Lots of folks - well-intentioned and otherwise - like to point out the supposed differences between male and female brains. But it's time to throw away the brain gender binary, according to a study published this week in the Proceedings of the National Academy of Sciences. Brains can't really fit into the categories of "male" or "female" - their distinguishing features actually vary across a spectrum.
It's exciting news for anyone who studies the brain - or gender. And it's a step towards validating the experiences of those who live outside the gender binary.
"Whereas a categorical difference in the genitals has always been acknowledged, the question of how far these categories extend into human biology is still not resolved," the authors write in the study.
Structural differences in the brain - and differences in behaviour - are often taken as evidence that brains can be distinctly male or female. For this to be true, the authors write, the differences would have to be consistent: those who were biologically male would have to almost always have "male" features and not female ones in their brain.
But in analysing the MRI scans of about 1400 individuals, researchers, led by University of Tel-Aviv's Daphna Joel, found that mash-ups were more common. They believe their study is the first to look for brain differences between genders by using the brain as a whole, instead of pointing out individual structures and features (like size, amount of grey versus white matter, and so on) in isolation.