Out In The Mountains : Health & Wellbeing - Orientation of the Species

Among psychological researchers, a feisty debate currently rages over the nature of differences between women and men. There is passionate disagreement as to ‘why.’ However, there is practically no controversy about the ‘what’ – when viewed as a group, men and women are different.

These differences cannot be explained away. They have a magnitude comparable to the range of psychological variables deemed worthy of study. People’s gut sense about these differences are comparable to, not an exaggeration of, their most reliably measured magnitude. And they are not, it seems, going to evaporate any time soon.

Groping for a theory to explain the gender gap, one camp blames reproduction – the often distasteful notion that ‘biology is destiny.’ From the process of procreation onward, women and men do not exactly ‘share’ this burden. While the boys go hunt and carouse, women tend to the hearth and keep an eye on the kids. Over the ages, ‘good’ men – that is, the ones most likely to survive and reproduce – do, while ‘good’ women do everything else.

This may describe the way things are now, and perhaps the way things were then. But as the other side points out, bolstered by persuasive evidence, it may be the other way around: powerful cultural habits mold us into what seem like two separate species.

Who’s more right? We don’t know. The causes of causes are elusive. However, better descriptions are instructive and useful. And the causes of sexual orientation are not as murky as you might think.

Running in the family

In previous months, I discussed how behavior genetic research describes groups of people in an informative fashion. The dependable genetic qualities of twins – both identical and fraternal – give us enough known variables to set up a sort of algebra equation where we can solve for the rest. Variations are parsed into estimates of the relative influence of environmental and genetic influences. By examining careful samples of a population – say, the entire state of Missouri, where I get a lot of my data – then we can have some confidence in the results.

In the case of sexual orientation, these results are intriguing. For men, it seems that genetic influences account for about half the variance. This means that, unless you are going to entirely discount the laws of probability, the evidence does not support the ‘choice’ argument: to a large extent, gay men are born that way.

For women, however, the evidence is quite different. Many lesbians may share gay men’s firm conviction that their sexual desires are deeply felt, and not a conscious choice, and that may indeed be so. But independent of such beliefs, lesbians are made more than born, while for gay men it’s the other way around.

The proof, here, takes us back to twins. Identical male twins are more likely to both be gay than fraternal male twins. With females, it doesn’t matter: twin girls of both types end up the same sexual orientation at basically equal rates.

Looking beyond twins to families, men and women share something here, but with radically different implications. Being gay does seem to run in the blood, but on the mother’s side only. The evidence suggests something on the ‘X’ chromosome, which, you’ll recall from junior high biology, means it’s part of mom’s genetic contribution.

Thus for gay men, there’s a much higher chance that, along with your brothers, twin or otherwise, your uncle – on mom’s side – is also that way, and the same is true for granddad, too.

What’s more, men tend to identify as straight or gay and stick to it most of their lives. Bisexuality is far less common for men than for women. And for men, the different aspects of sexuality tend to be more consistent: fantasies, attraction, sexual behavior, and self-identification most often line up either homo or heterosexually.

Different for girls

For women, though, the family picture’s both different and the same. If you’re a lesbian, then about six percent of the time, so is your sister (only one percent of straight women are this lucky). But nearly a third of the time, when it’s true of the daughter, it’s that way for mom as well. While moms and daughters may always share half their genes, as a group, so do sisters – and remember that in the case of identical twins, they’re the same. Yet the coincidence of lesbianism between sisters versus mom/daughter is so very different.

As many know from their own experience, it’s often the daughter who comes out first. Maybe lesbian moms somehow teach their daughters to follow their hearts, even when they don’t take their own advice. This may include those internal dimensions of attraction and fantasy, which tend to vary more for women – bisexual, straight, and lesbian – than for men. If culture didn’t tend to discourage men’s inner lives, then maybe we would be more attuned to those soft urgings drawing us to the more fluid sexual identity women enjoy.

Dean Hamer and Peter Copeland described a vivid example of such fluidity in Living With Our Genes. During Hamer’s research, an older woman they called Margaret reported that, in spite of two satisfying marriages and no sexual experiences with other women, she predicted her next lover would be female. ãYou know, I may be 68, but I’m still interested in sex. And you may not know this, but the men in my age range are pathetic. So I assume that my next lover will be a woman.ä

Now does she sound like fun or what? Like so many women who transition in and out of sexual identities, Margaret’s flexibility is admirable (along with her salty humor). But maybe, even for women as a group, it’s also unusual. Most women (and men) start out and stay heterosexual. It seems the rest of us do it differently depending on our gender.

Still no recipes

If learning to be open to the world is the first step toward lesbianism, then the religious fundamentalists may be on to something. Parenting that encourages girls to be independent may opens more of them up to a range of options – sexual and otherwise. If, in a general fashion, teaching girls to resist conformity leads more of them to a lesbian identity, then I shudder to think about how it might be prevented.

For boys, and for reasons that do not fit very well into any theoretical scheme, we can say with some confidence that ‘it’s genetic.’ But although some interesting preliminary work has provided some details, they are a long way from implying any sort of intervention, the dreaded type of prenatal testing that might predict a boy’s adult sexuality.

Although some small studies have found the right sort of preliminary evidence, the results are not quite conclusive: many of the gay men lack the ‘critical’ gene, suggesting more than one is operating on sexual orientation. Moreover, how any number of genes operates in this regard leads to further questions. What exactly do they do? Does it involve hormonal regulation or some other aspect of brain chemistry?

And because genes interact with the environment, and sexual orientation itself is so complex, chances are good that we’re not looking at a one-to-one, gene-to-behavior relationship. However, as is the case with other complex clusters of behavior, that does not then mean that genes are unimportant, only that the mechanisms may be impossible to fully explain.

What’s more, as I mentioned before, the sort of research that might answer such questions is probably a long way from being conducted: it’s too expensive, and the pay-off, compared with the pressing questions of detecting bona fide genetic disease, is questionable.

That’s not to say that the ethical questions posed by genetic research are resolved. But given what we know so far, I do not see a day when, like in The Twilight of the Golds, prenatal testing will reveal a child’s sexual orientation any more than it would predict her occupation. It’s just not that simple.

Larry Rudiger is a Research Fellow in the Division of Behavior Genetics,Department of Psychiatry, College of Medicine at UVM. His work there focuses on children and families.