I wanted to respond to one of the comments from a previous post, because it’s a reasonable argument that I come across fairly often:
I’m not sure any anthropologist would disagree that there [are] genetic similarities within groups of people and variations between groups of people. The difficulty comes in saying what “races” are. For example, are Jewish people a race or an ethnicity? Jews like me share many cultural similarities with each other, and we’re certainly more vulnerable to Tay–Sachs. But, I share very few physical similarities with a Semitic Israeli-Jew or a Ethiopian Jew. Race is a very complicated issue that has more to do with social conditions than genetic variation.
According to this line of thinking, anthropologists basically agree with me: There are genetic differences between races (or “populations” or “groups”), but the way we classify races has a lot to do with politics, culture, etc.
The problem is that this is not what many anthropologists actually argue. Rather, they use the inherent subjectivity of racial classifications to undermine the idea that there are any significant race-level genetic differences at all. Take, for example, this comment from the AAA’s recent statement:
Science lays bare popular myths that races are distinct biological entities and that sickle cell, for example, is an African-American disease.
The first assertion emphasizes the inherent subjectivity of racial classifications; the second makes a case against a race-level genetic difference. Both are straw men.
Regarding the first, no serious contributor to this debate says races are “distinct”; that could be the case only if interbreeding were impossible (in which case they’d be species, not races). If you bear this in mind, it actually is possible to classify most people based on only a DNA sample.
Regarding the second, no one says that sickle cell is an African-American disease; rather, it’s disproportionately an African one. You’d think a statement about race from a leading anthropological association would be a little more careful with its terms — and once you correct the terms to eliminate the straw man, the assertion is simply false.
The genetic variant that causes sickle cell is an evolutionary response to malaria (having one copy makes you resistant to malaria, but having two copies gives you sickle cell). One place where malaria is common, of course, is Africa. As a result, people of African descent have much higher rates of sickle cell than, say, people of Western European descent. (This is the biggest reason that American slaves were purchased from black slave traders rather than captured by whites. As Thomas Sowell put it, “a white man was more likely to catch malaria in Africa than to catch slaves himself.”)
To get technical, the variation is a single-nucleotide polymorphism called rs334. The HapMap Project has data on it for four populations: whites from Utah, Han Chinese, Japanese, and Yoruba from Nigeria. Of the roughly 150 Utahns, Chinese people, and Japanese folks HapMap tested, exactly zero carried the sickle-cell gene. Of the 60 Nigerians, 14 did. That’s what “science lays bare” about sickle cell and Africa.
We see this also when it comes to more controversial arguments. For example, the 1994 book The Bell Curve argued that it was “highly likely” that genetic differences cause part of the black-white IQ gap. In my view, this argument jumped the gun by at least a quarter-century: We won’t know for a while which genetic variations contribute to IQ and how those variations differ between races, and the alternative way of investigating this question — trying to “control” for other explanations statistically — isn’t particularly effective.
But rather than making the case for agnosticism, lots of critics claimed that the book’s argument just couldn’t be true, on the grounds that race is just a social construct. That’s not an argument you can make if “race is just a social construct” leaves room for the fact that “there [are] genetic similarities within groups of people and variations between groups of people.”