I wanted to address the idea of whether or not homosexuality is a question of ‘nature’ or ‘nurture’. To put it in more modern words, whether or not homosexuality is caused genetic or a choice. Firstly, the question may be meaningless. By that I mean that there is no satisfactory solution to the question as it is stated. Why? Because whether a given behavioral trait is genetic or environmental is, for any practical purpose, unanswerable. We are not products of traits that either are imposed on us by our genes or produced by our environments. Our genes do not, in any meaningful way, operate isolated from our environments. Our environment, although seemingly separate from our genes, is still influenced by them. So to suggest that homosexuality must be either genetic, in its entirety or environmental, in its totality, is to miss something exquisite going on in nature. Nature, once you look beneath the surface, is usually cleverer than we are.
There are a couple of issues enclosed in the question of ‘is homosexuality a choice or not’ and before I go about trying to answer them, I’d like to try to tease out the separate questions. Question #1 goes like this: “What causes homosexuality. Why are some people gay or lesbian”? Question #2 is best phrased like this: “If homosexuality is not a choice, what possible evolutionary reason would keep those genes around”. Question #3 goes like this: “If homosexuality is proven not to be a choice, what does that mean for the gay rights movement”? I’ll answer each one individually.
What causes homosexuality?
I will own, up front, that this is going to be a really cheap answer. No one knows, definitively, why some people end up being gay or lesbian. There is, however, a convergence of evidence that points to it being a, more or less, innate trait. At some level, it would appear that people are born gay or lesbian. This, however, is a very different statement than saying that something is entirely determined by our genes. Although what filters through to the popular media gives the impression that there is a gene ‘for’ any given trait that is not exactly the case. Certainly, no working biologist would suggest that there is a gene ‘for’, to take one example, risk-taking. So, part of the purpose of this article is to introduce you to a different kind of language for talking about our genes. What is more accurate is to say that there are certain genes (genotypes) that express (phenotype) a particular behavior, in interaction with their environment.
Now, before someone should take the last part of the above sentence to mean that I am suggesting that environment means the usual (and hopelessly outdated) tripe of ‘absent father’ or ‘overbearing mother’ or childhood sexual trauma or any other such pseudo-psychological babble, that is not what I am talking about. By environment what I mean is the complete set of historical experiences that any given individual passes through from the moment they are conceived. Make absolutely no mistake, the womb is part of our environment and is as much part of our history as any house we ever live in. So, for example, if your mother was malnourished during her pregnancy with you, you may (counter-intuitively) have more of a tendency to put on weight.
So, returning for a moment, to the question of gene-environment interaction I’d like to talk a moment about what genes do and do not do. It is, generally, thought that genes code for particular traits. Therefore we’ll say that one has a gene ‘for’ brown eyes or that one has a gene ‘for’ such-and-such malady. In most circumstances, it is convenient but not accurate to talk about genes in this way. Our genes code for proteins. Proteins are little molecular machinery, of various chemical natures, that go about the business of building bones, tissue, cells, brains, etc. If you have, for instance, brown skin your body produces significant quantities of a substance called melanin. Your genes code for proteins that are in charge of melanin production and you will have, on average, darker skin than someone who has genes that do not code for as much of that substance. If you then live in a place that does not get as much direct sunlight then your skin color will be, on average, lighter than someone with similar genes who lived in a place with high direct sunlight. This might sound like I’m stating the painfully obvious but note the language. Specifically, note the use of ‘on average’. In biology, it is useful to think of things happening on a gradient and each individual lies somewhere along that continuum. So, is there a gene for brown skin? Well, yes and no. There’s a gene that produces greater or lesser amounts of melanin. Everyone, who is not an albino, produces some amount of melanin. It would be slightly more accurate to say that there is a gene ‘for’ albinism, but most accurate would be to say that albinos lack the gene that produces melanin.
Another example, before we move on to the heart of the question of some kind of proximate cause of homosexuality. Take height. If you have been to Europe or have been in a really old (older than the 19th century) building, you might notice how low the ceilings are. In London, one might think that one has stepped into a village of Tolkiens’ hobbits. But you know better and you realize that the average height of people really was shorter than Westerners are today. Why? It is not, as intuition might suggest, because humans have evolved such that the average height for European women has increased from just under five feet tall at the start of the Industrial Revolution to around five-foot five-inches at the start of the Information Revolution. Rather, what has happened is that people in the West eat much better, are exposed to far fewer childhood diseases, and generally are healthier as children and growing adolescents than they were a few hundred years ago. What that has created is a situation where human height has been allowed to increase closer toward the maximum allowed for by our genes (which code for the proteins that make up calcium and muscle mass). So, lurking within the genes of your long lost relatives from the Old Country was the potential for a five foot ten inch woman, but chances are very few of your ancestors grew to that height. However, because you are fortunate enough to have been born in the Twentieth century, your genes had more of an opportunity to express them.
