davidberreby.com

Q. What's your book about?

A. It's about something everybody does and no one talks about, every single day: Dividing the world into ``Us'' -- the people who matter, the people we care about -- and Them. It's about that first day in a new school when you felt ``left out.'' It's about a woman in Sri Lanka smugly saying that her neighbors lost their kids in the tsunami because they didn't believe in the right religion. It's about that aspect of the human mind that let politicians in Rwanda persuade thousands of sensible people that it was right to kill their neighbors. It's about how ``red state'' and ``blue state'' went from being election-night jargon to a way of describing religion, lifestyle, culture and politics.

What makes all that possible is the brain's built-in, automatic ``Us-Them meter.'' This part of the mind is a lot like the part that lets everyone learn a language; it's shared by all people. Of course, we don't all speak the same language. People learn Chinese in Beijing and English in Boston and Hindi in New Delhi. In the same way, some children grow up learning that race is the most important division in life, while others are taught that it's religion, and others might learn that it's being a Southerner.

Underneath the different forms of division, though, is that one, shared mechanism in the human mind. Us and Them describes this, in the course of explaining what research supports the idea in various fields, ranging from neuroscience to anthropology to psychology and history. As I make this argument, I also touch on what I think we should not believe about this part of human nature. (In other words, the book is also a look at theories that I don’t agree with.) And I try to sketch how a new view of this old mystery will overturn a lot of the assumptions we bring to political and economic problems, like terrorism, immigration policy and law enforcement, to name a few.

Q. This sounds like kind of a downer.

A. Only if you look at the dark side. But the Us-Them meter has a bright side, too. Devotion to ``our people'' has made ordinary human beings into heroes; it can make a lost soul change her life. It can make someone fight injustice, even when the official line is that injustice is no problem. Devotion to Us -- our religion, our country, our culture -- is the way we find something to live for, bigger than our little selves. Anyway, love it or hate it, a sense of Us and Them is part of being a person. Many other animals would die defending a mate or a child. But only a human being will die for a complete stranger, if that stranger is ``one of us.''

Look at it this way: On Sept. 11, 2001, 19 young men decided they could kill thousands of people they had never met, because those victims didn't count -- they weren't part of ``Us.'' On the other hand, hundreds of people gave their lives that day to save strangers. Because, they felt, ``we're all in this together.'' The Us-Them aspect of the human mind made possible both the crime and the nobility of the response to it. This part our nature isn't good, and it isn't bad. It's just there, a part of being human, and we need to understand it.

Q. So, is Us and Them a science book, or current events, or psychology?

A. It's all of the above.

Q. Hasn't all this stuff been figured out already? I seem to remember learning about stereotypes in college . . .

A. Yes, some people remember reading Freud on the subject, or Gustave Le Bon, the author of The Crowd, or learning about stereotypes, which is a term coined by the American columnist Walter Lippmann. But a lot of what people believe because they read it in college is regarded, by today’s researchers, as dead wrong. I tracked where all of today's clichés and jargon come from: Terms like ``stereotype,'' ``prejudice,'' ``ethnocentrism'' are given their due in Chapter 10; the ``selfish gene,'' ``kin selection'' and ``reciprocal altruism'' are in Chapter 15. The book describes why Freud’s ideas on this subject are best forgotten, and why Darwin’s original writings may be better than the theories of later Darwinists.

Q. So there are surprises in here for people who think they know the subject?

A. Sure are. The book addresses widespread myths.

Q. Such as?

A. Ahem. Here's a list.

Myth 1: We can measure differences among races, ethnic groups, religious communities, nations, etc. So the categories we use for people are objective, true facts.

False. As Chapter 3 explains, you can measure real, objective differences between any two people, or any two groups of people. And we ignore all kinds of real distinctions when we lump people together. For example, left-handed people are biologically different from righties, but southpaws don't get their own flag. We think we measure, then make categories. In fact, we start with categories, and then take measurements to suit. In Chapter 4 the author tastes a ghastly chemical called PROP, and learns that other people don't sense it as much, while a few others in the room can't taste it at all. That's a real genetic difference -- but it cuts across racial, cultural and national lines. The room's ``super-tasters'' were white and Asian, American and European. So were the non-tasters.


