Is racism something that's learned, or is it innately endowed?

I don't think either of those is the right answer. There's no doubt that there's a rich, complex human nature. We're not rocks. Anybody sane knows that an awful lot about us is genetically determined, including aspects of our behavior, our attitudes. That's not even a question among sane people.

When you go beyond that and ask what it is, you're entering into general ignorance. We know there's something about human nature that forces us to grow arms, not wings, and undergo puberty at roughly a certain age. And by now we know that acquisition of language, growth of the visual system and so on, are part of human nature in fundamental respects.

When you get to cultural patterns, belief systems and the like, the guess of the next guy you meet at the bus stop is about as good as that of the best scientist. Nobody knows anything. People can rant about it if they like, but they basically know almost nothing.

In this particular area we can at best make some reasonable speculations. I think the one I've outlined may be a reasonable guess. It's not so much that racism is in our genes. What is in our genes is the need for protecting our self-image. It's probably in our nature to find a way to recast anything that we do in some way that makes it possible for us to live with it.

It's the same in the broader social sphere, where there are institutions functioning, and systems of oppression and domination. The people who are in control, who are harming others -- those people will construct justifications for themselves. They may do it in sophisticated ways or nonsophisticated ways, but they're going to do it. That much is in human nature. One of the consequences of that can turn out to be racism. It can turn out to be other things too.

Take the sophisticated ones. One of the intellectual gurus of the modern period in the United States was Reinhold Niebuhr. He was called the "theologian of the establishment." He was revered by the Kennedy liberal types, by people like George Kennan. He was considered a moral teacher of the contemporary generation.

It's interesting to look at why he was so revered. I went through his stuff once. (There was supposed to be a chapter about him in one of my books -- but the publisher thought it would be too arcane for the audience, so I didn't include it.) The intellectual level is depressingly low -- you can hardly keep a straight face.

But something made him appealing -- his concept of the "paradox of grace." What it comes down to is this: No matter how much you try to do good, you're always going to do harm. Of course, he's an intellectual, so he had to dress it up with big words, but that's what it comes down to.

That's very appealing advice for people who are planning to enter a life of crime -- to say, "No matter how much I try to do good, I'm always going to harm people. I can't get out of it." It's a wonderful idea for a Mafia don. He can go ahead and do whatever he feels like. If he harms people, "Oh my God, the paradox of grace."

That may well explain why Niebuhr was so appealing to American intellectuals in the post-World War II period. They were preparing to enter a life of major crime. They were going to be either the managers or the apologists for a period of global conquest.

Running the world is obviously going to entail enormous crimes. So they think, "Isn't it nice to have this doctrine behind us? Of course we're superbenevolent and humane, but the paradox of grace...."

Again, if you're an intellectual, you dress it up and write articles about it. The mechanisms, however, are quite simple.

I suppose all of that is, if you like, part of our nature, but in such a transparent way that we can't seriously call this a theory. Everybody knows from their own experience just about everything that's understood about human beings -- how they act and why -- if they stop to think about it. It's not quantum physics.

What about the so-called "competitive ethic?" Is there any evidence that we are naturally competitive? Many proponents of free market theory and market capitalism say you've got to give people the ability to compete -- it's a natural thing.

There are certainly conditions under which people will compete, and there are also conditions under which people will cooperate. For example, take a family. Suppose that whoever is providing the money for the family loses his or her job, so they don't have enough food to eat.

The father is probably the strongest one in the family. Does he steal all the food and eat it, so all the kids starve? (I guess there are people who do that, but then you lock them up. There's a pathological defect there somewhere.) No, what you do is share.

Does that mean they're not competitive? No. It means that in that circumstance, they share. Those circumstances can extend quite broadly -- for example, they can extend to the whole working class. That's what happens in periods of working class solidarity, when people struggle together to create unions and decent working conditions.

That's true of the United States, after all. Take a look at the Homestead strike a century ago [when Andrew Carnegie locked striking workers out of a steel mill in Pennsylvania]. That was a period of enormous ethnic rivalry and racism, directed mostly against Eastern European immigrants. But during that conflict they worked together. It's one of the few periods of real ethnic harmony. They worked together with Anglo-Saxon Americans and the Germans and the rest of them.

Let me tell you a personal story. I'm not particularly violent, but when I was in college, we had to take boxing. So the way we did it was to spar with a friend, wait until the thing was over and go home. But we were all amazed to find that after doing this pushing around for a while, we really wanted to hurt that other guy, our best friend. We could feel it coming out -- we wanted to kill each other.

Does that mean that the desire to kill people is innate? In certain circumstances that desire is going to come out, even if it's your best friend. There are circumstances under which this aspect of our personality will dominate. But there are other circumstances in which other aspects will dominate. If you want to create a humane world, you change the circumstances.

How crucial is social conditioning in all of this? Let's say you're a child growing up in Somalia today.

How about a child growing up two blocks from here in Cambridge? Just last summer a student at MIT was killed -- knifed -- by a couple of teenagers from the local high school. They were engaged in a sport that works like this: They walk around and find somebody walking the street. Then one of the teenagers is picked to knock the person down with a single blow. If he fails to do it, the other kids beat the kid who failed.

So they were walking along and saw this MIT student. The chosen kid knocked the student down with one blow. For unexplained reasons, they also knifed and killed him. The teenagers didn't see anything especially wrong with it. They walked off and went to a bar somewhere. They were later picked up by the police because somebody had seen them. They hadn't even tried to get away.

These kids are growing up in Cambridge -- not in the wealthy sections, but probably in the slums. Those aren't Somali slums by any means, or even Dorchester slums, but surely kids in the more affluent suburbs wouldn't act like that.

Does that mean they're different genetically? No. There's something about the social conditions in which they're growing up that makes this acceptable behavior, even natural behavior. Anyone who has grown up in an urban area must be aware of this.

I can remember from childhood, that there were neighborhoods where if you went, you'd be beaten up. You weren't supposed to be there. The people who were doing it -- kids -- felt justified and righteous about it. They were defending their turf. What else do they have to defend?