Back in the dark ages when my mom had me, it wasn't widely known how harmful smoking was to a developing fetus...in fact, in the fifties-when she grew up, ciggies were promoted as a cure for morning sickness!
This is probably why I've had health problems as severe as I have had, and why I was born prematurely, at just over five pounds, then dropped weight after birth to five pounds even. And had to be kept in an incubator for a month. I was only half-baked, I guess...
Recently I happened to *ahem* be looking up natural aromatase inhibitors...and you talking about this suddenly made me think of a connection...nicotine is an aromatase inhibitor.
Aromatase inhibitors prevent estrogen formation...and as I understand it (I may well be quite incorrect)...
...Since you just have these generic sex hormone precursors floating around, that then get processed in the liver, well, if you add an aromatase inhibitor, what you end up with is more testosterone instead...
So maybe my mom's smoking while she was preggers had something to do with it?

That would be really weird.
Mis/ter Alex, I suspect it's just one of those weird things to do with brain structure that we just haven't figured out yet. An accident that occurs between development and genetic potential. That's how most things work with humans, even with things that have strong heritability-like schizophrenia.