Genes and Epigenes

In sexual orientation. Interesting video from National Geographic that summarizes some of the findings on the role of genes in sexual orientation:



A follow-up from one of Andrew Sullivan's readers:

The National Geographic clip on twins was fascinating, not least for the language it used. At eight weeks, the clip says, the brain of a fetus with a Y chromosome is bathed in testosterone. "Not enough, " it hypothesizes, and the brain isn't sexualized to be attracted to women. The clip doesn't say if a fetus without the Y would receives 'too much' testosterone or 'not enough' estrogen at eight weeks to develop a same-sex attraction.

Later, the clip speaks of switches in the brain causing disease, and it flashes back to the gay twins as it emphasizes the word 'disease,' visually implying the gay twin is diseased, the straight twin isn't, because of the way the switches in their genes were activated. In both instances, the underlying tone is a tone of "being gay is wrong, a genetic disease." This tone, it feels to me, forgoes any question of potential gain for same-sex attraction, re-enforcing negative social bias.

I also thought it amazing that the research suggests attraction to men is the norm, attraction to women must be activated with a testosterone bath. I would have assumed the opposite, that attraction to men must be activated. (I am a heterosexual woman.)

This lays bare one of the pitfalls of popularizing science: the "not enough" testosterone comment would perhaps have been better phrased as "below a certain amount." The reader's objection to the assumption of normalcy in heterosexuality is legitimate, I think, although I think the "disease" comment is stretching a little -- I didn't get that impression at all when I watched the video, and I was looking for it. Sullivan comments:

Describing natural phenomena that are not of the norm, without describing them as somehow defective or diseased, is difficult given our cultural inheritance. I don't think all of it can be called bigotry as such; most of it is simply driven by majoritarian default assumptions. Freud saw homosexuality as not normal. But he didn't draw any "disease" assumption from that and saw heterosexuality as equally worthy of explanation.

What I see over and over again in these discussions regarding "normal" is another example of sliding definitions. In psychology, "normal" describes a range of behaviors, not a specific behavior out of a group. Therefore, it is perfectly legitimate to say that same-sex orientation is as normal as opposite-sex orientation; it is not legitimate to describe it as "abnormal" in any way.

One mistake that Freud's followers made -- not Freud himself, as Sullivan notes -- is that they consigned same-sex orientation to the realm of pathology, at great cost to their patients. There was no real support for it, and in fact, every reason to be wary of it -- they were dealing with populations that were, by definition, in emotional difficulty. It wasn't until the work of Evelyn Hooker in the 1950s that anyone thought to consider the vast majority of gays, who are happy, well-adjusted people.

As it stands, this summary confirms what I've been saying for a while: if you're looking for a "gay gene," give up. There's probably isn't one, because the genetic basis of human behavior is much more complex than that.

Timothy Kincaid at Box Turtle Bulletin also ran this video with a short commentary. The comments are worth checking out, if you can scroll past the flame wars.