How many different races are there? Pick a number, any number, says philosophy professor Philip Kitcher. Wherever there is an agenda there is a division to be made; race is a social construct with scientific levers. “If there’s one thing that we’ve learned from biological science and psychological science over the last century, it’s that there’s an enormous amount of variation within the groups that we’ve traditionally thought of as races, far more than there is between the groups we’ve traditionally thought of as races.” This makes sense; historically, we’ve drawn the line wherever it has suited the mainstream agenda. Humanity can be divided into two races, which would see Africans, Europeans and most Asians as one unified race. Or it could be divided into three races, which would separate Africans into their own group. You can keep dividing humanity down into more and more refined biological groups until you have 10 or 20 or 30 different races. But what would be the purpose? Our mistake has always been confusing groups for classes anyhow. Philip Kitcher is the co-author of The Seasons Alter:How to Save Our Planet in Six Acts.

Philip Kitcher: So what should we make of the concept of race? There are a lot of anthropologists who would say we should just throw this concept away completely. There’s no basis for it. And those people are responding to what many scholars call essentialist notions of race. There’s something about this particular group of people, perhaps about their anatomy or their physiology or their brains or their genes or something like this, that differentiates them from various other groups of people. If there’s one thing that we’ve learned from biological science and psychological science over the last century it’s that there’s an enormous amount of variation within the groups that we’ve traditionally thought of as races, far more than there is between the groups we’ve traditionally thought of as races.

It turns out that if you look at things from a genetic point of view the certain kinds of molecular sequences are more common in some groups than in other groups. That’s because during the course of human history these groups have been separated from one another. They haven’t intermarried and that’s given various chances for various kinds of genetic material to become prevalent in some groups but not in others. But the first thing to say about that is that these differences are trivial! Largely trivial; there are some cases, such as well known diseases that tend to affect some groups more than others, that is not trivial for the sufferers. But by and large these differences are perfectly trivial.

Now about 15 years ago a tremendously brilliant study was done by researchers at Stanford that actually divided the human population into groups that the researchers themselves called interbreeding populations. They didn’t want to call them races but very quickly the popular press picked this up and started referring to them as races.

So you might start out with the human population and ask the following question: on the basis of biological evidence, gene frequencies, molecular frequencies of DNA sequences in different populations, what would you get if you wanted to divide the population into two? Well you’d get actually Africans and most Asians, central and western Asia, and Europeans as forming one group, and the rest of the human populations forming another group. Now what would happen if you did it into three groups? Well then you’d get the Africans separated out from the Eurasian population. What would happen if you did it for four groups? Five groups? Six groups? Seven groups? Eight groups? Nine groups? The first five or so of these give you something like sort of standard racial groups with a few odd little twists. The sixth gives you—as there’s sixth of these groups—gives you a tiny little population that has been isolated because of mountain barriers in Asia.

Now those are genuine divisions that have come out of our human history and that are still present in the DNA sequences of the genomes of various people. But whether we want to draw any distinctions at all within the human population is completely up to us. Remember how I did this: I said 'If you want to divide the human population into two, to three, to four, to five, to six, to seven, this biology will tell you how to make the biologically significant decisions.' But why should we want to do that? Is there a point in doing that?

Well sometimes there is a point. Sometimes there’s a point in recognizing that certain people are more closely related to other people, if you want to do medical transplantation, for example. There is a point in saying, well what you need is somebody to give you a kidney who comes from this particular group. But there are other people who say this is just the sort of stuff that breeds discrimination and prejudice as it has in the past, and there are yet other people who say precisely because of that discrimination that we’ve had in the past it’s important to acknowledge these groups.

So I want to say there’s a certain kind of biological phenomenon that stands behind the historic process of dividing people into racial groups. But actually these racial groups are constructed by us. It’s we who decide that we want to draw the lines and the basis on which we should decide that is an ethical basis. We should decide how we actually treat people most fairly. So the issue is really not whether there are racial groups. I mean we could think about racial groups as one, two, three, four, five, six, seven and so on, in divisions in this initial human population. But it’s a question of what divisions, if any, are useful from the point of view of justice and fairness. And that I think is the right way to think about race. So is it scientific? Well there’s sort of something scientific lurking in the background. Is it socially constructed? Yes, it’s socially constructed. And the social construction ought to proceed on the best ethical basis we can find.