Greg Laden posted a nice review of a traveling science museum exhibit on race and racism. His post touched on a couple of points of disagreement between him and the creators of the exhibit, but all the argument that followed was over this:

First, the parts we agree with: There is no such thing as race (biologically), race is a social construct used as a political and economic tool, even efforts to use race in a “positive” way such as in medicine or forensics are doomed to failure because of the lack of biological validity of the concept, and so on and so forth.

This brought out the racists, as has been the case every time I’ve seen a statement like this made, but unlike in the past, I got involved in the argument. I learned a lot doing so, and I want capture and summarize that here, for myself and others.

Definitions
These get to be pretty important in any argument like this, especially for avoiding accusations of ad hominem attacks. These are the relevant definitions from the Websters Third New International Dictionary of the English Language, Unabridged.

Racism: the assumption that psychocultural traits and capacities are determined by biological race and that races differ decisively from one another, which is usually coupled with a belief in the inherent superiority of a particular race and its right to domination over others. [emphasis mine]

Valid: based on distinctive characteristics of recognized importance: founded on an adequate basis of classification.

I emphasized “usually” in the definition of racism because belief in racial superiority is not necessarily part of racism, although it is important in explaining racism’s negative effects. It is, however, the piece that people who defend the concept of race focus on when you use the first part of the definition to classify them as racists.

The Argument for Race
There were four main arguments made for the biological validity of race:

1. Genetic testing allows for grouping by country of ancestor origin.
2. Race may not predict the things it’s been used to predict in the past, but it’s an important proxy for genetics in medicine.
3. Yes, assignment of humans to racial categories is an arbitrary procedure, but we use arbitrary names for parts of other continua. Why not race?
4. You’re just being PC, Marxist wankers.

I think we can ignore #4, but the rest were addressed in the discussion.

Where to Start
Most of the racists started with the assumption of race and told the rest of us to disprove it. However, as Greg pointed out, that’s the wrong base assumption. We don’t assume that each bird that we see that is slightly darker than its fellows or is missing a tail feather is a new subspecies. If we want to claim that they represent a group distinct from another group, we have to define the boundaries of the group and prove their validity.

We expect genetic variation. We expect changes in the frequency of alleles across types of environments, across distances from the point of origin of a mutation. Human history is in part a history of trade and conquest, so we also expect changes in frequency across trade routes and distances from trade routes, across distances from imperial centers.

The key word is “across.” As noted before, people trade and fight and have sex and produce offspring with their neighbors. Greg likened this to a game of genetic telephone. What you hear at any two widely separated points may sound distinct, but there is a chain of changes between them. We can divide up our players, but why?

The burden is on the person wanting to impose categorization to show that the categories are valid–both accurate and useful. The existence of a distinct genetic population of humans is not an impossibility, but what we know of human history makes it quite unlikely.

Genetics of Origin
The racists brought up studies that showed that, starting from a knowledge of the region of origin of a test population’s ancestors, researchers could find genetic markers that, in combination, could sort the test subjects into clusters by region of origin. This was given as evidence of the underlying genetic validity of race. There are three problems with these studies.

The first is a sampling problem. Remember that game of telephone? One of the racists in the thread suggested sampling whites from Sweden, blacks from Nigeria, and Asians from China. Researchers in one study cited excluded subjects who gave “other” for their race. If you cut out the parts of your sample that don’t unambiguously fit into your racial mold, it’s much easier to point to the remaining subjects as supporting it.

The second problem is related to how the genetic data was chosen. Researchers used a program for analysis that searched for sites among the hundreds sampled on the genome that could be used to sort the population into a specified number of groups. That means that sites that didn’t covary weren’t used in the analysis. Variation was again discarded on the path to finding distinct populations, and even then, the one of these studies cited in its entirety was not able to differentiate between two Asian groups without restricting their data further. Other studies that haven’t discarded data have found that there is much more variation within races than between them.

Third, nothing about these studies suggested that there were any real-world correlates of any note to the genetic sites used to separate the populations, thus failing to demonstrate any importance in the differences that were found. Relying on self-reported data on origin, they did not even show that the genetics they were testing correlated to any traits typically used to sort people into races.