Myth 2: People have always recognized that race and ethnic origin are what matters most in life.

False. Chapter 4 also notes just how recent these modern ideas are. The coinage ``ethnic group,'' for instance, is only 50 years old. Census data about race around the world cannot be combined -- because definitions of race vary from nation to nation. (And from decade to decade: when the United States changed the classification of Hindus from ``white'' to nonwhite in 1920, 65 naturalized Hindus lost their citizenship.) Chapter 2 describes ethnic groups that have vanished from history, in Europe and Asia, simply because circumstances changed. And Chapter 11 recounts fascinating research that showed how a new ethnic group was created in 20th century Shanghai.

Myth 3: Blood is thicker than water, and that explains racial and ethnic strife.

False. Chapter 5 explains how a recent genetic study of ethnic groups in Central Asia showed that members of each tribe were no more closely related to fellow-tribespeople than they were to neighboring tribes. Chapter 5 also reminds you that we're all related to everyone who lived long ago -- thousands of years ago, your ancestors were living on the banks of the Yangtze and the Amazon, no matter what your skin color or language. Whenever we celebrate our link to long-dead forebears, we're choosing some ancestors and ignoring others. (Today's fad among African-Americans for seeking genetic ties to Africa, for example, ignores the 30 percent of their DNA that comes from Europe.) Chapter 4 explains why we all love to do this. Chapter 14 explains how genetics is one kind of knowledge, and race is another, and why the twain will never meet.

Myth 4: Since race and ethnicity are not biologically real, we can forget about them and live happily ever after.


False. Chapter 5 shows how, once people are persuaded about a category, they will act as if it is real, and that gives it teeth. It's called ``the looping effect of human kinds,'' and it means that race is a part of life wherever people believe it is. When it comes to Us and Them feeling, biology doesn't matter. What counts is how the mind is persuaded to believe in categories like ``normal people'' and ``gay people'' (both discussed in Chapter 3). Americans spend a lot of time arguing about which categories are ``real.'' US AND THEM explains why those arguments are, for both sides, a waste of time.

Myth 5: The world is enduring a ``clash of civilizations.''


False. This popular idea of Samuel P. Huntington's assumes that people live and act as members of only one ``tribe'' at a time -- the only way civilizations can clash over centuries is for everyone to stay on his side of the line. Chapter 4 explains why this does not happen, and never has happened in human history. The natural state of the mind is shiftier than that. We see ourselves as members of many different tribes, all at once. Which one counts right here and right now? It depends on what is happening around us. For example, Chapter 10 tells how two soldiers on opposite sides of a great war came to bond over their love of the same poem. Chapter 4 tells the story of Charles Johnston, an 18th century white American who was kidnapped by the Shawnee Indians in 1790. Johnston found that the only other person who spoke English in camp was a black slave. And suddenly, language, to him, counted for a lot more than skin color. In fact, the book features many true stories of real-life people switching from one map of humanity to another.

Myth 5: The kind of person you are determines how you'll act.


False. What counts isn't what you are; it's where you are -- what's going on around you. Chapter 1 describes how even future ministers in a divinity school will rush by a person in trouble, if they're in a hurry. In contrast, the students with plenty of time were more likely to stop. One reason we care about categories like race and nation is that we think they will tell us what people will do. That’s not a good bet.

Myth 6: Prejudice and violence are part of human nature. We can't control it.


False. Chapter 10 points out that even the violent 20th century was far from being the worst in history, and that most places known for religious or ethnic strife have known long periods of peace. There's nothing inevitable about ``Us versus Them'' violence -- it's the product of skilled manipulation, working its wiles on our built-in brain mechanisms.

Chapter 11 explains those techniques -- the many ways that people are made to look and feel like ``Them,'' and never like us. For example, if you want me to hate Group X, tell me they're diseased. It's rhetoric as old as the Roman Empire and as modern as today's claims that gay men die young because of their ``unhealthy'' lifestyle.

Chapter 12 compares these techniques to an addictive drug. They're bad for each of us, and bad for society, and scientists are coming to understand how they work on the brain.

Myth 7: Arguing about labels and pigeonholes is ``just semantics.'' We don't need to worry about it.


