John Mitchinson explores how our brains reflect our lives not our genitals
Sign up for our weekly Behind the Headlines email and get a free copy of Byline Times posted to you
John Gray’s Men are from Mars, Women are From Venus was the highest-selling non-fiction title of the 1990s.
With sales of over 15 million copies across 40 languages, it created its own publishing ecosystem: Why Men Don’t Listen and Women Can’t Read Maps; Why Men Lie and Women Cry; Why Men Don’t Have a Clue and Women Always Need More Shoes; Why Men Like Straight Lines and Women Like Polka Dots; Men are Clams, Women are Crowbars.
The Mars-Venus industry offered people a quick and easy way of understanding themselves based on some dubious science, much of it backed up by the seductive visual allure of brain scans – the modern equivalent of the phrenologist’s plaster cast skull.
Increasingly, the science suggests that any difference between male and female brains has more to do with nurture than nature.
In 2019, neuroscientist Gina Rippon took on these pervasive myths and misconceptions in her book The Gendered Brain. “Beliefs that biological sex bequeaths a fixed and different portfolio of brain-based skills to males and females become entrenched in the public consciousness,” she observed. “In a cycle of self-fulfilling prophecy, such beliefs drive how children are reared and educated, form the bases of different attitudes to and expectations of females and males, and afford them different experiences and opportunities.”
Our genitals may not change, but our brains do.
One of the most celebrated studies to demonstrate this was run by UCL in 2000 and followed a group of 79 trainee London taxi drivers and 31 non-taxi drivers, recording snapshots of their brains through MRI scans over four years of training. The results were striking – after four years, the drivers who had passed the Knowledge all had a significantly greater volume of grey matter in their posterior hippocampus (essential to learning and memory) and a greater volume than either the drivers who had failed or the non-taxi driver controls.
It remains one of the most significant demonstrations of how experience can directly affect and change the shape of the human brain. In other words, brains reflect the lives of their owners far more than they do their sex.
Last year this was unambiguously confirmed by a comprehensive synthesis of three decades of research into human brain sex difference findings published by Lise Eliot, Professor of Neuroscience at the Rosalind Franklin University in Chicago, with the take-no-prisoners title of ‘Dump the “Dimorphism”’ (‘dimorphism’ is the scientific term for something that has two forms, from the Greek ‘two-shaped’).
The findings of Eliot’s survey were unambiguous: despite clear behavioural differences between men and women, sex and gender differences in the brain are small and inconsistent, once individual brain size is accounted for. In other words, male and female brains are effectively the same in structure and function.
But what about the ‘clear behavioural differences’ between the sexes?
Eliot has a helpful line on that too: a picture is emerging not of two brain types nor even a continuous gradient from masculine to feminine, but of a multi-dimensional “mosaic” of countless brain attributes that differ in unique patterns across all individuals.
This ‘mosaic’ is borrowed from a now celebrated piece of research from 2015 conducted by Professor Daphna Joel at Tel Aviv University. Her study used scans of 1,400 men and women’s brains analysing the volume, connections, and other physical characteristics. She then selected 10 areas of the brain where the samples showed, on average, the largest physical differences between male and female brains (including both hippocampi and the superior frontal gyrus).
What you would expect is that this data would reveal a continuum – with male brains ranging towards the male end of the scale and female brains towards the other. In fact, only one in 10 of the brains studied ended up skewed in this way. Most were ‘mosaics’ – the brain architectures typical of men were also common in women and vice versa.
Joel’s conclusion is persuasive – that we should widen our social norms from “the common belief that the possession of female or male genitals should be accompanied by a specific experience of the self and a specific set of psychological characteristics, preferences, and behaviours, and advocate, instead, a culture that celebrates the enormous human variability”.
At the beginning of the 19th Century, we embraced phrenology because it seemed to offer a new way of looking at ourselves and we rejected it when the science didn’t back it up. After centuries of assuming that our brains somehow mirror our genitals, the science is telling us that it’s time to come up with a better working model.
Sex and gender will always be important variables, but it seems they aren’t necessarily the dominant ones when it comes to the multi-dimensional mosaic of attributes that each of us carries in our heads.
John Mitchinson is a writer and publisher and co-founder of Unbound, the world’s leading crowdfunding platform for books. He was one of the founders of BBC’s ‘QI’
OUR JOURNALISM RELIES ON YOU
Byline Times is funded by its subscribers. Receive our monthly print edition and help to support fearless, independent journalism.