Genes and culture

Reading half a dozen reviews of Nicholas Wade's new book "A Troublesome Inheritance" had almost reduced me to despair of ever finding one that didn't get stuck in the long-running "tastes great, less filling" quarrel between nature and nurture, or in sterile quibbles over whether the word "race" has any meaning.  (I can't say for sure when red becomes orange and orange becomes yellow, but I know that colors can be usefully distinguished.)

This New York Books review, amusingly entitled "Stretch Genes," avoids the usual excitable excesses.  Wade's book sounds like an interesting romp through theories about how traits like willingness to trust non-kin, or ability to delay gratification, can profoundly affect the structure of civilization.  It also sounds like an inexplicable effort to attribute to genes a number of global differences that could as easily be attributed to culture.  Wade looks, for instance, at the hesitance of some Southeast Asian cultures to adopt successful strategies from Chinese immigrants.  If it were only a matter of culture, he wonders, why wouldn't people readily adopt the new strategy as soon as they observe its success?  It must be genetic.  Or . . . could there maybe be some huge non-genetic hurdles to adults' ditching one culture and adopting another that seems to offer an advantage in one sliver of life?

There are fascinating studies involving identical twins separated at birth.  They are almost the only line of inquiry that I find persuasive on the knotty problems of disentangling nature from nurture.

4 comments:

  1. Colors exist on a continuum, i.e., how our brains perceive a small portion of the electromagnetic spectrum. Since these waves are distinguished by a mathematical regularity in length, we can come up with some pretty solid rules for distinguishing colors if we want to do so: given the length of the spectrum we can see, and the generally agreed seven colors, one could simply make a mathematical division.

    Race doesn't occupy any similar position. It's hard to say anything genuinely scientific about it. We can certainly talk about how (relatively) isolated groups of people have developed genetic differences over time, and indeed it would be hard to imagine -- humans being a kind of animal -- that this wasn't the case.

    Nevertheless race science has been at best the kind of empirical taxonomy that often produces the sense of something real where nothing is real. Aristotle's biological works are often of the same kind: he gives an account of the camel that is insightful in a way, i.e. that it recognizes that the camel has certain features different from other similar creatures because of facts about how it interacts with its environments and food sources. But these are explained in terms of an assumed elemental theory that tries to account for what the camel did with the "earth" that other similar creatures use for front teeth or horns (the answer is that it has a harder palate, the better to eat thorny scrub).

    Of course the real reason has something to do with genetics -- just the thing this author would like to talk about as being explanatory for some human differences. And of course they must be, sometimes, somehow, because we aren't that different from camels.

    Race at its best seems like the elemental theory -- something that was assumed, at a particular point, to help sort out some empirical observations but which proves to be unreal. At best, I say: obviously the Enlightenment was only too happy to bend its assumed content in ways that justified its newfound source of extraordinary wealth, the trans-Atlantic slave trade.

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  2. the knotty problems of disentangling nature from nurture.

    I'm not sure we can, except artificially, in the manner of breaking complex problems, often arbitrarily, into simpler constituents for easier inquiry.

    Evolution is a feedback loop between nature and responses to nature (at one remove, it's life talking to itself), and that acts at the genetic level. Even our cultural adaptations lead to genetic responses as those cultural adaptations lead to changes in environment, with resulting changes in evolutionary pressures, which leads to cultural and genetic responses,....

    See, for instance, the use of grains as major components of our diet, and the (as yet "incomplete") genetic adaptation to grains, with some humans able to handle the glutens (for instance) as major inputs to our gut and others not yet. Or lactose intolerance, from so far incompletely adapted at a genetic level to the move from mother's milk to cow's milk.

    Look for education as a third input to the evolution feedback loop.

    Eric Hines

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  3. On the matter of race and genetics, I see one of two possible outcomes to a properly objective and scientific analysis of our genetic code. On the one hand, the result would be there is no genetic difference; "racial" differences are entirely nurture- (and education-) driven. Or, we might learn that this genetic code defines this race, and that genetic code defines that race. With the line between the two drawn wholly arbitrarily between two base sets adjacent to each other on some sort of genetic spectrum.

    However.

    Distinguishing among colors, even down to an arbitrarily drawn line separating this frequency/color from frequency+1/color (from a spectrum of wavelengths also arbitrarily separated one from another, unless we're getting quantum), can have some value.

    What value is there in defining this race from that one, especially given the moving target nature of the genetics due to interbreeding, that would justify the cost (along any dimension)?

    Eric Hines

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  4. Who cares about defining races? The fact is that genetics are important in many areas, and human beings necessarily come in broad groups genetically, because there has never been a simultaneous worldwide reshuffling of everyone's genes. There's no need to over-emphasize the differences, but there's also no reason to be afraid to acknowledge them. "Race" is usually a rough, short-hand expression for a certain amount of common ancestry. I don't need to be able to define sharp boundaries for an ancestral group in order to notice that it has huge effects on all things gene-related, from vitamin D mechanisms to sickle-cell anemia to the ability to metabolize sugar, grain, alcohol, and lactose.

    You'd be hard-pressed to find someone more impatient than myself of the tendency to jump to conclusions about individuals on the basis of their belonging to a more or less differentiated group. But that doesn't mean I have to make myself blind to statistical differences among groups.

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