Tell that to Daryl Atkins. He was supposed to be executed in Virginia, but the state held off, because his IQ score showed him to be officially classed as retarded. Unfortunately for Mr. Atkins, work on his appeals apparently sharpened up his mind. He now scores above the cut-off for retardation, which means he is now in a different category of human being. He is now in the category of people intelligent enough to be given the death penalty. Perhaps the academics who dreamed up IQ tests never imagined a score could be a matter of life and death, but so it is, now. (This is news from last month -- not in the book but an example of how the book relates to news stories, every day.)

Chapter 1 describes how an academic term was turned, thanks to the Us-Them mechanism, into a fatal, tribal belief. ``Aryan'' began its life as a category for dead languages. A few decades later, it was the basis for genocide. The categories that we use for people always matter.

Q. Hmmm. Well, I don’t know. This doesn’t sound like what I learned in school.

A. It’s not. In order to avoid repeating what’s been said already for centuries, I’ve tried to define the problem in an unfamiliar way. The book isn’t about race, or caste, or religion, or nationalism; it’s not about unions or political parties or gangs of sports fans, either. It’s about all those phenomena. They all stem from the mind’s knack for thinking in categories that cover more than one person and fewer than all people -- what some thinkers have called ``human kinds.’’ I’ve adopted that term.

Q. If these ``human kinds’’ are just products of human minds, then how come there are real, physical differences between populations? Look at, say, African-Americans and Jewish Americans. People whose ancestors were Ashkenazic Jews can be carriers of Tay-Sachs disease; people of African ancestry might carry the gene for sickle-cell anemia. That's a real difference!

A. Sure it is. Our beliefs about human kinds are not fantastical. If we didn't see real, apparent, measurable differences among the categories, they would not convince us.

But you don't believe in the categories ``Hindu'' and ``African-American'' and ``Italian'' because you've pored through hundreds of thousands of hospital files. You believe in them because you learned them as a child. Because you were told they existed, you're primed for evidence that they are real. Keep that sequence in mind: First, the category, second, the evidence.

Q. And that evidence exists!

A. Yes, but so does evidence for thousands of other human kinds in which you do not believe. If you want to find a biologically real, oppressed minority in any country, for example, look for all the left-handed people. They're disparaged in proverbial phrases like the left-handed compliment and the sinister atmosphere (``sinister'' derives from the Latin for ``left''); thousands die every year from the use of products made for righties. Yet there are no social movements or political parties or literature courses devoted to them.

Left-handers aren't asking for Lefty-Only dorms on college campuses because no one believes in that category as a meaningful human kind. Just as no one believes in human kinds like ``people who live at odd-numbered addresses'' or ``people who can't carry a tune.'' Give me any hundred people selected at random, and I can divide them every which way, into groupings that will fit some real measurement system.

Human kinds like race, ethnic group, nationality, and sexual orientation are not baseless. But they make no more sense than alternative categories, which we do not use. That's how we know that the source of our beliefs is not the physical evidence.

Q. If human kinds are so flexible, how come population biologists can trace different migrations from thousands of years ago? They can tell that the Basques are distinct from other Europeans, for example. Doesn't that mean Basque differences from other people are ``in the genes''?

A. No. You're mixing up two kinds of genetic research. The first kind traces the ancestry of today's populations. The second kind looks at how genes influence behavior.

Population genetics works by identifying markers that are common in a particular group, and rare in others. Many genes come in several versions, called alleles. Each allele may be common, but it can be quite rare to have it occur in combination with other particular alleles (in the way that cards dealt from a deck seldom combine into a Royal Flush). If a bunch of alleles keep turning up as a set, it suggests a single ancestor for all the people who have them. With such a marker, you can distinguish Basques from other Europeans. But the markers used by population geneticists are not the genes studied by behavioral geneticists.

Behavioral geneticists try to work out the correlation between particular genes and behaviors or tendencies, like intelligence or shyness. No mainstream researcher has found that such genes occur more often in one human population than they do in another. Again, the genes used to track populations are different from the ones used to research behavior-gene links.

Anyway, population genetics is a comparative field. Finding a marker for one population means it is frequently found there and rarely found elsewhere, but it does not mean everyone in that group has the marker. For example, there is a genetic marker on the ``Y'' chromosome associated with the Kohanim -- a subset of Jewish men said to be descended from the priestly caste founded by Moses' brother, Aaron. A significant number of Jewish men have this marker. Many don't. Meanwhile, a significant number of Palestinians also have the same indicator in their DNA.

