Our society also insists on real biological links with social phenomena - parenthood is only "real" if the child bears the genes of both parents, and people will go to impressive lengths to get such a "real" child. Maybe you needed more than transvestism for similar reason, because you can't feel as a woman without the physical attributes which are so important in our society (And then, probably you really needed those hormones).

I'm also thinking of the cases of the basketball players getting late, large growth spurts, in how encultured behavior could have very large physical effects. The intersection of the cultural and the physical is much larger than we often estimate ; and much of it remains unconscious. Maybe our "nurture", our competition friendly society, causes higher testosterone levels that make transgenderism hard, whereas Pacific cultures wouldn't cause such level of testosterone, particularly for someone raised as a girl...

Sometimes the localism of much of Neuroscience and Hormonal research (like much of experimental behavioral research) is depressing : it would be interesting if these sciences studied more that US college students and a few others...

Un roi sans divertissement est un homme plein de misères