different, will be the same on many other measures. It will always be possible to find differences between this race and that one, this nation and those, people with this gene versus people without it. But not one of those facts will tell why you divided people into the human kinds you chose to analyze.

People who look at the traits of the kinds themselves, then, are posing the wrong questions. Do American Jews have higher average scores on certain academic tests than other Americans? Do African American marrieds have sex more often than others? Are Hispanics more likely to attend church? Maybe so, maybe not; but people don't start with data and then divide the world into Jews, African Americans, and Hispanics. It's the other way around. First we believe in those human kinds, and then, because we believe, we gather the data. To understand this aspect of ourselves, we don't need any more facts about human kinds. We need facts about human minds.

One way to find those facts is to study human kinds as if they were rules for thinking-methods of sorting out perceptions. You see a woman caring for her child and class her as a mother; you see a white-haired, stooped man and class him as an old person. That's a psychologist's approach. On the other hand, sociologists and anthropologists have looked at human kinds as rules for behavior-methods of knowing what people are supposed to do. In the right circumstances, knowing that someone is in the navy, or a doctor, or a devout Christian, tells you what he's likely to do, and how you should act in your turn. That knowledge serves as a bulwark against the force of ever-changing circumstances. Feeling hurried or stressed makes people less likely to help another person, but a reminder of their duties as members of a human kind can make them turn back. A military uniform, a Hippocratic oath, a bracelet that asks Christians "what would Jesus do?" - such tokens of membership make our actions more consistent than they would otherwise be. They remind us to look beyond the emotions of right here, right now, and act as members should. The navy is supposed to defend the nation, doctors to heal the sick, Christians to be Christlike, no matter what.

So these human kinds offer the joy of belonging to something larger than the little self; they let us thrill to a feeling of existence across centuries and continents, of being alive so long as "we," our kind, endure. The first type of human kind is a category based on traits ("white hair equals old person," for example). The second type is based on obligations ("Soldiers must serve the nation"). An institution of this second sort, we sense, must act consistently, even if individual members fail it. That's what defines human kinds of this second type: the things people do to belong.

That consistency makes it easy to think of this sort of human kind as if it were a person itself - a being with thoughts, plans, and feelings of its own. Nations have moods, schools have spirits, and a congregation can repent. You can say the navy has decided to seek more recruits next year. It's harder to come up with a sentence about how the world's mothers have decided to act.

Nonetheless, these two viewpoints - human kinds as categories and human kinds as entities that happen to be made of people - are looking at one phenomenon. All human kinds have aspects of both, though the proportions can change over time. Half a century ago in North America, "homosexual" was mostly a category for people. Today in many Western nations, gays and lesbians are seen as an entity that wants, hopes, decides, and votes. On the other hand, the Norwegian community of New York City used to be an entity, with neighborhoods, clubs, and churches that helped organize people's lives. "Norwegians" made up a thing made of people. Today New York's Norwegians, despite annual parades, are mostly members of a category for people.

Underlying our myriad human kinds, then, is a fundamental unity. It is reflected in the way people blur distinctions. Most people don't blink at the much-used phrase "moderate Hutus," for example, even though "moderate" and "militant" describe political convictions and the Hutu are an ethnic group. Yes, it's birth that makes you a Brahmin, but it takes training to live as one; yes, you must sign up for army service, but many a son and grandson of military officers has enlisted because he felt "born to it." You become an employee of a corporation to make a living, but you can come to feel a familylike love for the place - like those Apple Computer employees who were said to bleed in the six colors of the company logo.

In fact, people speak about all human kinds with one language; something said about one can be said about any other. For example, when the American political commentator Paul Begala interviewed a prominent congressman, J. C. Watts, for a television program in 2002, he began: "Let me say, I'm a liberal. You're a conservative. That's not our biggest difference. I'm white, you're black, that's not our biggest difference. I'm a Texas Longhorn and you're an Oklahoma Sooner, and . . ."

"That's our biggest difference," Watts said.

"That's the biggest," Begala replied. "That's bigger than anything else."

It wasn't, of course. Banter about college football was, in fact, a demonstration that there was a way in which they were not different. They were getting in sync, establishing that there is a human kind to which they both belong: powerful Washington guy. (For men of this tribe, as the journalist Nicholas Lemann noted, sports joshing is a way to signal that "membership in a community of important people trumps the enmity the system forces them to act out.") Notice, though, what made the conversation possible: the way politics, race, and sports fandom can be talked about as if they were the same. Why should these different human kinds, with their different purposes and histories, feel equivalent? One reason is that they share mental processes. Your ability to think of people as "German" partly depends on your general ability to categorize anything- to divide a flood of perceptions into birds and trees, gears and Gummi bears, hip-hop on the radio and grapes in a bowl on the table. Pigeonholes for people get some of their qualities from the mental equipment that makes pigeonholes for everything.

Categories of all sorts help explain what's happened and predict what will come next. Human kinds help predict what people will do, and there too they draw from a general capacity to find causes and patterns. "Today is cloudy and humid" is information that licenses you to predict that it might rain. Similarly, "He is a graduate of the University of Oklahoma" is a piece of information that lets you predict a stranger likely will follow the Sooners through football season.

You also use human kinds to understand yourself. That means they must link to the brain's systems for monitoring the body, both inside and outside of your conscious awareness. "I feel tired and achy because I have been working hard" is a statement that combines your mind's reports on your mood and bodily state with memories and thoughts about cause and effect. "I get my self-reliance from my pioneer ancestors" is the same kind of multiprocess report, which relates your sense of yourself to your knowledge of cause and effect.

There are other ways in which thoughts and feelings about human kinds must involve a general-purpose mental machine, applied to the particular problem of understanding others. For example, people tend to treat nonhuman things as if they were human. We say cancer is a cruel disease, as if cancer had a personality; we yell at the crashed computer, as if it decided to ruin our file. Whether or not it can be true, we assume that things happen as the result of thoughts and moods in the minds of other beings. When people do the same thing to a tribe, as when they say, "America is arrogant," or "Buddhists are gentle," they're applying this general-purpose habit to human kinds.

Copyright © 2005 by David Berreb

About the Author

David Berreby was born in France, raised in the United States, and educated at Yale. He has written on scientific and cultural issues for the New York Times, The New Republic, Slate, Lingua Franca, The Sciences, and Discover, among other publications. He lives in Brooklyn, New York.