nail
on
head!
that's not entirely true.
Maybe youre familiar with Indian Hijras:
http://en.wikipedia.org/wiki/Hijra_(South_Asia)
Native american Berdaches/two spirits
http://en.wikipedia.org/wiki/Two-Spirit
Thai Kathoeys
http://en.wikipedia.org/wiki/Kathoey
and Eununchs in countless cultures in history
http://en.wikipedia.org/wiki/Eunuch
As far as the theory about 'reptilian' brains, I hope you're just stating what people generally believe and not that this is your opinion! The idea that men with feminine gender characteristics (not sex) are somehow less able to 'propagate' is just purely misogynistic! That kind of thinking dictates that survival of the species relies on masculine 'strength' and ability to provide. This is just silly, especially in 2011. And human sexes in general aren't even very different compared to many animals where the differences and genetic responsibilities of those animals are more clearly defined.