Gayle Madwin (queerbychoice) wrote,
Gayle Madwin

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Epigenetics: The Latest Explanation for Why Straight People Are Straight!

There's a new study in the news lately that attempts to attribute sexual orientation to DNA. As usual, this study is being presented as an explanation for why gay people are gay, because straight people don't seem to think their deficiency of gayness requires any explaining. But this study differs from a lot of past studies in that it attributes sexual orientation not to any differences in genes but rather to epigenetic changes (caused by one's environment or one's parents' or grandparents' environments - such changes can be inherited for a few generations but eventually disappear) that switch certain genes "on" or "off."

Perhaps you might expect me to welcome this new round of news articles. After all, they're not asserting that people are necessarily born gay! They're saying that people's social environments (or possibly their parents' or grandparents' social environments) made them gay! But mostly I find it all just as irritating as ever.

The scientists studied 47 gay men who had identical twins. Scientists who are trying to explain why gay people are gay always seem to prefer to study only men, and I think this is not only for the usual reasons that scientists who study practically anything seem to prefer to study only men, but also because in our current society, men are easier to divide into gay and straight than women are. Anyway, of the 47 gay men they studied, 10 of their identical twins were also gay, and 37 of their identical twins were straight. This is a 21% concordance rate, which is widely interpreted to mean that sexual orientation is partly genetic, although I dispute that interpretation - to me it seems obvious, in a society in which sexual orientation is so widely perceived to be genetic, that having an identical twin who identifies as gay is going to cause a whole lot of people to start questioning whether you're really gay also, which is going to cause people to start questioning their own sexual orientations at much higher rates than they would have done if they didn't have a gay identical twin, which will naturally lead to more such people eventually identifying as gay.

But that wasn't the focus of this particular study. The focus of this particular study was epigenetics, not genetics. So the scientists took saliva samples from these 47 gay men and their identical twins and studied the epigenetic markers of the DNA in their saliva. They found five differences in epigenetic markers which, when considered together, could "predict" the sexual orientation of these men 67% of the time. (Or, more specifically, to predict straight men's sexual orientations with 50% accuracy and gay men's sexual orientations with 83% accuracy.) ("Predict" is the word generally being used in the news articles, though I think it's a misnomer since the scientists used their pre-existing knowledge of these men's sexual orientations to identify the five epigenetic markers. To actually "predict" anything, the scientists would need to look for these five epigenetic markers in a whole new population of men whose sexual orientations they didn't already know and use the markers to predict the men's sexual orientations. The scientists did not do this.)

One of the problems with this study is that the epigenetic markers in the DNA of a person's saliva are not necessarily the same as the epigenetic markers in the DNA of a person's brain - and even the epigenetic markers in the DNA of a particular brain cell may be different from the epigenetic markers in an adjacent brain cell - so trying to study the influence of epigenetics on sexual orientation by studying DNA from saliva rather than DNA from the brain is kind of like trying to study, say, racial differences, without having any actual information about the race of the people you're studying, but only knowing some vaguely related information such as the races of people's favorite singers and actors and athletes and authors and such, and deciding to just assume for the sake of convenience that people's own races can be estimated by averaging out the races of their favorite celebrities. (I tried to find information about exactly how much epigenetic markers vary between different cells and different tissues in a person's body, so as to try to select a highly accurate analogy here, but it seems to depend on which specific epigenetic markers we're talking about, so I couldn't find a simple percentage of variation to work with.)

But another problem, which to me is even more glaring, but which seems to be getting even less notice in most news articles, is that correlation does not prove causation. Saying that epigenetic changes correlate (with 67% accuracy) with men's sexual orientation is simply saying that the social environments of gay men tend to be different from the social environments of straight men. Well, duh. Straight men are not so often found in gay neighborhoods and gay bars and gay bookstores and so on . . . and, more to the point, straight men are not the targets of homophobia. (At least, not as directly as gay men are.) The LA Times article states, "Researchers working in the young science of epigenetics acknowledge they are unsure just how an individual's epigenome is formed. But they increasingly suspect it is forged, in part, by the stresses and demands of external influences." Who would ever guess that gay men might experience different stresses and demands of external influences than straight men? None of the journalists reporting on this study would ever guess that, it seems, because they all seem to assume that the epigenetic differences between these men caused the men to have different sexual orientations, rather than their different sexual orientations causing them to suffer different stresses that caused different epigenetic changes. Have these people never spoken to any gay people in their lives? Ask a hundred gay people whether being gay had a significant impact on their lives. I'm pretty sure you'll get more than 67% saying yes.

I'm just frustrated by this continuing focus on searching for something that makes gay people gay, and the assumption that gay people want their (our) gayness to be explained away and excused on "it's not our fault!" grounds that imply agreement with the notion that gayness is a fault. I noticed that Dr. Tuck Ngun, the gay postdoc who led this study, has announced that he is leaving the field of academic research because "It kind of, honestly, became a little bit troubling to me, what I was actually doing . . . Having done this now, I could sort of foresee a not-so-happy outcome." It's not clear precisely what disturbed him - maybe he was worried that his study could be used to eradicate gay people? - but I think there's plenty of reason to be disturbed by the way the study is being reported. There is absolutely no reason why this study should be any more frequently interpreted as "Big News! Here's What Makes Men Gay!" than as "Big News! Being Gay Impacts Men's Lives!" but the former interpretation is the one getting all the journalistic attention. Why is that? The latter interpretation seems to me much more valuable for gay rights than the former. We should be talking about the fact that being gay impacts people's lives. The impacts of homophobia and heterosexism on people's lives are the central issue that the gay movement ought to be educating people about. The entire question of "But why are people gay? And can we make them prove it scientifically rather than just asking them?" is a distraction that takes the focus off examining homophobia and puts the focus on implying that people need a biological excuse to be allowed to love whoever we choose to love.
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