This is what biologists mean by gene-environment interaction and I hope that my two illustrations shine some light onto how these factors dance together.
So, back to the central question. Is homosexuality genetic? Most probably yes and not entirely. Since sex, desire and romance happen primarily in the brain here is my speculation. There is probably some sequence somewhere on our chromosomes that causes a particular protein to either express or not express while the fetus is in utero. The mother’s body, responding to this chemical presence turns on or fails to turn on some other chemical cascade that results in the brain forming in such a manner that the person, when their sexuality really kicks in, has a predisposition toward homosexuality. Because of the social stigma placed on homosexuals, the individual with this particular genetic-environmental mosaic then has some variety of responses to their emotions and at some point, hopefully, comes out and accepts themselves. That’s the best answer I’m comfortable giving and I’m sticking to it.
All of this, however, begs question number two. So onto that issue.
Passing through the sieve—Does Darwinism preclude homosexuality being genetic?
If you are not willing to concede that Darwin might have had some clue as to what he was talking about then not a great deal of this will make sense. Again, because I feel the need to own my own bias, I will say that I’m an absolutely unrepentant Darwinian. I think Darwin had one of the best ideas anyone has ever had and I know that, to use the phrase of one eminent biologist “nothing in biology makes sense except in light of evolution”. So, if we accept that there is probably some level of genetic component to homosexuality then it begs the question of how it could survive the ruthless winnowing of natural selection.
I’m going to suggest a hypothesis, and own that it is only a hypothesis but one that makes the most sense to me. Homosexuality has passed through the sieve of evolution not because it, in and of itself, is adaptive but because whatever genes that influence homosexuality are themselves adaptive when expressed in a certain kind of body. By adaptive, I mean it in a very strict sense, namely in the sense that it enhances the reproductive fitness of whomever is carrying that gene. Reproductive fitness simply means whether or not an organism leaves around more descendants than someone else.
That’s just one possibility but it is the one that makes the most sense and doesn’t get into the messy (and discredited) arena of group selection.
That said, let’s remember that being homosexual does not preclude reproduction and so there’s still potential for whatever genes ‘for’ homosexuality to pass through generations in that manner. Lastly, it is important to remember that, according to what is called ‘kin selection’ one need not reproduce oneself in order to benefit one’s genes.
If one is a sibling (or a non-identical twin) then one shares one half of your genes with your siblings. This means you share a quarter of your genes with their children. So let’s say your sister has four children, you have none. Something happens to your sister and you raise her children, you have now ensured that four times the amount of your genes will pass on to the next generation than you otherwise would have. So, even if homosexuality really were a reproductive dead-end it would still have any number of paths it could take from generation to generation.
Where the rubber meets the road—What does all this mean for gay rights?
So, having demonstrated that homosexuality really could pass through the merciless sieve of natural selection and having presented a plausible (although almost certainly too simplistic to be accurate) model of what might cause homosexuality we leave the relatively non-controversial arena of biology and enter the world of politics and culture. We have come to question #3: If homosexuality is proven not to be a choice, what does that mean for the gay rights movement?
One answer is that it might not mean anything at all. Those who are against gays and lesbians existing are going to remain so regardless of any findings of science. But for the larger society, what might it mean? As a rule, in America we have the idea that we are compelled to be tolerant (in both personal and legal matters) of those who have an inherent difference. Homosexuality is probably inherent enough that to speak of any ‘change’ is quite meaningless. However, does that mean that if a smoking genetic gun is found the NGLTF can close up shop and go home? Probably not.
What it might mean is that parents might not guilt trip their children when they come out. Schools would be compelled to not tolerate harassment of gay or lesbian students in the same way and for the same reasons that they cannot tolerate harassment of Latina or Chinese students. Businesses might become compelled to not fire homosexual employees because they are homosexual. It might even create the circumstances for full recognition of same-sex marriages. However, it would be a mistake to think that the entire architecture of heterosexism will come tumbling down should some biological Einstein come up with a gene-environment interaction that survives the scientific vetting process.
Although I understand the desire for us, as gay and lesbian people, to once and for all put to pasture the idea that we ‘choose’ our sexual orientation I would suggest that, perhaps, we are missing a point. Religion is ‘chosen’. No one is born Catholic and yet we protect Catholics from discrimination in employment, housing, etc. We are very right to do so, so it is not ‘choice’ qua choice that has created the circumstances we face. It is some other cultural baggage that we need to address.
That said, finding the smoking gun would be a triumph of biology. Understanding why some people are gay or lesbian would shed light into the whole arena of human sexuality. And, perhaps, the discussion of gene-environment interaction will finally put the tired and outdated ‘nature’ versus ‘nurture’ debate out to a well-deserved rest in the pastures of intellectual history.