History Matters (and so does the environoment) — Steven Pinker/Personal Genomics dept.
Steven Pinker has made something of a splash with his account of confronting his personal genome, published in the NY Times magazine last week. The article is interesting, though Pinker’s hint of nervousness about just how much he wants to know of himself genetically gives it a slightly odd list to port.
There was also a problem, IMHO (humble, and without professional expertise, too) with the presentation of the article. Though Pinker was careful to undermine from time to time what he recognized as one of the fascinations of personal genomics — that “the human mind is prone to essentialism — the intuition that living things house some hidden substance that gives them their form and determines their powers” — the piece still teetered on a kind of 1980s “We’ve discovered the gene for X!” hoopla.
Much of that impression was conveyed by the photos that accompanied the print version of the article, with headshots of Pinker captioned with the trait identified within his genome. Partly, though, it derived from Pinker’s own ambivalence, as he acknowledged the pitfalls of essentialism in a genome in which so much of the information is not devoted to protein coding, and yet wrote sentences like this:
For some conditions, like Huntington’s disease, genetic determinism is simply correct: everyone with the defective gene who lives long enough will develop the condition.
This is true, of course, and yet…the genetic signature of Huntington’s disease involves the number of repeats of a short section of the genetic code, just three bases or genetic “letters,” associated with the Huntingtin gene. There is a number of repeats below which someone is not at risk for the disease — less than 27 copies — and a number above which disease essentially always occurs — 39 repeats and up. In the middle, the issue is more ambiguous, and a repeat total in that range may result in late onset of the disease, or even a progression to overt symptoms that is so slow that the affected individual dies of some unrelated cause before the production of the damaging form of the Huntingtin protein actually does enough harm to notice.
What governs the number of repeats is unclear; it is not, seemingly a matter of pure inheritance. Masha Gessen in her excellent Blood Matters tells the story of two brothers at risk for the Huntington gene. One develops symptoms early, gets tested, and receives confirmation that he possesses the gene with sufficient repeats to account for his relatively early onset of the disease. The other brother, who presumably inherited the same gene from the same parent, possesses an intermediate number, and may or may not end up with symptomatic Huntington’s at some later point in his life.
What does this all mean? That even in cases where the overwhelming effect of heritable genes is obvious, where possession of a given form of genetic information directly correlates with a particular observable trait, there are processes involved in the replication and inheritance of that information that produce variation.
I am no biologist, so I’ll defer here to John Maynard Smith, with whom I had the good fortune to have a conversation the one time we met, a few years before he died. He emphasized what I don’t think has seeped deeply enough into the popular understanding of modern genomics. In his phrase, (from memory), the environment for a gene begins at the chromosome.
That is, the genes that actually code for a protein do not do their work or move from generation to generation in a vacuum. Rather they exist in a physical environment that begins with its most immediate context — the DNA that exists surrounding coding regions — and the extends outward through the structure of DNA and other organic material that makes up the chromosome; the nucleus of a cell; the cell as a whole and so on and on and on. Things happen at each level of organization and between them that can affect what happens when the rubber hits the road and a protein gets made.
All of which to say is that even though Pinker certainly did not claim that genes are destiny in any crude way, his article still falls into a tradition that I do not think has fully caught up with the richness and the complexity of modern genetics and cell and organismic biology.
That said, the other matter that made my antennae twitch in Pinker’s article came in this paragraph:
Though the 20th century saw horrific genocides inspired by Nazi pseudoscience about genetics and race, it also saw horrific genocides inspired by Marxist pseudoscience about the malleability of human nature. The real threat to humanity comes from totalizing ideologies and the denial of human rights, rather than a curiosity about nature and nurture.
I agree with the last sentence (though I’d hardly say that it covered the sum of threats to humankind), but the claim that the genocides perpetrated by Marxist regimes are an example of blank-slate ideology gone very wrong is problematical on two levels.
First, it is simply wrong. For example Stalin’s war on the Kulaks — well-off peasants/farmers — treated Kulak resistance to collectivization as a symptom of an inherant, non-malleable quality, the class identity of the offending farmers. Similarly, Mao’s campaign against landlords (and others) immediately after the 1949 victory of the Chinese Communists, identified class and or occupation as a kind of original sin from which there could be no return. The same basic notion underlines the horrors inflicted on class or educational level by other regimes.
Of course, in China and the Soviet Union, exterminations justified by the identification of a human stain that needed to be eradicated to open the possibility of forging a new Communist humanity had roots that have nothing to do with a real commitment to either essentialism or a blank slate view of humanity — though at different stages of the process, both ideas were invoked. Rather they were all about power and resistance.
But at the same time, any finer grained look at what happened in the state-massacres of the 20th century does not support the simple-minded notion that as much or more harm was done to human beings through a commitment to a false perfectability of humankind as as was done through a commitment to a false notion of ineradicable genetic defects in particular groups. Essentialism was an integral part of both Nazi and Communist murders.
And that leads to my second objection to what I see as Pinker’s false equivalence of two evils. It isn’t just that he admits no complexity to the history; it is that the moral argument he seems to be making is itself highly suspect.
The real question Pinker avoids here isn’t whether evil comes to the world down multiple avenues. It is whether or not evil flows from a given cause, and if so, what can be done about it.
That dictators have used many justifications to treat other human beings as things rather than moral ends in themselves does not let you — or Pinker — off the hook on the specific issue of the misapplication of genetic ideas to divide humanity into those worth keeping and those it is permissable to destroy.
It is therefore also true that the pursuit of genetic knowledge, of that part of the human condition that is genuinely in ourselves, and not in our circumstances, needs to be concerned about the moral and ethical hazards raised by the research.
Of course, the field(s) are in fact acutely aware of this, as is Pinker himself, no doubt. But that he dredged up the old shibboleth that the Commies did it as his first response to the anticipated objection against the spectre of genetic determinsm betrays to me a kind of weariness with the argument.
I can understand that too — plenty of heat and not much light has been poured on this argument often enough. But it is still a bit of rhetorical sleight of hand, and it’s been popping up a bit in defenses of the new genomics. And that can’t be a good thing.
Update: I omitted thanks due to Abel Pharmboy and Janet Stemwedel, each of whom looked over sections of the post above to help preserve me from my own ignorance. Any errors that remain are, of course, all mine.
Image: Giotto, “The Massacre of the Innocents,” 1304-306