Unless you want to drive a lot of Jewish men out of Judaism, and invite a number of Arabs in, then, you'd be better off leaving the genes to the geneticists. Jews, Palestinians and the other human kinds are created at the level of psychology and society, not in the genes.

Q. Wait a second -- how can genes be a marker for a population, unless that population kept itself apart from everyone else? Populations don't breed with each other, which means they're keep the boundaries locked up tight. So people don't just change labels whenever they feel like it!

A. You've got me there. Except that I never said people changed at the drop of a hat. The extent to which genetic markers and cultures match is a matter of controversy. But let's just agree that, in many situations, people are encouraged to keep to themselves, and not to marry ``Them.''

That doesn't undermine my argument. In fact, it bolsters it: What's the point of a human kind that doesn't matter to anybody? My message is not ``la-di-da, anyone can be anything''; rather, it's that these limits we place on ourselves and our perceptions originate in the mind, not the world. Are the limits real? Yes. Until we decide that they aren't. We make them; we unmake them. We need to understand how.

Q. You spend a lot of time on stigma, arguing that it’s a way of manipulating the mind’s innate faculty for human kinds. It sounds like you're saying there's no real reason that some people do well in life, while others don't. But we all know some people are better at life than others. Why can't you face that?

A. Because I think it's a stupid assumption. It states something patently untrue: That conduct which succeeds in some situations must succeed in all.

Consider an extreme example of success, as measured by wealth, power and impact on history. Assume that a lot of what made Napoleon Bonaparte was in his genes. That's a big assumption, but, for the sake of argument, figure Napoleon would have been roughly the same man if he had been born 50 years earlier. Would he have become a world-historical figure? With no French Revolution for his impulses and instincts to play in; no way up, past the barriers of class in the France of Louis XIV? I don't think so. The traits that made Napoleon successful in a time of upheaval would have made him fail in different circumstances. He said so himself.

So, yes, of course, some people do better with their circumstances than others -- they score better on tests, they shine in job interviews, they can handle work and family life while other people struggle. But their success is a meeting of their characteristics with their circumstances. Change those circumstances, and someone else, with other characteristics, succeeds.

That's what's wrong with eugenics -- Francis Galton's idea that the human race would cultivate its ``best people'' and let them breed ever-better specimens of Homo sapiens, while ``inferior'' people would be kept from dragging us down. The theory only works if genes that make you a success in Galton's world would make you one in ours, and in the 22nd century. At the individual-person level of description, this means Napoleon thrives whether he is born a slave in ancient Rome, a peasant in medieval Africa, or a brazen risk-taker in Enlightenment Europe. I don't think that is true.

Q. But you could be wrong!

A. Yes. But it doesn't matter, because this claim has another flaw. This is a point made forcefully by Steve Hyman, the former chief of the U.S. National Institutes of Mental Health, who is now the provost of Harvard. The traits we would want to breed into a better race of humans -- intelligence, kindness, temperance, stamina, talent -- are not created by one gene each. Like most traits, these attributes are the product of many different genes, working in concert, in response to particular environments. That's also true of genes involved in birth defects, or in disorders like schizophrenia or depression.

So, as Hyman says, you can't say ``good'' versions of genes live in one person, while ``bad'' versions live in someone else. The relevant genes are in all of us. The same ``bad'' allele that marks a predisposition to schizophrenia in one person's genome may be harmless in another person's, because the second individual lacks triggers for the disease.

Say, then, that we could define the packet of genes responsible for making people conscientious. We would like to isolate those from the genes that make people suffer from obsessive-compulsive disorder. But we cannot -- because they're the same genes.

In other words, as Hyman so astutely says, there is no superior genetic code lodged in a few people, that we can find and promote. ``Good’’ genes -- and ``bad’’ genes -- are scattered in everyone.

Q. Aha! So you admit that there are good and bad genes!

A. Within a certain context, sure. But can we say gene X is always bad news? There is a gene that codes for a particular protein on the surface of human immune cells. One version of this gene is ``broken'' -- it fails to produce a proper protein. It would not be wrong to call it ``defective.''

