I am not that young, but when I was at medical school, we were taught that any research into genetic reasoning for sexual orientation is doomed to failure as the exception clause is too large.

The need to socialise with members of your own gender is in the vast majority of people. The need to care for and be altrustic towards people you find attractive is in the vast majority of people.

The mix and match, moral thought deduction and impulsive action from just those can cover every eventuality with no gene change whatsoever.

Effeminate men and butch women exist in both heterosexual and homosexual personas.

You can't help being gay any more than you can't help liking brussel sprouts. Different people can react to conditioning in different ways though.

You are what you are, or as a colleague from Jamaica tells me, you is what you is.