However much we’d like to think of gender as a social construct, science suggests that real differences do exist between female and male brains. The latest evidence: a first-of-its-kind European study that finds that the female brain can be drastically reshaped by treating it with testosterone over time.
Research has shown that women have the advantage when it comes to memory and language, while men tend to have stronger spatial skills (though this too has been disputed). But due to ethical restrictions, no study had been able to track the direct effect that testosterone exposure has on the brain—until now. Using neuroimaging, Dutch and Austrian researchers found that an increase in this potent hormone led to shrinkage in key areas of the female (transitioning to male) brain associated with language. They presented their findings at last week’s annual meeting of the European College of Neuropsychopharmacology in Amsterdam.
For the study, researchers scanned the brains of 18 individuals receiving high doses of testosterone as part of female-to-male gender reassignment surgery before and after hormone treatment. After just four weeks of receiving testosterone, participants had lost gray matter (which mainly processes information) in the regions of the brain that are used for language processing. That change amounted to a “real, quantitative difference in brain structure,” said researcher Rupert Lanzenberger of the Medical University of Vienna.
The study, while small, provides tantalizing new evidence of how hormones can influence brain chemistry. As Lanzenberger says, “these findings may suggest that the genuine difference between the brains of women and men is substantially attributable to the effects of circulating sex hormones.”