Disagreeing with Hillary Clinton on human genetic differences

It's not really a politician's job to explain human biology to high school students. Still, with the number of politicians in New Hampshire this year, they seem to have been impressed into service. So Hillary Clinton was talking about biology to a graduating class in Manchester:

When offering serious advice to the graduates, Clinton told them that their strengths lie in their differences -- those tiny differences that aren't at all significant.
Clinton cited genetic research that shows humans are 99.9 percent the same and the graduates should embrace what they share, not the material they don't.
"That the differences in how we look -- in our skin color, our eye color, our height -- stem from just one-tenth of 1 percent of our genes. And the differences among us -- our cultures, our religious beliefs, the music we like -- it is all so small a distinction in our sea of common humanity," she said.

Now, pointing out that humans are very similar to each other is a worthwhile message. It emphasizes that we should work together to solve global problems, and that we shouldn't be distracted by minor differences. That is the bottom line in Clinton's speech, according to the AP story:

"I know it seems daunting. We tend to focus a lot on the things that divide us -- the things we disagree about -- don't we?" she said. "But in doing so, we fail to take into account a basic scientific truth about who we are."

I'm uncomfortable with this formulation, though.

It's not just the "one-tenth of 1 percent of our genes" thing (although we differ by one-tenth of 1 percent of nucleotides, this is enough to make coding differences in a large fraction of our genes). Nor is it the new observations on copy number variation, which makes humans quite a bit more different from each other than the older figure.

I disagree with Clinton: the average amount of genetic similarity between people is irrelevant to how we should act toward other people.

Why irrelevant? Well, take the copy number variation as an example. It shows that humans are substantially more genetically different, in terms of nucleotides, than 0.1 percent. Does that mean it's OK to be a racist now? Does copy number variation provide another reason to diverge on global warming strategies?

No, of course not. It's just irrelevant to these questions. Genetic similarities, whatever they may amount to, are not a reason for moral action.

Am I just splitting hairs? Isn't it ultimately benign to point out how similar people are to each other? I mean, their usual reaction is "Gee whiz, 99.9 percent seems pretty alike to me!"

But I actually think that moral arguments based on genetic "realities" are ultimately dangerous.

For one thing, one-tenth of 1 percent of 3 billion is a heck of a large number -- 3 million nucleotide differences between two random genomes. Most of those genetic differences don't make a significant phenotypic difference. But a few do. There is no argument from the overall level of similarity (99.9 percent similar, or whatever) that cannot apply equally to some specific similarity or difference. Maybe some scientist says the average level of similarity is important. But some racist can just as easily say that the specific genes related to skin color are the important ones. The question of what is important is simply not a scientific one. The more we make these statistics out to be reasons for moral equality, the more we legitimize people who want to use genetics to prove moral inequality.

For another thing, if we condition people to believe that we should treat people according to their genotype (which is, after all, mostly identical), then what happens tomorrow when scientists find some really important genetic difference? When it suddenly matters what allele you have?

For instance, if a new disease emerged to which all people with type A blood happened to be immune?

Clearly, the moral outcome is not to shrug and say the difference can't possibly exist because we are all 99.9 percent the same. Nor is the moral outcome for people with type-A blood to withhold tax money spent on research. The proper moral response is to find a cure for the disease, regardless of who it afflicts. Genetic information may be important toward finding that cure, but it cannot tell us whether we should find a cure, or how much effort we should spend on it.

My bottom line: no matter how genetically similar or different people are, genetics cannot justify moral action. Although we are now in a time when it is fashionable to use genetics as a kind of self-evident argument for human equality, not very many years ago fashionable opinion found self-evident racial superiority. And given the increasing prevalence of genetic testing of all kinds, the pendulum may well swing back the other way, giving rise to various flavors of "allelism". I think it is better to recognize that moral action doesn't derive from scientific observations.

(via Eye on DNA -- which also points out the problem of more extensive copy number variation)

UPDATE (6/15/2007): A reader writes:

To the extent you're just saying "is" doesn't make "ought", I find nothing to disagree with in your post. Unfortunately, though, your moral reasoning, while a step above Hillary's, still leaves something to be desired.
"Nor is the moral outcome for people with type-A blood to withhold tax money spent on research. The proper moral response is to find a cure for the disease, regardless of who it afflicts."
I'd like to see you justify this claim. What if the disease afflicts a tiny minority, and type-A people have their own diseases to worry about? You'll still stand up, courageously, and declare how other people's money should be spent?

Simple answer: I have blood type O. You're damned right I'm going to tell them how to spend their money!

(Less) simple answer: If we are going to give up the idea that moral reasoning is not identical to scientific reasoning, then we probably will observe (and accept) that different people have different beliefs about moral propriety. I don't know if this reader holds a belief inconsistent with mine, but someone very well might. Maybe they think that no government should be able to compel taxes, for example. Nothing wrong with that.

But there are any number of genetic disorders that (a) are completely determined by genotype, and (b) affect a small minority of people. Our normal approach to these has not been to say, "Sorry, guess you're out of luck." My example of a novel disease afflicting non-type-A people has a dire appearance, because it seems so random. But of course it's no more random than cystic fibrosis.

Do we have a moral obligation to conduct, pay for, and assist in finding a cure for CF? Probably not. We certainly don't have a moral obligation to exhaust the treasury, impress labor, or abandon all other research to find such a cure. No one can be expected to do the impossible. But I argue that it is morally desirable to conduct such research as is practical. And people who conduct such research do so not only for pecuniary reasons but also for moral ones.