In a scientific first, researchers claim to have found that differences between men's and women's brains start in the womb.
The conclusion is likely to be controversial, with some experts claiming social influences are more important.
But scientists who did brain scans of 118 foetuses in the second half of pregnancy to analyse the links between gender and the connectivity of a developing brain believe the differences are biological.
Funny how biology keeps showing up as a defining issue. The structural brain differences between men and women are many and well-documented, with new ones being discovered all the time. For example, I recall Oculus Rift having problems working with female gamers because the way their brains process visual information is different from males.