James Flynn says:
Two twins raised apart, thanks to having slightly better genes than average, would both get into increasingly privileged environments. Both would get more teacher attention, would be encouraged to do more homework, would get into a top stream, and by adulthood, they would both be far above average. Moreover, thanks to their identical genes, their environmental histories would be very similar.
He's attacking the idea that the 80% correlation between IQs for twins raised apart implies that genetics can play a strong role in determining IQ. But the way he phrased it is interestingly discursive. A more compact way to say that is "Genes for intelligence are expressed through the environment." Which is a way of illustrating the absurdity of his view, because the above paragraph could also refer to those genes being expressed in brain size and structure. Imagine: "Twins raised apart have a slight IQ advantage, which tends to cause them to think more complex thoughts than most, which causes their brains to develop in a way different from most. Thus IQ is not caused by genes. It's caused by things genes cause."
I'm not sure what Flynn is doing here, but I'm pretty sure it isn't science.
Comments (1)
Well, there's what he might be THINKING but not explaining explicitly, and there's what he's actually saying.
When children are put up for adoption, the candidate households are customarily screened in a variety of ways--not just any household is likely to receive the children. And this helps set up the pattern in which the two twins' environments "tended to be similar for identical twins when raised apart."
But I'm not sure that anyone in this society is often really doing science when they start talking about topics like IQ and inequalities of achievement. It's very hard to do rigorous science on these topics, and the problems with accommodating the prejudices of the locals, whatever directions those prejudices might already lean, delivers the final kick in the pants. This applies whether the prejudices are the Harvard social science faculties', Jesse Jackson's, or just those of some guy who wants to be told that the reason he is privileged and wealthy is because he's smarter and better than everyone else in as fully general a way as possible. (Not to imply that you are necessarily a representative of the latter group, but they do exist.)
Posted by Anon | January 20, 2008 11:14 PM
Posted on January 20, 2008 23:14