Race for Medicine’s Sake
One of the more seemingly benign arguments for clinging to the concept of race is that it can provide a clue to underlying genetics that can be useful in diagnosing or treating disease. After all, we know that Ashkenazi Jews get Tay-Sachs and that Africans get sickle-cell anemia. Again, there are multiple problems with this argument.

Both Tay-Sachs and sickle-cell anemia are genetic disorders with well-defined mechanisms, but environmental factors play a role in many diseases. Many of the other disorders that are often linked to race, such as skin cancer and hypertension, do not have such well-defined causes. Limiting diagnosis and treatment advice based on race in these cases is risky at best.

Even among known genetic disorders, inheritance is not based on race as we know it. There are no races that all get one disease that no one else gets. The gene for sickle-cell anemia is adaptive in areas with high rates of malaria. This means that there are areas of Africa with almost no instance of the gene and areas of Europe and Asia with fairly high rates. Tay-Sachs is prevalent among one population of Jews but not others. It is also prevalent among Cajuns. French Canadians also have a higher than average prevalence, but the underlying genetics among Quebecers is different than among Cajuns, who share a mutation with the Ashkenazi Jews. As in the studies on population genetics, single genetic markers show very little correlation with race or point of ancestor origin.

Continua and Complexity
“Erm, okay,” say the racists, finally. “Maybe the underlying genetics do vary smoothly. That doesn’t mean they don’t vary. We use arbitrary names for other continua, like color. Why not for races?”

While this is once again starting from the assumption that race has validity–that it already measures something–and thus, the wrong question, it does raise a couple of issues that are worth talking about. Color, an example used in the discussion, is provocative. The underlying continuum is smooth, but we do use divisions of it, frequently and successfully, in communicating with each other. Why can’t we do the same with race?

The answer is complexity. To the extent that we agree on a definition of a name, saying that something is a particular color tells us what wavelength(s) it reflects or emits. What does race tell us? What is the underlying continuum that we’re measuring?

Of course, we can’t reduce humans to a single continuum of variability. We even have difficulty finding traits once considered to be racial traits that vary with geography in ways a racial model would predict. Skin color varies with average sun exposure as much as it does with any known pattern of migration. Analysis of skeletal remains, now and in the past, does not reliably indicate group identity. Facial features and body proportions are both too variable and too consistent across groups.

The continua that race tries to measure are not single, smooth gradations around the world. They don’t always follow the same paths, so that if we overlaid one trait on another, the resulting map would look somewhat like plaid but much fuzzier. A third overlay, accounting for just one more trait, would produce an even more muddled map. Where do we stop and still see anything that look like groups without the groups being larger than an extended family–or even an individual? We would have to reduce the number of traits to the point that we would only be measuring trivial differences between us.

Still No Answers
The question I kept asking during the discussion is, “What does race tell us?” It still goes unanswered after all the debate. If someone wants to claim that race has biological validity, race has to not only be based on biological measurements that distinguish the categories used, which current racial classifications are not. It also has to tell us something about the biology of race that is nontrivial. Importance is a critical part of the definition of validity.

After this discussion, I’m much better aware of what race does not tell us. I’m still waiting to be shown what it does.

I’m not sure what’s happening this year. Whatever it is, it isn’t what happened four years ago, or eight, or more. The things that everyone knows about politics and elections are turning out to be false. This year.

Joe Biden and Sarah Palin had a debate. Everyone knew that the expectations had been lowered so far for Palin that it would be hard for her to lose. She was folksy. Biden spoke in long words and obscure allusions–the kiss of death. Everyone knows that should have cost him.

People ate it up. Biden won the debate.

Locally, Senator Coleman has been running nothing but attack ads against Al Franken. Everybody says they hate them, but everybody knows they work. So he runs them.

Except this time. Coleman is down in the polls and has decided to withdraw the ads. He says it’s because we can’t afford to be negative with the economy in shreds. It’s because the ads are costing him votes.

I’m not sure what’s going on. Voters are behaving differently, unprecedentedly–dare I say rationally? I’m completely confused, but I have only one question.

Can we keep it?

Update: As usual Comrade PhysioProf says far more succinctly, even with all the swearing.