Brains and Sexual Orientation
http://aebrain.blogspot.com/2009/06/brains-and-sexual-orientation.html (http://aebrain.blogspot.com/2009/06/brains-and-sexual-orientation.html)
Zoe Brain
6/5/09
There's one group who provide positive proof that a cross-gendered sexual orientation sometimes has a neurological cause. That is, kids whose behaviour from an early age is typically cross-gendered.
I've been unable to find good data about sexual orientation in later life for the transsexual kids who exhibit cross-gendered behaviour early, but suspect they all grow up to be straight, the classic "primary transsexual" described by Benjamin, just as the non-TS kids who exhibit similar behaviour grow up to be gay. And that's the majority of them. Only 1 in 3 of such children are transsexual. Moreover, most women with CAH syndrome, while tomboyish in early childhood, appear to be mostly straight in later life. So our understanding here is limited.