Race, genes, and intelligence

2007-11-18 15:29 - Links

According to twin studies, 50 to 90 percent of variation in head size and brain volume is genetic. And when it comes to IQ, size matters. The old science of head measurements found a 20 percent correlation of head size with IQ. The new science of MRI finds at least a 40 percent correlation of brain size with IQ. One analysis calculates that brain size could easily account for five points of the black-white IQ gap.

It was quite recently that I saw a documentary on TV that was quick to state that head size did not directly affect intelligence. Their example was that men are not inherently more intelligent than women, just because they happen to be larger. This, however, is what might be a relatively controversial article claiming that brain size does in fact play a distinct role in intelligence, as one of the genetic factors that play out in smarts. So what's the truth?


2007-11-19 11:11 - kathaclysm

Well, men and women do have the same average score on IQ tests, (I can't find anywhere to cite that, but I'm pretty sure the average is the same, just the distributions are different). And I actually knew a girl with literally only half a brain, and I just thought she had a physical disability (half her body was partially paralyzed) till I saw her on the news: http://www.nbc10.com/health/4563166/detail.html

So I'm always skeptical about brain size & intelligence... I think, like other parts of the body, it's not how big it is, but how you use it that counts most.

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