The original paper was published in the journal Intelligence. (Subscription required.)
To determine if there was a link between gender and intelligence, and perhaps between brain size and intelligence, Rushton and a colleague analyzed the Scholastic Aptitude Test (SAT) scores from 100,000 17- and 18-year-olds.
When Rushton and colleagues weighted each SAT question by an established general intelligence factor called the g-factor, they discovered that males surpassed females by an average of 3.6 IQ points.
In rebuttal, Bruce Braken, a psychologist at the College of William and Mary in Williamsburg, Virginia says the study didn’t take other factors into consideration.
“I believe that the differences probably lie in the variables they hadn’t considered,” Bracken said.
One plausible explanation is that more females than males decide to go to college and thus take the SAT test. The study did in fact include about 10,000 more females than males.
“This suggests that more males are deciding to do something else,” Bracken said. “It may be that the males who would not have scored as high on the SAT chose not to take it, and they chose another route.”
A more reliable study, he said, would be to match each male with a very similar female and then compare the results.
We’re not really sure what this blog says about gender differences in intelligence. We’re pretty sure it says something about Multiple Personality Disorder, though.