However, in a world of widespread infection by the Human Immunodeficiency Virus, this ``defective’’ allele confers an advantage. The ``correct'' protein is used by the virus as a doorway to get into cells and propagate. People with the ``broken'' gene are highly resistant to AIDS.

Lynn H. Caporale, a consultant and writer in genomics, has rightly asked what might have happened to this allele if the human race had developed eugenic control over its DNA before AIDS struck. ``If we had `fixed' those doorways before HIV took hold,'' he writes, ``our genome would never have shown us the life-saving potential of drugs that could block the opening of this door.'' For genes, as for people, what is ``defective'' or ``deviant'' in one environment can become advantageous in another.

So there you have two reasons -- one, we can’t isolate genes for only desirable traits; two, the definition of ``desirable’’ is not fixed -- for refusing to sort people into superior, average and below-grade. At least, we can’t do that unless we answer a couple of other questions: Who is doing the sorting? And for what purpose?

Think of it this way: Suppose I told you that Mr. X was intelligent, conscientious, affable and disciplined, and so was a great success at his job. Would you want your child to be like Mr. X? What if I add that his job is Torturer in Chief in a vicious dictatorship? That puts a different value on his intelligence and discipline, doesn't it?

Q. What about all those surveys and studies showing that people befriend and marry and work with those who are similar to them?

A. There are lots of those. Their underlying assumption is that people begin by noticing similarity and then go out and find their friends, spouses, business partners and other companions in life.

But obviously the process works the other way, as well: If I spend 20 years married to you, I will probably end up feeling that we are similar. (In fact, studies have documented that people looking at pictures of strangers will find that the married ones look alike.) And if I want to get along, I will do well to decide that we are similar from the get-go.

Q. That's nice in theory, but can you come up with a real-world example?

A. Are you kidding? It's hard not to think of real-world examples. Life is full of situations that you begin in strangeness and end with you ``fitting in.’’ Military training; going to college; first months at a good job; political movements, teamwork in any voluntary organization. Human beings get in synch with those with whom they cooperate. That's the general rule. Part of getting in synch is deciding that everyone on the team is similar to everyone else.

Let me get specific. In the spring of 2004 a sad story emerged from the war in Iraq. One of three sisters, all serving in a National Guard unit there from the same family in Wisconsin, was killed in the line of duty. Her two sisters went home on leave, of course, but then they faced a difficult decision: Should they stay home, as is permitted to those who have lost a sibling? Or should they return to their units? It was a conflict between genetic kin -- the family -- and spiritual kin: their comrades in arms. 

And the important thing about their choice was not how it turned out but that it was difficult for them. If similarity were an objective, factual thing, the choice would have been clear. Their obvious similarities were to their family and neighbors in their home town. But similarity is something the mind creates: So they also felt that they were ``just like'' their fellow soldiers, from all over their state.

Finally, consider how easily people who think they are similar can change their minds. Every life has its quota of sadness about the people -- so like us! -- who turned into strangers. The rise of feminism around the world might be a good example: There are couples of similar ethnic, educational and class backgrounds, all over the world, in which women see things differently after they get a chance at education and income-earning. When life changes for them, thousands of women who were so similar to their husbands looked at themselves and decided they weren't really copies of their mates, after all.

Q. Jeez, why do I have to understand all this complicated stuff about how people come to believe things and act on those beliefs, when the big picture shows that people's beliefs don't matter?

A. In other words, you want to rely on theories like Marxism, which argues that people are shaped by the economic patterns of history; or hard-core sociobiology, which claims wars among nations aren't different from fights among chimpanzee troops? Or, one more example, Samuel P. Huntington's notion that ``civilizations'' must inevitably ``clash''? If you've got a big-scale theory that covers millions of people over centuries, then you don't need to know what's going on inside any one person's head, right?

Q. Exactly. Maybe all this thinking and feeling and perceiving doesn't matter in the big scheme of things; maybe the roots of behavior lie elsewhere.

A. Certainly, people do many things for reasons apart from their conscious thoughts or stated beliefs. The evidence for that is overwhelming. However, it does not follow that people's beliefs never matter.

