Sunday, 3 August 2008

Evolution and homosexuality (1)

The standard argument with a homophobe kicks off with them saying "Homosexuality is not natural!"

To which a sensible chap responds, "No; it's perfectly natural, what you means is that it's not normal, i.e. only a small minority of people are gay, the same as only minorities are left-handed, ginger, insomniacs or particularly good at football, maths, music etc. Being gay is no less natural than any of these things."

Scientists have batted this question back and forth for ages, whether homosexuality is down to nature or nurture; I strongly suspect the former*, given that:

a) Most parents are - by definition - heterosexual, so why on earth would they bring up their kids to the opposite?

b) Most civilised Western countries are pretty tolerant of homosexuals (some more than others, obviously), but even in hideously homophobic countries, e.g. Islamic countries, there are just as many gays. So it's not a lifestyle choice; not one that any straight person would choose anyway; and if you're not straight, then the chances are, you are gay (by definition).

So what evolutionary mechanisms are there to ensure the survival of 'the gay gene'*?

More anon.

* This assumes that there is a 'gay gene', quite possibly there isn't - it's even cleverer than that, which I'll cover in part 4.

8 comments:

Anonymous said...

Assuming a genetic cause, which there is evidence for, it can still be perfectly natural. However, it needn't be pathological, as say haemophilia is, it could be strategic. Consider the sexual behaviour of gays may not be misdirected through error but rather intentionally redirected towards the non-reproductive. Edward O. Wilson advanced that if one forwent one's own reproduction and instead invested effort in the rearing of family members then their is sufficient relatedness between those kin to ensure the propagation of the shared genes (gay and otherwise). Indeed, in harsh circumstances, it might be highly adaptive. It is common in many animal species for reproductively-capable adults to raise others offspring instead of their own for precisely these reasons.

Even then, you can "become gay" in a number of ways besides the genetic path.

1) Early sexual experiences can impress particular desires upon you. This is how many fetishes emerge.

2) You can engage in homosexual acts through the absence of alternatives or in because of particular circumstances. This is often called situational sexuality and accounts for the high incidence of homosexuality in prisons amongst otherwise heterosexual men. In a larger scale we see that homosexual behaviour can be culturally encouraged, e.g. Ancient Sparta and Thebes.

3) Exposure to particular hormones can cause homosexual behaviour. These hormones do not have to be present in adulthood, but can have already had their action in the womb. Studies of rats have shown that the sex ratio of the litter influences the sexual behaviour of the rats born from it. Thus male rats that shared a womb with females showed more feminized sexual behaviour than male rats that shared the womb with males.

Anonymous said...

1, there is no such thing a a gay gene, there could be a combination of genes that make it more likely ect, we shall see in time.

2, the most likely answer as to why some folks are gay and why it appears in nature with no visible support is properly down to how your brain formed in your mothers womb .

Gay males have a more female type brain map, and you are more liable to see this if you are younger child, esp after the 3rd child.

So it biological, thus nature did it. And you will continue to see it in nature even without a gay gene.

another interesting point is IQ, gay gays tend to be smart, females on average are smarter than blokes, but blokes tend to have the capacity for higher intelligence and the price they pay seems to be more mental illness and lower IQs. Gay guys have female brains so you are less likely to meet a stupid one.

I suggest you give Mr Pinker a read, esp the Blank slate, it seems we are born with the capacity for language and morality, and its all down to configuration of the brain.

Mark Wadsworth said...

PT, PB, excellent points indeed, I will cover these in a later episode ...

Anonymous said...

On rereading my comment and wincing through the typos, I should note that W D Hamilton that really put forward the theory of kin selection, it was Wilson that suggested homosexuality may be a variant of it. The problem with any genetic explanation is that in seeking to explain the behaviour, one can run the danger of trying to excuse it. Whether it is chosen or not does not affect whether it is right or not. As Hume would say, you cannot prove an ought from an is.

This is problematic because of what I mentioned earlier. If people can become homosexual or behave so through different means, we run the danger of validating the behaviour through some paths and not through others when we adopt a "oh, it's natural" approach.

Frankly, I think being a gay male sounds to be an absolute blast, even despite the rampant homophobia (at least in these Northern parts).

Mark Wadsworth said...

PT, you've lost me with your first two para's, but as to "Frankly, I think being a gay male sounds to be an absolute blast ..." maybe that's the reason for homophobia; they don't have nagging wives, screaming kids, they get the coolest careers etc.

Vindico said...

"So what evolutionary mechanisms are there to ensure the survival of 'the gay gene'*?"

Musicals?

Anonymous said...

Last I read of a pop-science summary, being gay was easily explained. All conceptions begin female. For eventual boys, the brain and the body turn male early in pregnancy, but at different times.

A homosexual man is simply a physical male who's gestation was interrupted at the time when the brain was meant to be turning male.

Seems to explain every single observable difference between gays and straights, its persistence despite being an evolutionary unstable strategy, and why it's totally unrelated to lesbianism.

Nick

Anonymous said...

Okay, Mark. My point is that we as a society tend to excuse the innate. For example, being a particular skin colour is fine (at least nowadays) because we have no choice on our colour. Thus the debate about the genetic origins of homosexuality has important bearings on the acceptability of it: do gays have a choice?

I then made the point that it doesn't matter whether it is natural or automatic, with regard to whether it is right or not. Just because something is a certain way, doesn't mean it should be a certain way. Just because you are gay, doesn't mean it's okay to be gay. That it is natural is not a justification in itself.

The problem with seeking to justify homosexuality from a genetic perspective is that it can cast aspersions on those that choose to be gay, rather than are born it.