This weeks edition of New Scientist magazine carried an article entitled “Scans prove there’s no such thing as a ‘male’ or ‘female’ brain” [1]. The article was inspired by a journal article published in the PNAS last month [2], which reviewed the scans of 1400 different people to see if there were specific differences in the neuroanatomy of the brains of men and women (i.e., are there ‘male’ and ‘female’ brains, or are the commonly accepted male/female differences just a myth, or a cultural, not biological phenomenon?)
According to the article, there is an “extensive overlap between the distributions of females and males for all gray matter, white matter, and connections assessed. Moreover, analyses of internal consistency reveal that brains with features that are consistently at one end of the ‘maleness-femaleness’ continuum are rare. Rather, most brains are comprised of unique ‘mosaics’ of features.” [2]
So essentially, there’s no strong biological basis for gender differences after all. “This means that, averaged across many people, sex differences in brain structure do exist, but an individual brain is likely to be just that: individual, with a mix of features. ‘There are not two types of brain,’ says Joel.” [1]
This news is a blow to one of Dr Leaf’s less renowned books, “Who switched off your brain? Solving the mystery of he said/she said” [3].
Dr Caroline Leaf is a communication pathologist and a self-titled cognitive neuroscientist. Her ‘he said/she said’ book is based on the idea that there are definitive characteristics of the male and female brain which define each gender. From her conclusion on page 211,
“Men and women are different. Both the physical anatomy and functional strategy of our brains are different. We can’t attribute this to social engineering, cultural norms or our up-bringing. We’ve been created different – it’s in our fundamental design. Our parents, our communities, and the cultural context of our childhood and adolescence certainly have a prominent developmental role in each of our lives. But your brain has been fashioned in a specific way that shapes your ‘true you’ long before any of these other factors have had the opportunity to exercise their influence on you.”
As a quick aside, this quote shows the confusion in Dr Leaf’s teaching. As I’ve discussed before in other blogs, Dr Leaf contradicts herself by claiming that our brain determines our gifts and our behaviours in some books (like ‘He said/she said’ and ‘The gift in you’) but then claims that our thought life controls our brains and our physical reality in the rest of her teaching. So which is it?
But this quote also sounds the death knell for her book, in light of the recent scientific evidence to the contrary. Which is a shame, since out of all of her books, this one initially seemed the most scientifically robust.
Even though the book is based on a now defunct theory, I wonder if the thrust of her book still holds true to a point. We’ve all been created to be different, and we should celebrate those differences and how they complement other people around us. It just so happens that those differences aren’t inherent to our gender, but to us as individuals, uniquely designed by God “for good works, which God prepared in advance for us to do” (Ephesians 2:10).
So, yes, the mystery of he said/she said has been solved, but not quite as Dr Leaf envisaged.
References
[1] Hamzelou J. Scans prove there’s no such thing as a ‘male’ or ‘female’ brain. New Scientist. 2015 Dec 5.
[2] Joel D, Berman Z, Tavor I, et al. Sex beyond the genitalia: The human brain mosaic. Proceedings of the National Academy of Sciences of the United States of America 2015 Nov 30.
[3] Leaf CM. Who swithced off your brain: Solving the mystery of he said/she said. Texas, USA: Inprov, Ltd, 2011.
Dr C. Edward Pitt 