When a father decides that his daughter should be subject to ``honor killing,’’ for example, he is deciding that the ties of morality that bind his people together are more important than the ties of family that bind him to his children. In that case, beliefs in his particular mind override the genetic drive to leave offspring in the world. A ``genes-only’’ thinker might say, well, honor killings are rare. They aren’t rare enough, unfortunately, but even if they were, that’s irrelevant. They happen often enough to show that the human mind is independent of simple genetic drives.

So, maybe human beings commit genocide for reasons that have something in common with the reasons chimpanzees kill members of a rival troop. Human beings do things that chimps don't. People have decided to stop genocides; and some resist going along with the killing; and others later change their minds about their conduct and express regret for things they once did with enthusiasm. If your explanation of genocide is all about what we share with chimps and ignores what makes us human, it won't include those facts.

Then, too, people change the categories they use for themselves, by thinking about them and persuading each other. So our definitions of what it means to be a Christian or a European or a socialist today are not those of 1905. That can only happen because people change their cultures; they don't just obey. So, again, it matters what people think.

Bottom line: No biologist would let a turtle expert claim he had figured out what makes ravens tick. So why should studies of bees or chimps be counted as complete explanations for people's actions? If your goal is to understand human behavior, you can't ignore the mental states that make us human. What's the use of a psychology that leaves out the psyche?

Q. Your book denounces easy debunking of the ``race isn’t real, it’s all social construction’’ school. But when you tell people their beliefs about their nations and cultures and religions are just make-believe, aren't you doing the same thing?

A. No. Cheap debunking is telling someone his beliefs are worthless. The debunker bases that claim on something he supposedly knows, which the poor fool doesn't -- deconstruction, post-colonial theory, sociobiology, you can take your pick.

I’m not doing that. I say your beliefs are not what you think they are. That doesn't make them dispensable or worthless.

And I'm not saying that what I know -- which I want you to know too -- gives me superior insight into you. Part of what I know is that people's beliefs about human kinds make sense of life, and make them improve themselves, and satisfy their wish to see above the smallness of this life, at this moment.

I'm just saying, think about how these beliefs come to you, and how you use them. Don't imagine you can live without them; don't spit on them. Just look at them!

Q. But anyone who reads your book is going to be more skeptical about his ties to human kinds -- his culture, his religion, his nation, to name three. I think that's terrible! Parents all over the world are struggling to preserve their cultures for their kids. What you say will make it easier for those kids to say ``I don't care about my heritage, I just want to go to McDonald's!''

A. The premise of that question is that traditional ways are under assault, and that this is bad for humanity. I will plead guilty to this much: I am not sure that is true. My hunch is that more people on the planet are made miserable by being told ``you must adhere to our traditions'' than are damaged by economic, cultural and political change.

And I don't think all these traditions are worth preserving. I do not think, for instance, that a culture in which women cannot be educated as men are, is worth preserving. In fact, I think the very fact there is an argument proves my point: If this culture is so terrific, why is there debate? Why would women try to get this education that is ``not our tradition,'' if they saw no benefit?

Q. But lot of traditions are helpful to people. A lot of them are good for our health, too. Obesity is rising around the world, in part because millions of people eat less like their ancestors and more like the kind of consumers that big corporations want -- fast-food fans, candy-bar snackers. You said yourself people need human-kind beliefs.

A. Right. That's true.

Q. But you'd leave them with nothing!

A. Actually, I agree that working to preserve a culture can be a good idea. But I think the idea poses a problem.

We all grow up being told what it means to be a part of ``our people'' -- however defined. We learn that we should adhere to the rules for our people because we have this mystical connection to each other, and to past members of our human kinds -- an invisible, immaterial essence that is shared by all of ``us.''

Now, for myths and stories and parables, that belief -- essentialism -- seems to be required by the mind. That's how we're convinced about the human kinds that we care about.

But a science of human kinds has to work according to science's rules, and that leaves no room for mystic essences. From a scientist's point of view, human beliefs stem from material causes. What makes millions of people think they're, say, Lutherans is activity now, in their heads. Part of that activity represents ideas about the past -- you can't be a Lutheran with no knowledge of Luther. But today's people move because of today's thoughts, not those of the dead.

