Personally, I had always assumed that homosexuality and bisexuality were orientations that 10% of the population were 'just born with'. Whether this be down to events in the womb or even genetics. However, I had no idea quite how divided the scientific community was on the subject: Study by Anthony F. Bogaert - Details. The womb of a woman who has already had several sons will try to turn a following male baby into a female. Scientific verdict: Mostly unsound. This study is yet another claim based upon superficial research that may be purely coincidental to or entirely unrelated to the conclusion that the researchers are proposing. There is a conceptual leap based upon nothing other than an obvious personal wish/bias, from what may be an interesting chance finding based upon a small population sample to a generalization about the etiology of homosexuality. Joseph Berger, M.D. Perhaps it's genetic? Studies have been done into twins, only to find that they don't always have the same sexuality. They did find that when one twin is homosexual, the number of times the other twin is also homosexual occurs more often than the general rates of homosexuality in society. Interestingly, this study also looked at the rest of the family and they found that the rates of homosexuality among the rest of the family, including adopted brothers was 200-300% more frequent than the general rates in society. And so the data leads to the conclusion that something is causing homosexuality to occur more frequently in certain families but that it can not be genetics because the increase even occurs in adopted brothers who do not share any genes at all with the rest of the family. http://www.exodusglobalalliance.org/causesc37.php How about the arguments for nurture? Hormonal imbalance, sexual abuse or lack of bonding with a same-sex parent. Well if homosexuality is a choice, or at least not particularly permanent, this would make a lot of sense: There are many reports from former homosexuals saying that they have "come out" of that lifestyle. One platform used is Love Won Out one-day conferences that are held in cities across the United States. The speakers include educators, counselors, and ex-homosexuals who boldly publicize that people can change. http://www.allaboutworldview.org/causes-of-homosexuality-faq.htm Well after only a bit of light research, I have found countless conflicting viewpoints backed up with unverified scientific evidence.To be honest I'm none the wiser. Any thoughts? What, in your view, causes deviations from baby-making heterosexuality?