In the whole 'nature vs. nurture' debate, one need s to remember that homosexual inclinations are not exclusive to mankind. Homosexual behavior is present in every species...This fact alone kind of puts to rest the idea that people are taught to be 'gay', or that they make a 'choice' based on social factors. The behavior (for lack of a better phrase) is as natural (albeit by no means the majority) as heterosexuality. I don't know if there is or is not scientific evidence to ultimately debunk the myth of it being a choce, but simple observation of non-human societies on this planet clearly establishes that it is not a human phenomenon.