I don't "believe" anything with regards to the brain Lorelei76. That's my whole point we don't know. Considering how little we know about the brain.
I've observed differences in male/female behaviour, what the causes of those differences are re: nature vs nurture I am completely lost at sea, and have no earthly clue.
I have also observed similarities in men and women also, which leads me to align with Socrates position from over two thousand years ago which is to say any differences between men and women are so slight that there is no logical grounds from barring women from any endeavour a man might choose to do.
Furthmore measures of general intelligence reveal no major differences between men and women, so that leads to the conclusion that there should be no impediments to opportunity for either sex.
Where I am a little cautious in going too far down the rabbit hole of assuming our brains are identical is that I am dyslexic and as such have more than a passing interest in how my brain is structured vs a normal one.
When last I looked into it (and more current research may supersede it), there seemed to be data to suggest differences between male and female dyslexics. Which iirc involves more the connections between regions of the brain rather than the regions themselves.
A case was made at the time that services designed to help dyslexics assumed male as the default, and there may be ways of assisting female dyslexics tailored to them.
It would be a shame to close off avenues of inquiry that could help more women achieve their potential simply over an ideological purity.
Furthermore there are correlations between some psychiatric disorders and sex, like for example ASD which something like four times as likely in boys (although the jury is out on wether girls are are better at hiding the symptoms).
It's possible that the answer doesn't lie in the brain at all, but perhaps the endocrine system. It's possible girls are insulated through the social bonding hormones oxytocin and vasopressin.