the dominant scientific opinion is that homosexuality is HARD WIRED -- in other words, you are "born that way." there is evidence that there may be subtle differences within the brain structure of homosexuals and heterosexuals, and there is also support for the notion that, during a pregnancy, hormones that "flood" the fetus -- the "hormone dump" that determines whether a fetus will remain female (as all feti start out female) or become male -- affect the fetus differently. in other words, a fetus that gets a "dump" of testosterone becomes male; if there are differences in the levels of hormones dumped, the result is a hard-wired sexual orientation of homosexuality.
there is even more solid evidence that transgendered people have distinct brain differences -- a man who is born into a male body but feels all of his life that he is a woman? there's a reason for that. such a person DOES have the BRAIN of a woman -- there are structural differences in the mail and female brain. transsexuals truly have the brain structure of the opposite of their physical sex!
and yes, of homosexuals who can remember back that far, many many many say that they have ALWAYS had their sexual orientation -- going back to the earliest memories at age 2, 3, 4, etc., they recall having attractions for MOTSS (members of the same sex).
the notion that TRUE homosexuals are "taught" to be gay has been debunked. a TRUE homosexual is born that way, to put it succinctly. there are, however, people who engage in sexual acts that run contrary to their TRUE orientation -- for instance, a man who is raped in prison by another man has not been "converted." if he was a heterosexual before he was aped, he will be heterosexual afterwards.
homosexuality is an ORIENTATION. it is not a LIFESTYLE or a BEHAVIOR -- just as heterosexuality is an ORIENTATION, not a lifestyle or behavior.
a heterosexual woman can display homosexual behavior by having sex with a woman; that does not change her orientation. she could have sex with a woman for many reasons other than physical attraction.
in looking at the term "lifestyle," one should ask what is the heterosexual "lifestyle." hetero men and women have many, many, many different ways of being heterosexual -- so do gays, lesbians and bisexuals. there are heteros who are family-oriented, who are sex-crazed playboys/girls, who have little interest in sex at all -- ad infinitum, the list goes on and on.
it doesn't make much sense to say that a gay man had a "domineering mother" or whatever and that's what made him gay -- there are many, many, many gay men who do not fit the limp-wristed homosexual stereotype. they are not, however, usually SEEN as being gay, though, because the don't APPEAR to be gay. my brother is a case in point. he looks and acts just like every other semi-truck driver on the road out there in his jeans and flannel shirts, listening to his country music. he is "invisible" though because he doesn't fit the nancy boy stereotype.
also, it is unlikely that homosexuals -- the vast majority by far of whom are raised by heterosexual parents -- "learn" to be gay. the "it's mom's fault" or "it's dad's fault" factor additionally makes no sense when one considers homosexuals who have brothers or sisters who were raised by the same parents and did NOT "learn" to be gay.
just some food for thought from someone who has done one hell of a lot of reading and research in trying to understand his own brother.