((I couldn’t find this anywhere else on the threads, but if I missed it, please post the link to the already existing discussion. Thanks!))
I have found old information (from the 90s!), and I have found bias information, neither of which I trust. Who can tell me the sound scientific evidence: has the “gay gene” been proven to exist or not? Citations appreciated!
((Please do not turn this into a debate of ethics/morals/politics/religion/opinions/etc.))
The best bet is on a mix which varies by person.
Nothing’s been proven to exist yet. The person who was doing most of the research on that was Dean Hamer, and he’s moved on to other things. Basically, in 1993, Hamer (he’s a researcher at the National Institute of Health) published a study arguing that a gene on the X chromosome, gene Xq28, seemed to be linked to homosexuality in men A few other studies seemed to confirm that. However, in 1999, there was another study done, this one by geneticists at the University of Western Ontario, that contradicted Hamer’s 1993 study, didn’t find a correlation, and suggested that Hamer’s study was flawed, and other studies have also not found a link.
There was another study in 2005, that didn’t find a link with gene Xq28, but seemed to find links between homosexuality and other genes. Here’s a copy of the 2005 study, if you’re curious:
http://mypage.iu.edu/~bmustans/Mustanski_etal_2005.pdf
But like I said earlier, the “gay gene” has not yet been proven to exist.
I thought the current paradigm was not so much genetic, but that most scientists were focusing on variations the in utero-hormonal environment and its effect on the developing brain as being the most powerful determinant in influencing sexual preference.
I saw an interesting argument by a geneticist who said that he had reason to believe that the “gay gene” is actually gene that promotes attraction to men (instead of attraction to the same-sex). This gene is typically found in women, but some men have it too. Likewise, most men have an attraction to women gene, but some women have it too. Of course, I can’t remember where I saw this now, but I remember thinking it was kind of a revelation to me.
This geneticist’s argument doesn’t make much sense. Unless the gene is on the Y chromosome, there isn’t any reason that a gene would be “typically found in” women or men. (Yeah, women have two X chromosomes, but men have one and only one gene of the pair is expressed at a time).
You could have a gene that’s found in men and women, but is expressed more by one than by the other, as controlled by some hormonal trigger, though. The gene(s) for facial hair, for instance, is found in almost everyone, but it won’t do much without testosterone to trigger it.
In addition to studies of specific genes, I’m reasonably certain I’ve heard of twin studies, that show a greater correlation of sexuality between identical twins than between fraternal twins, which would suggest at least some genetic influence, but also a greater correlation between fraternal twins and non-twin siblings, which suggests at least some inter-uterine influence.
This is just one example so of course it doesn’t prove anything, but I found it interesting anyway. One of my friends knows a family that has three sons, two of which are identical twins, and all three brothers are gay.
So the prevailing theories are either genetic or inter-uterine, not environmental after birth?
I realize that an adult homosexual cannot really be “converted”, however anecdotal evidence shows me that a stressful life through the toddler years seems to correlate as well.
Note that by stressful" here, I mean both physical, as in malnutrition, and mental, as in abuse.
I’m sure this has been studied, I’m just asking for clarification’s sake.
edit: “shows me” is not really the correct terminology here… maybe "lends to the hypothesis " is better
If there were a true “gay gene”, wouldn’t that be one of the most likely genes to be weeded out through a lack of successfully reproducing itself? Even if those expressing the gene “forced” themselves to reproduce sometimes, over thousands of generations how could it still be so prevalent?
Nevermind, ignore my last post too
It’s not possible, even conceivably, that there is a gay gene. We don’t know for sure what causes homosexuality, just as we don’t know for sure what causes heterosexuality. Even in animals sexuality is complicated, and even in the simplest of animals sexual orientation is affected by more than one gene, so there can’t be said to be a single ‘gay gene’ or even a single ‘straight gene’ or ‘gay or straight gene’. In higher animals in addition to the genetic and developmental factors there are social ones. In humans you also have cultural and memetic factors in addition to the other stuff. Current science says it’s probably a mix of all these various factors, with specific individuals being affected either by all of them or by one or a few dominant factors.
If there were a gene which caused an increased likelihood of homosexuality, but had no other effect whatsoever, then yes, that gene would probably get selected out of the gene pool relatively quickly (at least, relatively quickly by evolutionary standards). But a gene can have more than one effect, especially for things as complicated as behavior patterns. So it’s quite plausible that there exists a gene or genes which increases the prevalence of homosexuality, but which also has other effects conducive to reproduction, and therefore is maintained at some sort of equilibrium in the gene pool to give the highest possible reproductive benefit.
