June 18, 2005

If Stephen Jay Gould were alive today, he'd spinning in his grave

Gould devoted a lot of space in his 1981 bestseller denouncing IQ research The Mismeasure of Man to claiming that 19th century researchers into the relationship between brain volume and smartness cooked their data. For some reason, lots of people have considered this a crushing rejoinder against 21st century IQ science. In truth, the old scientists didn't cheat, but even if they did, that doesn't seem much more relevant to today's research than asserting that modern astronomy is fraudulent because astronomers used to believe the sun went around the earth.

Well, it turns out that Gould was not only irrelevant, but wrong -- the old physical anthropologists were right about the correlation between brain size and brainpower.

"Big-Brained People Are Smarter" says researcher Michael McDaniel of VCU:

The relationship between brain volume and intelligence has been a topic of a scientific debate since at least the 1830s. To address the debate, a meta-analysis of the relationship between in vivo brain volume and intelligence was conducted. Based on 37 samples across 1530 people, the population correlation was estimated at 0.33. The correlation is higher for females than males. It is also higher for adults than children. For all age and sex groups, it is clear that brain volume is positively correlated with intelligence.

That's not a huge correlation, but for female adults it is 0.41 and for male adults it is 0.37. It's usually said in the social sciences that a correlation of 0.2 is low, 0.4 is medium, and 0.6 is high.

These brain volumes are typically measured with MRIs or the like. The correlation between IQ and hat size is quite low, although it is positive.

The best-known proponent of the IQ-brain volume link in recent years has been J.P. Rushton, which would drive Gould even more crazy.

Gould was a classic example of the kind of charismatic egomaniacal workhorse scholar who has done so much damage going back to Marx and Freud. You can get quite rich these days telling the intellectual class what it wants to hear. From a news report on the malpractice suit filed by Gould's widow against his doctors:

The lawsuit does not specify the damages being sought, but says that Dr. Gould earned $300,000 a year from speaking engagements alone, that "a seven-figure income was his norm" and that when he died he was about to enter into a book contract for more than $2 million.


My published articles are archived at iSteve.com -- Steve Sailer

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