So it's a contradiction to say, on the one hand, I believe in a scientific understanding of human problems and capabilities, but, on the other hand, I know a mystic American essence ties me to George Washington, Cole Porter and the people across the street. In turn, then, I can't say there is a mystic essence of a Siberian culture, which must not die, and therefore these children must learn their grandfather's language. That's just hopelessly soft-headed, to look hard at my own beliefs but give someone else's a pass.

It's also a form of meddling that I can't justify -- who am I to say that grandpa has more cultural essence in him than the kids?

So that's the problem: How can you stand for preserving cultural traditions without accepting essentialism?

One solution might be to reframe the question in terms of human rights. And this is what some activists are doing. They don't claim to know the essence of a culture, they don't claim this mystical entity needs help. Instead, they focus on today's people, today. And what they argue is that, for instance, the kids in my example have a right to know what their grandfather wants to teach them. Not because it's mystically true but because it's part of being human.

All of us are raised to be members of human kinds, by adults who got here before us. The human-kind faculty needs that experience, as the language faculty needs to hear a language. So we can define that experience as one to which we all have a right.

Q. So the kids in your example have a right to learn their culture, even if they don't want to?

A. Sure. Kids don't always want to go to school or learn to read or eat right, but they have, I think, the right to be reared. Maybe they'll reject their grandfather's version of their culture later in life, but they'll have it to wrestle with. I think this argument is worth thinking about. You can read more here.

Q. Your emphasis on how the mind makes up human kinds seems so disrespectful -- how can you be so cavalier about the bonds that tie you to your people, and your ancestors?

A. Well, take my word for it, I don't wear human kinds lightly. I'm proud to be an American, a New Yorker, and a secular humanist, too. I figure I can't ditch our human-kind faculty, so I might as well enjoy it, and make use of it. Those standards that tell me I'm not being as good a neighbor, or citizen, or brother as I could be -- they're a force for good.

But this fine guide for my behavior is not so good a guide to metaphysics. Human kinds become dangerous for everybody when people act as if these concepts are eternal, unchanging, unquestionable truths about the universe. Because, as Clifford Geertz once said, other people are just as real as you are. And they don't agree with you about which human kinds are best.

Now, do I get inspiration from stories about my Irish ancestors and their journey to the New World? Or from family lore about my Sephardic forebears? Sure. But ancestry is a mix of blood and myth; if a people has a distinctive ``ethnic'' feature, they usually share it with people who aren't members, but who happen to live nearby. The kohanim marker in Jewish men is also found, as I've mentioned, in the Palestinian population. Similarly, a study of Uzbek tribes found that members were no more likely to be related to each other genetically than they were to other people in the same country.

It's hard to say, then, what my tie to my ethnic ancestors amounts to. On the other hand, I can say this for certain: once we go back a few hundred years, I have ancestors all over the world. It's basic math: There are more than 6 billion people alive today, descended from only a few thousand people 150-200 centuries ago. Our ancestors are few, and we are many. So we have to share ancestors.

This is why a team of researchers led by Joseph T. Chang, who worked out a model of human ancestry, summed up their results this way: ''No matter the languages we speak or the color of our skin, we share ancestors who planted rice on the banks of the Yangtze, who first domesticated horses on the steppes of the Ukraine, who hunted giant sloths in the forests of North and South America, and who labored to build the Great Pyramid of Khufu.'' 

OK, so let's say I want to point proudly to the inheritance of my ancestors who built the Great Wall, or received the Ten Commandments, or devised the Magna Carta in 1215. When I do that, I'm choosing to prefer some of my ancestors over others. You call that respecting your forebears -- to sweep most of them under the rug?

Q. Still, it's exasperating that you talk about all human kinds as if they were the same thing. I mean, I feel bad when my favorite team loses, but that doesn't mean that being a sports fan is the same thing morally or intellectually as being a patriot, or a religious person, or a soldier. Differences matter!

A. I agree. One of the biggest obstacles to understanding human kinds is glib equivalence-mongering -- let's call everything a Holocaust, from the Irish potato famine to violence against women; let's say my Ukrainian grandparents' experiences as immigrants led me to understand the racism African-Americans have faced. That kind of talk is an invitation to stop thinking. You'll hear it most often from privileged people who want the victims of stigma to shut up. If I thought I had encouraged that kind of thing, I would be sad. But I don't think I have.

