Are sex differences in human brain structure associated with sex differences in behavior?

First published July 29, 2021 Search in PubMed in Research Articles

https://doi.org/10.1177/0956797621996664

Commentary

It has long been said that the brain structure of men and women causes them to behave differently, and that sex differences in behavior are related, but they are subject to different social and cultural norms for men and women.

The researchers overcame this challenge by investigating the variability of brain structure by each gender. The Queensland Twin Imaging Study (n = 1,040) and the Human Connectome Project (n = 1,113), based on average gender differences in brain structure and behavior, obtained data-driven measures of individual differences along male and female dimensions of brain and behavior, respectively.

We found a weak association between these brain and behavioral differences, caused by brain size, which also suggested that they are moderately heritable.

The findings suggest that sex differences in behavior are to some extent related to sex differences in brain structure, but are caused by differences in brain size, and that causality needs to be interpreted with caution.