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| Modern genetics says there are no homogeneous, essential “races” |
tl;dr I used to think that “race” meant nothing, biologically speaking. Now I think it means not much.
In the 80s, I studied race as part of my BA in sociology, and I was proud to learn views that represented the best science. Experts such as Richard Lewontin and Stephen J Gould taught that what we think of as “race” does not correspond with human ancestry or meaningful biological differences among groups. Gould, perhaps the most storied popularizer of evolutionary thinking the 20th century, said, “There’s been no biological change in humans in 40,000 or 50,000 years”. Cultural change had taken over, the experts said, and biological change had ended. Based on that scientific understanding, it was impossible that people of different “races” could be biologically distinct in any way. Learning this view, I considered “race” to be as irrelevant to biology as astrological signs are. That was the 80s. Since then, two things have happened that led me to adjust my views, albeit not to reverse them. Personally, I married a black woman, and we raised a biracial daughter together. Scientifically, geneticists mapped the human genome. Based on new evidence, I now see differences in continental ancestry as biologically real but still mostly insignificant. That position contradicts today’s racists, who want us to believe that “racial” differences are telling and definitive. It also angers people who either still believe what Gould and Lewontin taught in the 80s or who think that we shouldn’t talk about the new evidence because it’s too problematic. A recent study suggests that teaching students the facts of human genetic variation leads to a significant reduction in prejudice, and that sounds great to me. The alternative—not talking about the new findings—means that racists can tell potential recruits that we egalitarians are hiding scientific information. If we act like we’re afraid of these findings, it helps racists spread the lie that the new findings are a threat to our egalitarian ideals. Our society has a problem with the return of racist pseudoscience. My view is that the best way to counter pseudoscience is to use good science.
Sometimes when people hear me talking about differences among “races”, they jump to the conclusion that I endorse all the claims people make about such differences, such as alleged innate differences in IQ. Let me clarify in advance that my point is just the opposite, that we should distinguish the claims that have scientific support from those that don’t. Here for example, is a study that distinguishes between certain medically-relevant differences (supported by the evidence) and cognitive differences (what the racists want you to believe). The racists want people to consider all these claims as equally valid—all good. Certain of my fellow progressives agree with the racists to the extent that we should consider all these claims to be equally valid, although with the idea that they should all be rejected. Treating all these claims as alike in their value seems to be a mistake because it puts racist pseudoscience on the same footing as research you can find on PubMed.
In 1992, I married a black woman secure in the knowledge that humans from all over the world are basically the same, and nothing I’ve learned since then has changed my mind about that. Despite whatever genetic differences there may be from one group to another, a man and a woman from any two places can have healthy, normal children together. The large differences among the “races” are socially constructed differences, while the biological differences are minor. My wife passed away in 2008.
In 1994 when our daughter was born, a nurse told me that she was physically advanced. I made some joke about my good genes, and the nurse responded by telling me that black newborns tend to be advanced compared to white babies. That response came as a shock to me because it violated expert opinion as I’d learned it. Since this observation contradicted my deeply held beliefs about “race”, I compartmentalized it. Despite the contrary evidence, I still believed that “races” were not just merely social constructs but in fact constructed out of nothing. Thanks to this compartmentalization, it took multiple lines of evidence from different sources and years of mental adjustment before I could see that Gould and Lewontin had simply been wrong. If some of my fellow progressives are angry at me for my views about genetics and human variation, I can sympathize with them because they are the views that would have infuriated me when I was in my 20s.
The other lines of evidence came from genetics and medicine. In medical research, doctors need to know what the biological facts are, regardless of politics. They have found real differences among different populations, although they’re not the sort of differences that racists wish they had found. For example, if you’re looking for a compatible donor for a bone marrow transplant, your continental ancestry* makes a difference. European-Americans are more likely to find a compatible donor among the pool of other European-Americans, and you can say the same thing for other groups. Researchers studying obesity have also found that people of different ancestries tend to carry fat on different parts of their bodies, so an overweight person of East Asian ancestry is likely to suffer ill effects at a lower proportion of body fat than someone of sub-Saharan ancestry.
