Unless they’re only scanning the brains of neonates, how can they possibly rule out the effects of sexist culture and upbringing?
It’s well known that London black cab taxi drivers develop a larger area of their hippocampus after studying “the knowledge” for their licence.
It would hardly be surprising that a female child raised by sexists on a diet of Barbies, pink glitter, frills and “being nice” might have some artificially produced brain differences to her brother, raised on football, toy soldiers and “big boys don’t cry”.