A fascinating paper about sex differences in the human brain was published last week in the scientific journal Cerebral Cortex. It’s the largest single-sample study of structural and functional sex differences in the human brain ever undertaken, involving over 5,000 participants (2,466 male and 2,750 female). The study has been attracting attention for more than a year (see this preview in Science, for instance), but only now has it been published in a peer-reviewed journal.
For those who believe that gender is a social construct, and there are no differences between men and women’s brains, this paper is something of a reality check. The team of researchers from Edinburgh University, led by Stuart Ritchie, author of Intelligence: All That Matters, found that men’s brains are generally larger in volume and surface area, while women’s brains, on average, have thicker cortices. ‘The differences were substantial: in some cases, such as total brain volume, more than a standard deviation,’ they write. This is not a new finding – it has been known for some time that the total volume of men’s brains is, in general, larger than that of women’s, even when adjusted for men’s larger average body size – but all the studies before now have involved much smaller sample sizes.
Does this paper have any implications when it comes to men and women’s intellectual abilities? The answer is yes, but they’re not clear cut. (To read more, click here.)