The right to mis-define oneself

[bennyboy]

Transgendered people can be shown to have the same brains as the gender that they claim to be. It's been known for a long time but now we don't have to dissect the brains of trans people, we can scan them while they're still alive, even before they start taking hormones.

So this means that someone born with a vagina, but whose brain does not have this "female" structure, isn't really a woman? It seems to me that by defining gender as something different than sex, you are invalidating the identity of at least some women.