Also, the whole point of evolution is in deviation from what worked in the last generation. You try random stuff in a big shotgun spray and see what hits the mark. Evolution doesn’t follow logic. There isn’t a wise, all-seeing Mother Nature guiding things. It just tries any stupid idea. “Hm, maybe this one will do better with no eyeballs? Let’s try it!” It might not make sense, but that doesn’t mean that Mother Nature isn’t perfectly happy to try it.
It might require more genetic data to be mixed up to cause an eyeless human than a gay human though. It really just depends on how stuff is encoded and how it’s interpreted when the body is being built. It may take a greater effort to breed the decently high probability of homosexuality out than its worth.
The first example that comes to my mind is sickle-cell anemia.
If you’ve one copy of the gene, you have protection against malaria (that’s a plus!) If you have two copies of the gene you have sickle-cell anemia (thats a BIG minus)
Depends on your definition of “homosexual.”
Evidence abounds of variability in sexuality. Just as some people are “completely heterosexual,” and others are “completely homosexual,” there are countless variations in between.
Now, I don’t have cites, but I believe that there is greater variability for women than for men. Anecodotally, that seems about right. The “lesbian in college, married to a man after graduation” effect is real for some women. Men, however, don’t seem to have as much variability. And certainly don’t have the same cultural acceptance (at least in Western cultures).
A woman kissing another woman is “hot,” but doesn’t mean she’s a lesbian.
But a guy kissing another guy means he’s gay, for now and eternity, and will never, ever be trusted with a woman again-- if he’s ever involved with another woman, he’s obviously hiding in a closet, and hypocritically denying his true sexuality.
Right. Uh-huh. I’m sure that’s how that works.
Personally, I think there are probably far more bisexual people than commonly understood. How that breaks out by gender, age, etc., is anybody’s guess. Culture probably has a lot to do with keeping such things in there “lanes,” as it were.
I can think of two possible advantages to the “gay gene”, assuming it or they exist. The first is that it might be advantageous to generation X if generation X-1 had a few adults in it that didn’t reproduce. There would be a larger adult/child ratio, with more adults to attend to the children and to gather or create resources. Adults are a child’s main resource.
The second is that being gay does not preclude reproducing, but it might slow down the rate of reproduction, allowing more than a year between pregnancies. Most modern people forget how recent birth control is. A married pair that has five children is more likely to see them survive to adulthood than one that has fifteen or more. And the female half of the pair is less likely to die in childbirth or have her health ruined by overbearing.
I know of a LOT of gay men that have children. I think it was even more prevelent in the past when to conform gay men got married and had kids. So the gene would be passed on easily.
I also see in young kids (both male and female) they are just more open to trying it. When I was young there was no way in “heck” any straight male would ever even THINK about gay sex. But now the attitude is becoming like “Well I’m horny and no one else is around. So what.”
Even if they don’t like it, younger people seem willing to try it, which seems to me it’s becoming more and more likely to stop being an all or nothing thing and become a range of sexuality.
I recall a quote from “Rolling Stone,” magazine, where they asked Daryl Hall if he was gay, and he said that he has had sex with men in his younger days but he’s with a woman and he likes women better. (He also said that he’s never had sex with John Oates and as far as he knows Oates is straight) 
So you can see the difficulty of classifying people as either or
I know of a LOT of gay men that have children. I think it was even more prevelent in the past when to conform gay men got married and had kids. So the gene would be passed on easily.
I also see in young kids (both male and female) they are just more open to trying it. When I was young there was no way in “heck” any straight male would ever even THINK about gay sex. But now the attitude is becoming like “Well I’m horny and no one else is around. So what.”
Even if they don’t like it, younger people seem willing to try it, which seems to me it’s becoming more and more likely to stop being an all or nothing thing and become a range of sexuality.
I recall a quote from “Rolling Stone,” magazine, where they asked Daryl Hall if he was gay, and he said that he has had sex with men in his younger days but he’s with a woman and he likes women better. (He also said that he’s never had sex with John Oates and as far as he knows Oates is straight)
We know for a fact that there is no such thing as a gene that always makes someone gay, because identical twins aren’t always either both gay or both straight. It is true that if one twin is gay the other is much more likely to be gay, and if one is straight the other is much more likely to be straight. But there are plenty of identical twins where one is gay and the other is straight.
If homosexuality were caused by a “gay gene” then this would be impossible, or rather very very rare since it’s possible for mutations to occur after the zygote splits.