Another line of evidence comes from genetics. With a sample of someone’s DNA, scientists can determine which continent or continents the person’s ancestry derives from. Personally, I’m northern European. In the 80s, I had been led to believe that human genetics was such a blur that we’d never be able to pinpoint someone’s “race” from their DNA (see “cline”). Now that we’ve mapped our genome, geneticists can identify not only someone’s continental/global ancestry but also which smaller ethnic group they belong to and in some cases which valley their ancestors lived in. For certain ethnic groups, such as East Africans, Uighurs, or Hazaras, geneticists can measure how much of their DNA comes from one continent and how much from another. East Africans represent an admixture of West Eurasian (“Caucasian”) DNA and sub-Saharan African DNA. Uighurs and Hazaras represent admixtures of West Eurasian and East Asian DNA. A close look at the features of people from these ethnic groups seems to confirm these ancestries.
As for Gould’s claim that there has been no biological change for tens of thousands of years, just the opposite is true. Cultural evolution has not replaced biological evolution but instead accelerated it. Domesticating milk-producing animals, for example, has led several human groups to independently evolve adaptations that allow them to digest milk sugar (lactose) in adulthood. Scientists have also identified an adaptation among Tibetans for living at high altitudes and an adaptation for diving among the indigenous Bajau of Indonesia. Gould’s outdated argument against the importance of “race” was that natural selection hasn’t operated fast enough to differentiate people of different continental populations. In fact, natural selection has operated so fast that there’s a new argument against the importance of “race”. Evolution has led to regional differences within each continent, contradicting the idea that continental populations (“races”) are homogeneous. Racists might want to talk about a single “white race”, but Europeans represent an admixture of three “races”: indigenous hunter-gatherers, Anatolian farmers, and finally cattle-herders from the steppe. Sprinkle in a little Neanderthal DNA, and obviously it’s impossible for any white person to be “purely” white. The same goes with any other “race”: they’re all amalgams. These amalgam genomes vary from one valley to the next, so continental gene pools play out as countless variations at the local level. No one of these variations is the “real” genotype or phenotype of that gene pool.
In addition to changing my scientific view of genetics as new evidence became available, I have also personally become more matter-of-fact about “race”. The views I hold today, as innocuous as they seem to me, would have angered the Jonathan Tweet of 1994, and I’m not surprised that they anger some folks today. So should we talk about the differences that researchers have identified? Maybe I’m wrong, but it looks like avoiding these findings doesn’t work. My daughter and I do not want to see racist pseudoscience gain any more ground, and the practice of avoiding the new evidence has evidently failed to keep the pseudoscience in check. If avoiding the evidence hasn’t worked, what can we do?
When I spoke at Seattle’s first March of Science, I said that evidence can bring us together. Charles Darwin looked at the evidence and concluded that humans all over the world are the same species, not separately created kinds as certain creationists had concluded. In my children’s book, Grandmother Fish, I coach parents to explain to their kids that we are one human race, all the descendants of “Grandmother Human” (see below). I’m heartened to learn that antiracist researchers have confirmed that teaching the facts of human variation can reduce prejudice. Certainly, some people who share my egalitarian ideals take exception to my approach to human biology, but I don’t bear them ill will. Their motivations are positive even if the way they treat me is negative. Twenty-five years ago, I would have agreed with their criticisms, and that perspective makes it easier for me to be charitable toward them than it is for them to be charitable toward me. My hope is that over the next few decades the power of evidence will lead us to greater agreement.
* AKA “global ancestry”
“If, as scientists, we fully abstain from laying out a rational framework for discussing human differences, we will leave a vacuum that will be filled by pseudoscience, an outcome that is far worse than anything we could achieve by talking openly.”
—David Reich, Who We Are and How We Got Here (2018)
Links
“Can Biology Class Reduce Racism?” by Amy Harmon. Experimental curriculum uses science to head off students’ racist intuitions.
‘The Native American/East Asian "race"’, using modern genetic science to debunk 19th-century racial categories.
* * *
“Race”: I put “race” in scare quotes because it doesn’t really exist according to its traditional understanding but there’s no widely recognized replacement term for groups that share continental ancestry. [EDIT: I asked around, and “ancestry” or “genetic ancestry” look like good terms. Link.] [EDIT: Also, “global ancestry”.]
Being Wrong: What it was like for me to be wrong about big ideas.
Speech at March for Science Seattle: Evidence can unite us.
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