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March 06, 2005

An explication of assumptions

The Conflict Within - The Left's Version of Creationism has wended its way back and forth over the general path of the topic, but in the process, I think various issues have been confounded. So, this post is simply a review, or, an attempt to make explicit what I believe are background working assumptions (regular readers can probably skip this post).

First, I think there are various categories or types of thinking when it comes to the intersection between biology and the human sciences:


  1. Blank slate: which basically means that the only preprogrammed or primed aspects of our nature are bestial impulses like hunger or elimination.
  2. Operational Blank Slate: An admission that some aspects of our complex behavorial functioning are biologically shaped, bounded or rooted, but a declaration that the complexity of the phenomena and upstream variables defy analysis.
  3. Evolutionary Psychology: An acceptance of broad human universal tendencies, excepting (usually) sex differences. In other words, the loci which influence our behavior are nearly monomorphic so that one allele is exhibited in frequencies approaching fixation (100%). This mentality tends to reject intergroup differences and neglects individual (intragroup) differences.
  4. Behavior Genetics: An acceptance of salient individual differences which shape predispositions and life path probabilites. In this case, loci are not monomorphic, and two different polymorphisms, allelic variants, tend to result (on average) in different behavorial expressions.
  5. Human Biodiversity: An acceptance of different frequencies of alleles that give rise to different behaviors in different groups. That is, despite overlap, the frequency distributions of various polymorphisms vary from group to group, ergo, their average response to the same environments might also vary.

This is grossly simplistic, and I've focused on behavorial aspects so as to emphasize the most controversial elements of human biodiversity, I suspect that a far greater number of people are open to accepting human biodiversity's relevance in the context of tissue rejection than they are when it comes to intelligence or personality. In any case, on last three points, each is nested within the other when it comes to affirmation of relevance, so if you accept human biodiversity, you tend to accept behavior genetics and evolutionary psychology, and if you accept behavior genetics you tend to accept evolutionary psychology. But, the arrow of paradigm acceptance does not flow the other way. The main promoters of evolutionary psychology, John Toobey and Leda Cosmides, tend not to accept the salience of human biodiversity, and offer behavior genetics only benign neglect. Similarly, behavior geneticists, whatever their personal views, tend to avoid broaching human biodiversity, though the latter seems like a plausible implication of the former.

But when it comes to public debates that are politicized, the five groups tend to compress themselves into a dichotomy, so that individuals who espouse the first two propositions act as if they agree on points of substance, and, they treat those who espouse the last three propositions as if they were in one camp. The reasoning is simple: the small minority of individuals who are willing to publically espouse the salience of human biodiversity are far easier to denounce and rebutt than those at the biological antipode who focus on human universals. Most of the particulars in the original sociobiology controversy did not give much thought to human biodiversity (the exception was Bernard Davis, who was a supporter of Jensen). The same issue crops up in the later evolutionary psychology controversies, as some of the main proponents of the paradigm made explicit and grand gestures against human biodiversity, but their opponents nevertheless termed them "racists" or "Social Darwinists." The case with behavior genetics is far more muddled, and frankly the connection between it and human biodiversity is more transparent so "demonization" is not nearly as rhetorically contrived.

But the whole point of it is that people like Richard Lewontin are not insufferable because they reject human biodiversity, in a "strong" form most intellectuals reject it out of hand, rather, it is because they reject evolutionary psychology by attacking human biodiversity! They know very well that there is some confirmation bias in favor of evolutionary psychology from the general public (it "makes sense" to most people), so they want to hitch its wagon to something that the public couples with rejection bias. This is politics, not science, and it makes good faith discourse rather difficult.

Let me finish with a quote from the Lingua Franca piece that Jason linked to a few months ago:


Lewontin, who married his high school sweetheart and can to this day be seen walking hand in hand across Harvard Yard with her, takes a much harder line. "I'm a man, and I don't go around screwing young girls," he says. "I'm human, and so I have to be explained."

This, from a man who has an M.S. in mathematical statistics.

Posted by razib at 11:45 AM