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

DOI: https://doi.org/10.1177/0956797621996664

Commentary

Although men and women differ in brain structure and behavior, and sex differences in brain and behavior may be related, women and men are subject to different social and cultural norms.

The researchers overcame this challenge by investigating the variability of brain structure by gender for each sex.

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

We found a weak association between these brain and behavioral differences, caused by brain size.

These brain and behavioral differences were also shown to be 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.