At the beginning of the year, a Article Liz Elliott and colleagues at Rosalind Franklin University in Chicago reviewed dozens of studies documenting brain differences between the sexes, and after considering size (body) differences between men and women, concluded that the observed brain differences were negligible.

At the same time, My team Inside Department of Cognitive Studies Of ‘ENS-PSL Was in the process of publishing the results of a large brain imaging study, which yielded different results. This prompted us to write and publish Reference In Liz Elliott’s article, we highlight how our results questioned their conclusions.

Our study had a broader goal, which was to document neuroanatomical variations in the general population. It is based on a group of names UK Biobank, Contains extensive medical, biological, and social data on 500,000 British adults. Of these, 40,000 underwent brain MRI scans. Therefore, our study does not have the limited reliability of most previous studies. In fact, this is the largest study ever published on brain gender differences.

What did we find?

First, while it is true that brain size is related to body size, it is not true that size differences fully explain brain size differences between the sexes. As shown in the image below, even at the same size, men have an average larger brain than women.

Second, considering the differences in overall brain size, it is not true that there is almost no difference in the size of brain structures between men and women.

Many of them are present throughout the brain. Of the 620 brain regions we analyzed, about two-thirds (409/620) had significant differences between males and females, with about half as large and half as large as males. The figure below shows the distribution of these differences.

Clearly, brain areas have very different dimensions between men and women. But many areas show small statistical differences. Clearly, they do not exist, nor can they be reduced to differences in the total volume of the brain. Although the brains of men and women are broadly similar, they are also slightly different proportions, beyond the total size difference.

If these results contradict the claims in Elliott’s article, it is important to point out that they do not. They say nothing about the causes or consequences of these differences. The rest of the scientific knowledge in neuroscience currently does not allow to fill these gaps.

Factors that trigger these brain differences between the sexes

Are they genetic components (X, Y chromosomes)? Hormonal differences, early or late? Environmental differences, especially in the way humans are raised and treated differently according to their gender? A combination of all three? Some people rush to confirm that these differences are clearly innate and that others can only learn them.

In any case, these people are far ahead of what scientific knowledge can tell. There is good reason to believe that genetic, hormonal, and environmental differences may contribute to such differences. But at present no one is able to clarify their relative contributions and the exact mechanisms involved.

Finally, what are the consequences of these brain differences? Do they make a difference in the cognitive functioning of men and women? We do not know. Although there are relatively strong cognitive differences between men and women, our current understanding of the brain base of these cognitive differences is close to zero. Although the size of the brain Associated with intelligence, A significant difference in brain size between men and women is very close between the two sexes causing a similar difference in IQ scores. In general, no brain difference between the sexes supports the sexual stereotypes.

In our state of ignorance, it would be prudent to avoid too much speculation about the causes and consequences of brain differences between the sexes. But it is time to abandon the discourse that systematically denies the possibility of the existence of these differences, because it is now clear that this discourse is wrong.

To get more details about this study, you can consult This article.