Gay Science 101

I've always been under the impression that genetic studies are very circumstantial right now. Although a lot of studies show that there is some sort of biological influence over our sexuality, I don't think anyone can point to one specific thing and state that it's the cause. Personally, I don't think that a so-called "gay gene" exists and the twin studies agree with that. If it was determined solely by genetics then identical twins would share the same sexuality almost 100% of the time. I think that if there is any genetic basis at all it is because an already existing gene has been altered in some form and is then expressing a same-sex attraction in conjunction with a hormonal balance or something like that.

As far as whether homosexuality is "normal" in human beings is a tricky question, because of the way you asked it. Unless we are speaking statistically, there is no such thing as "normal" that doesn't have a pejorative meaning. A better way to ask the question would be "Is homosexuality common in mankind?" The answer to that question is no, but it does and always has existed and always will. It is natural, but not "normal," and that's perfectly alright. Blonde hair and blue eyes are abnormal in the same way, statistically speaking, but I really don't think anyone would say that those things are bad.

 

Oh, my apologies then for the misunderstanding. ^_^

Yes, homosexuality is perfectly natural. If it exists in nature it is natural by definition. Anyone can go see gay penguins at the Bremerhaven Zoo on any given day of the week. They're so cute.

Gay penguin dads in German zoo hatch their first chick - latimes.com

A lot of animals, mostly mammals, display homosexual behavior and have gay sex and humans are mammals so...

 

Sexuality and Gender in regards to science is a somewhat new concept, and as with all subjects of scientific interrogation, it's all about time, money and sample size.

Right now, there's LOTS of research (in Australia at least) being done in regards to sexuality and science. The problem is, the kind of experiments needed for this level of research are long, expensive, subject to SOOO many external variables (many of which I'm sure we don't even know of) and very difficult to do in large numbers.

Also, there are a lot of different paths being taken from scientists in regards to sexuality. The most common I would assume is a genetic approach, but endocrinological studies are also being favoured. Most difficult of all, are those trying to imitate 'nurture/conditioning' type hypothesis.

Personally, I'm confident that science will discover an answer as to the cause of sexuality variation, but I believe it will be significantly in the future and the answer will be a combination of things, not just a single cause.

 

Since homosexuality happens in animals naturally, I'd say it's normal.

As for the cause of homosexuality, there are a few theories, but none of them perfect.

1. Homosexuality is caused by an overload of feminizing genes, that, when activated in moderate, makes a male more caring and more attractive to females for being more likely to help raise children, but when activated in excess, causes attraction to other males.

This doesn't really go well with the popular notion of equality of personality traits between gay men and straight man, that gays and straights are fundamentally the same aside from their sexuality.

2. Homosexuality is caused by a gene that, when present in females, causes them to be more likely to have off-springs (either in better birth rate or tendencies of promiscuity), but when present in males, causes homosexuality. There is in fact evidence showing that a homosexual man is more likely to have homosexual relatives on his mother's side.

The study researching this theory also shows that it only explains a small proportion of all homosexuality cases and is more likely to be a correlation than the main explanation.

3. Homosexuality is caused by the mother's immune system attacking the Y-chromosome during pregnancy, causing demasculinization in the unborn male. There is evidence showing that, the more older brother one has, the more likely he is gay. This is believed to stem from the mother building up her immune system towards the Y-chromosome from each pregnancy with a male.

Again, this study only shows a small proportion of all gay males, and does not give a good explanation for gay first-borns.

I simply very briefly summarized this 3-page article from psychology called Finding the Switch. I encourage you to read it as I found it very informative when I first came upon it.

And sadly there doesn't seem to be much studies about bisexuality and female homosexuality going around.

 

I think Wikipedia has a pretty comprehensive overview of this topic. While I don't agree with everything, I think it shows a wide variety of viewpoints and theories.

I mostly know about the biology of gay men, so I am sorry if this is rather one sided. One of my favorite theories of the evolutionary biology of homosexuality is the "gay uncle" theory. The idea is that as a woman has more children she is more likely to have a gay son. When her children have grandchildren, they may have a gay uncle who will not have children of his own, and will instead take care of his nieces and nephews thus improving their survival chance. One of the studies that supports this looked at Samoan gay men. Samoa is one of the few societies where gay men are fully accepted and they in fact do play the role of gay uncle. The study investigated the neurological response of the men when faced with aiding their family versus others. While the control group had a preference for their family they were also willing to help others. Among gay men however, there was a strong preference for blood relatives and very little preference for aiding others. The authors inferred that this showed that their brains were evolutionary wired to be more protective of their blood relatives supporting their evolutionary role int the groups survival. While this is not conclusive, I think it illustrates some of the interesting work that is being done in the field.

If this theory is true, it presents some interested problems for the role of gay men in our society. Families today are much smaller and more spread out than they once were and furthermore, they tend to be focused primarily on the nuclear family rather than including the extended family. Thus, being the fun bachelor uncle (read: gay) is no longer that feasible. I wonder if as many gay people would try to start their own families if they were able to fit in better with their extended families and be close enough to their nieces and nephews to consider them their own kids. It is something to ponder.

There is also a guy named Nicholas Rule who is currently investigating "gaydar." One of his studies showed that people able to identify people as gay or straight with a better than chance accuracy after seeing their faces for less than a second. Here is the link to the paper is you are interested.

 

The problem that we have in answering this particular question is that 1) it assumes that there's a single "cause" of homosexuality and 2) underlying a lot of this research is a bias that there's an abnormality to be found that explains a "disorder" called "homosexuality".

Is it really surprising that everyone is capable of sexual satisfaction with both genders? Is it surprising that some people have a preference for one gender more than the other?

There's certainly a genetic predisposition for sexual orientation. But in societies where bisexuality is accepted as a part of a "norm", more men are sexually active with men. In societies where premarital sex is forbidden, there's a hidden subculture of men who are sexually active with other men until they marry women.

So, the question is whether some of this is artifice that doesn't need to exist. Perhaps everyone is capable of bisexuality but societal convention forces everyone to follow the attraction that is the strongest- whether it be to the opposite sex or the same sex.