Genetics and Sexuality

Yes I think there definitely could be a genetic link. One of my uncles is also gay. It always seems to be the aunts and uncles, lol.

 

One of my maternal aunts is a lesbian, the other is bi. I'm not sure if my mother was completely hetero (she died when I was younger), but that's it for the LGBTers as far as I know...

I am VERY similar to my mother, and to a slightly lesser extent, her siblings in most other ways, including looks, food preferences, interests, hobbies and medical issues.

 

I have an uncle who is transgender & a female cousin who is bi.

I agree with Lance, it could be in genetics. But who knows for sure.

 

There's probably some genetic component to it. But definitely not a single gene that determines sexuality like an on/off switch. More like a whole series of genes that, in some combinations, cause you to develop non-straight.

Personally, I'm the only one in my family, though (unless some family members are very good at hiding indeed). So either I'm just the first to have a combination that turned me gay.

Alternatively, I might be a mutant. Being gay is a pretty fabulous mutant power to have, I say

 

My uncle was gay too! Aunts and uncles really does seem to be a bit of a trend, hehe.

 

No one in my family was bisexual or gay, none that I know of anyway. Most of my relatives have kids, I know this means nothing when it comes to sexuality but hey.. It's what I'm going on lol.

 

There is definitely a genetic aspect to sexuality. This can easily be proved by linking it to obviously genetic traits - for example, one study found that 23% of gay males have counterclockwise hair whorls (a known genetic trait), compared to 8% of straight males. That's almost three times as great.

 

That I know of, everyone in my family is straight. My family is huge though, and I'm close to a lot of my extended family too (right out to second and third cousins), so I'm talking about a couple of hundred people on each side. It's a bit of a depressing thing to think about to be honest. If there is a gene that makes people gay, maybe it's pretty much non-existent in this town.

 

I wouldn't be surprised if it were more heavily influenced by epigenetic factors rather than strict genetics.

Also, the prevalence of uncles and aunts is to be expected, as parents are less likely to be gay for obvious reasons.

 

I agree that it's more likely to be epigenetic than hard-coded genetic. If you figure that everyone carries genes for an attraction to men and women (so that they can pass them on to male and female offspring), and that hormones and environment are supposed to activate those at the right time, I think perhaps something unrelated causes the wrong set to turn on, or both sets, or neither.

I can distinctly remember being asexual as a kid. It was very much like a switch flipped in my head when I turned 12. Had no sexual thoughts at all, thought sex was gross, never had crushes, didn't understand the appeal, and then BAM!

I actually work in genetics, and I am pretty confident that everyone under the age of 40 will have their genome sequenced before the end of their lives. A widespread study of the actual genes in queer populations should help solve a lot of riddles.

 

I have a gay uncle as well, and a cousin who might not be straight, but that's just speculation on my part.

 

Well, it makes sense that aunts and uncles would be the trend, since if they're de-closeted it's less likely that they have genetic children.

But, like all parts of human development, sexuality is a very complex combination of genetics and psychology. Everything in your personality isn't 100% set at birth, but you are much more likely to come out with certain traits than others. Likewise, incredibly significant events at very early stages of development can change you in significant ways.

However, the fact that it isn't 100% genetic doesn't make it a choice. By that logic, you could say people 'choose' to feel everything, good and bad. In some ways, sexuality IS a 'mental disease.' The only problem with calling it such is that 'disease' means 'having negative effects on the person,' which no form of sexual orientation does. Just like actual, harmful diseases, you probably could change sexual orientation with the right application of drugs to the parts of your brain that control sexual attraction and make ANYONE gay, straight, or bisexual. However, there is no reason you should because there are no harmful ramifications of being gay, straight, or bisexual that require any more 'curing' than getting people to be less bigoted. (Although, in the grand scheme of things it would probably cost less to research a drug to change sexuality than it has with all the campaigning costs of trying to get people to not be assholes about everything.)

 

My current thought process is that it's more likely epigenetic as was said before.

 

There is evidence that serotonin re-uptake activators could affect sexual orientation. This is a very rare class of drugs that isn't prescribed, mostly because low serotonin could lead to depression. We have observed in several studies that the opposite drugs, SSRIs, which are commonly prescribed for depression and anxiety, can reduce fetishism in people that have strong fetishes. Mice born with a gene that gives them low serotonin turn out to be completely bisexual. Feeding them extra serotonin as adults causes them to behave heterosexually again.

Humans might be a bit different though. We're more complicated upstairs, and just because something chemically changes doesn't mean that pathways we haven't memorized and conditioned ourselves into don't stop working.

I would not be surprised though if very, very low serotonin levels in humans could strip off an inhibitor on genes that control sexual attraction to one gender.

 

I'm so far the only LGBTQ person I know in my family, but there may be some who did not or have not come out due to the still-prevalent notion in Chinese society that it's the duty of a man to marry a woman and carry on the family name. There are millions of hetero married couples in China in which the husbands are gay, and married due to their perceived familial obligations and filial piety.

 

Do you have the full reference for this paper please? I'd be interested in reading it.

 

The most popularly accepted belief in the field of evolutionary psychology is that homosexual is determined by both genetic and prenatal environmental factors (most likely exposure to hormone levels). There are two widely accepted scientific theories as to why homosexual (or bisexuality) could have evolved as a beneficial trait. Note that both of these theories are based on male sexuality (because science is sexist).

Theory 1. The first theory is that there is a gene that makes people more attracted to men than average. When a male obtains this gene they become gay (or bi) and on average these individuals should produce significantly less offspring. However, the women with this gene produce more offspring than usual because of their over active sex drive. Thus, the gene is spread even though the male individuals with it are not producing offspring.

Evidence for theory 1: There is a strong postive correlation between the number of homosexual males on the mother's side of a male homosexual individual, but a correlation of 0 between the same thing on the individuals father's side. In other words, there is strong evidence that homosexual males obtain the "gay gene" from their mother and not their father.

Theory 2: Bisexuality increases an individual of producing offspring, and homosexuality is simply a biproduct of two much of the "bisexuality trait." The theory is, that a gene evolved that made people bisexual, and that provided an evolutionary advantage. Theoretically its because either they could relate to women more or more likely because other males would not view them as a mating threat. Imagine this scenario:

Wife: "I'm gonna go pick berries with Og" (Imagine a hunter gatherer society, as our brain's haven't really changed since)
Husband: Oh, that's the one that likes to have sex with men, he won't do anything "Okay, have fun."

Then according to this theory, basically Og is secretely a bisexual caveman who makes sweet love to the woman, and then the sucker of a husband ends up dedicating all of his resources, time, and energy on raising Og's children and ultimately increasing his chances of creating viable offspring and passing along the bisexual gene.

Of course this theory does not deny the existance of exclusive homosexuality, it merely explains it by being a biproduct of a bisexual getting too much of some hormone or something and then getting an overdose of the effect.

Evidence for theory 2: There are significantly higher number of people reporting at least some sexual experience with both the same and opposite gender as opposed to merely the same gender.


tl;dr: Yeah, genetics play a factor.

 

While a lot do have crushes I doubt many think in sexual terms until puberty hits. I know I sure didn't and I'm a bisexual guy who had a crush on a girl in my class in kindergarten. Even then guys who like girls have the whole "cooties" thing. I think, I may be wrong, girls are more in tune with that early on whereas it hits guys later partly because of the sexual part.