I'm not a scientist, nor do I play one on television.
But based on what I've seen during my years on this planet, I'd say that there are probably many ways in which homosexuals are "created;" all of which stem from a combination of the chemistry they were born with and the environment in which they were raised. I have direct knowledge of at least one instance in which a South American child was adopted by an American couple and raised in an extremely "hetero" environment---Italian-American, in fact---and yet you could tell from just about the time this child could talk that he was going to be gay. When most boys this child's age would reach for the trucks, bats, construction equipment, etc., he'd be searching out the tutus and tiaras in the dress-up chest. There was literally no way this child was going to grow up anything other than gay.
Yet I'm sure there are plenty of people out there who grew up "confused" about their sexual identity and were pushed down the homo route by another homosexual, or someone who molested them.
I'm an engineer and/or a computer scientist, depending on the title. I'm not a geneticist, neither am I a climatologist but I can study climate data and understand global warming is based on bad science and pushed by agenda driven, power and money hungry people.
In regards to homosexuality, a lot of people on both sides don't understand the issue, mostly because it's quite complicated and also because they're not familiar with some terms and what the terms mean.
When I say biology plays a part, people on both sides of the issue take that to mean something very different from what is meant. To some who think homosexuals are born with their same-sex attraction, they say: "see, even scripter says biology plays a part." To some who think homosexuals are not born with their same-sex attraction, they say: "no it doesn't." It's complicated.
When I or a geneticist says biology plays a part, what is meant are traits and linkages, and neither are even remotely causal to same-sex attraction. I believe this is the most confusing part for most because they don't understand the terms.
Playing with tutus and tiaras means nothing other than it fits some stereotypical model society has fostered on us. The same is true with effeminate men. There are more effeminate heterosexual men than homosexual.
If you're basing any opinion on this child who play with tutus and tiaras, you've bought the sterotype and is something you should seriously reconsider.
I encourage you to read two stories:
Michael Glatze
Charlene Cothran
Both the above ran homosexual magazines before leaving the homosexual life.