Like They Do on The Discovery Channel
by Richard Gant
April 21, 2017
Now, as I've had to say with distressing frequency thanks to the topics I choose to write on, Skeptoid is not a political organization. We're not here to tell you to vote one way or another, or to back any specific candidate or party. That's not what we do. Sexuality is a highly politicized topic, but we just look at the evidence, and encourage you to do the same. So, with that in mind, let's examine the question:
"I was born this way, born this way"?
There is some evidence to support Lady Gaga in the idea that homosexual and heterosexual attraction has a biological basis. For example, "A Genetic Study of Male Sexual Orientation" (published in the December 1991 issue of JAMA Psychology) documents that among monozygotic (identical) twins, if one twin is homosexual then 52% of the other twins were also homosexual. This dropped to 22% for dizygotic (fraternal) twins and 9.2% for non-twin biological siblings. (Curiously, adopted siblings had a 11% concordance. Go figure, right?)
In 1993, the Archives of Sexual Behavior published "Homosexual orientation in twins: A report on 61 pairs and three triplet sets," a similar paper that examined both male and female twins (although they still had more male than female pairs). The authors found a 65.8% concordance for homosexual orientation among monozygotic twins, but only a 30.4% concordance rate among dizygotic twins. In the words of the authors (from the abstract, as the full article is behind a paywall): "These findings are interpreted as supporting the argument for a biological basis in sexual orientation."
Let's be honest here, though. These two studies, which appear to be typical examples of studies of this nature, are not proof positive that sexuality is 100% genetically determined. But then, why would we expect it to be 100% genetically determined? Human beings, like any animal, are complex creatures with complicated and sometimes unexpected behaviors. Why should sex, out of all of that, be simple?
Binary is just a way of counting
Human sexuality is more than just "homosexual" or "heterosexual," just like human gender is more than just "male" or "female." There are at least four recognized categories of sexual orientation: asexual (lacking any sexual attraction to anyone), bisexual (sexually attracted to men and women), heterosexual (sexually attracted to individuals not of your own gender), and homosexual (sexually attracted to individuals of your own gender). There is a move, however, towards replacing the terms "homosexual," "heterosexual," and "bisexual" with androphilia (sexual attraction to men or masculinity), gynephilia (sexual attraction to women or femininity) and ambiphilia (sexual attraction to both of the former).
Regardless of the label used, all of these attractions exist on a scale. Not everyone is equally sexually attracted or disinterested, after all. One example of this is the famous 1948 Kinsey scale, which ranked sexuality on a scale from 0 to 7:
But is it natural?
Well, what do you mean by "natural"?
Sex is a behavior we engage in, after all. And we're not even alone among the primates in engaging in non-reproductive sex. Take, for example, our close cousins the bonobos. They're also known as "pygmy chimpanzees" and, along with chimpanzees, are our closest living genetic relatives. And bonobos swing in more than just the brachiating sense. They use sex for reproduction, of course, but they also use it to avoid or resolve conflict and for pair bonding. Male-female, male-male, and female-female contact has been documented multiple times in the form of genital-genital (GG) rubbing, genital massage, oral sex, tongue-kissing, and penetrative copulation.
In fairness, our other cousins—the chimpanzees—don't behave like this. Homosexual pairings have rarely been observed (if at all, since I couldn't find any examples) among Pan troglodytes. The chimps are a very male-dominated species, with a dominant male gathering a harem and denying reproductive access to other males (who will still try and mate in secret). Which, if you're in a particularly cynical mood, sounds as much like human sexual behavior as anything the bonobos get up to.
At the end of the day, of course, sex is about far more than biology and evolutionary history. Culture is our evolutionary mechanism right now, and it has a lot to say on the subject. But that's a matter of ethics and personal choice, not biology. And nothing in our biology says that Homo sapiens sapiens as a species is inherently a Kinsey 0.
by Richard Gant
@Skeptoid Media, a 501(c)(3) nonprofit