I've argued that human kinds emerge from a single mental faculty. That doesn't mean all human kinds are alike. Look at the best model we have for such a specialized faculty, which is human language. Chinese and Hindi and English are not the same. However, anyone can learn all three, because they all spring from a specialized ability of the mind to deal with parts of words, and whole words, and grammar, and meaning.

Now, if you met a linguist who was studying language in general, would you assume she thought Confucius was the same as Condorcet? Would you think she was denigrating the Chinese language by researching what it has in common with others?

Q. But what if everything we need to know about nationalism or fundamentalism or anti-Semitism is in the particulars? Maybe there's nothing to be learned from their common ground.

A. Maybe. That's an argument you can find, for example, in The Anatomy of Prejudices, by the psychoanalyst and author Elizabeth Young-Bruehl. She lays out the ways that anti-Semitism and racism and homophobia should not be understood in a single framework.

But she can't avoid some sort of generalization. No one can. If you want to distinguish racism from anti-Semitism, why stop there? Why not separate the anti-Semitism of 2005 from the anti-Semitism of 1905? Or that of Russia from that of Argentina? Then, too, Young-Bruehl discusses prejudice in a psychoanalytic framework, using concepts like ``id'' and ``superego'' and so on. (She treats thinkers who don't accept these theories as naive bumpkins. So even as she's distinguishing racism from ethnic prejudices, she's putting the entire human race into one general category: Beings who have ids and superegos.

If you want to explain the behavior of more than one human being, you have to generalize. So this isn't a fight between dumb generalizers and conscientious, smart people. It's a fight over which generalizations should be used.

The ones we glean from people around us as we grow up, like race and ethnic group and religious community, were created at the level of description that concerns itself with large populations of people. At the level of the individual mind, or the individual brain, these may not be the best generalizations to use for understanding what's going on. We won't know if we don't ask.

Jack Hexter, a medieval historian at Yale, once divided his profession into ``lumpers,’’ who like big generalizations, and ``splitters,'' who preferred to make distinctions. (Biologists took this to heart and now often talk of lumpers and splitters.) Hexter didn't say one temperament was better than the other. The world needs both.

Q. You've been emphasizing doubt, change, skepticism -- the science that's congenial to you! What about the other side?

A. Guilty as charged. But then, who doesn't do this? It's practically the definition of a writer: using words to make the world more to your liking. I’m sure an equal and opposite argument to mine could be written (though not by me). My book is one perspective on all this, contained within the news that human kinds are being studied by science in new ways. I like to think, though, that even readers who hate my ideas will appreciate that this question of human kinds is worth more attention than it has gotten.

REFERENCES

matter of controversy. .... Robert Sokal and his colleagues argue that shifts in the proportions of genetic markers from place to place in Europe line up with language boundaries. See Barbujani, G, and RR Sokal. "Zones of sharp genetic change in Europe are also linguistic boundaries.". Proc Natl Acad Sci U S A 87 (1990): 1816-1819.

For a counter-argument, see Rosser, ZH et al. "Y-chromosomal diversity in Europe is clinal and influenced primarily by geography, rather than by language." American Journal of Human Genetics 67 (2000): 1526-1543.


he writes Caporale, Lynn H. "Genomes Don't Play Dice". New Scientist March 6, 2004

Joseph T. Chang Rohde, Douglas L T et al. "Modelling the recent common ancestry of all living humans". Nature 431 (2004): 562-566

naive bumpkins. For example, in The Anatomy of Prejudice, Young-Bruehl places the 1960's-era work of Pierre L. van den Berghe, a sociologist at the University of Washington, on a list of ``Freudian (often without the name) investigations.'' These, she says, were the ``most important and suggestive of the period.'' (Page 99) Van den Berghe did not himself call himself a Freudian, but worse was to come. Later, Young-Bruehl writes, Van den Berghe ``converted to sociobiology in the 1970's, abandoning the important steps he had taken . . . '' (Page 112).

``lumpers,’’ Hexter's description is in Hexter, J. H. On Historians. Cambridge, Mass.: Harvard University Press, 1979. Page 241-242. He attributes the idea to his colleague Donald Kagan, a historian of the ancient world. Kagan, though, told me he picked it up from someone else, lost to memory. For an example of a biologist using the concept, see Diamond, Jared, "Race Without Color" Discover (1994): 83-89.