Yeah, another study not to long ago showed that men and women (with comparable training) often arrived at the same answers or conclusions or performed similarly, but different areas of the brain lit up when they were processing. The point was that the brain is highly flexible and elastic and is capable of doing a great many things no matter who the person is, but different parts of it can be "trained" to perform the same activity or to compensate for another part.

Another interesting study is where people who have had some kind of brain damage or even other kind of impairment and the brain creates new pathways to compensate for that loss or alteration.

So, yeah, when you don't use a part of the brain, that part gets diminished as unnecessary, but it doesn't automatically mean that a person is "naturally" any particular thing.

One of our greatest evolutionary achievements is the malleability of our brains, the ability to adapt and alter ourselves to suit the circumstances. If survival requires girls to be "girlie", then the girls who are best at developing those parts of the brain will pass on that ability, but when girls are encouraged to be something other than "girlie", for however you want to define it, we're totally capable of that too (and guys).