A commenter over on Ed Brayton's blog, responding to yet another yahoo insisting that gays decide "(yes, DECIDE)" to be that way, drew an analogy to being left-handed, pointing out that most people nowadays accept handedness as an innate trait that stubbornly resists efforts to change it. It doesn't take much poking around to find that while geneticists have the handedness gene sort of surrounded, more or less, with a vague idea of its chromosomal location, they do not, in fact, have the little bugger tied down yet.
Like many traits, handedness is probably determined by a complex interaction between genes and the environment, experts figure.Left-handers are more likely to have a left-handed relative. But researchers have yet to find the gene or set of genes that pick one hand over the other.
Most scientists agree that handedness exists on a continuum. The idea helps explain why some people bowl with their left but hold a spoon in their right. Truly ambidextrous people, who have indifferent preference for either hand, are extremely rare.
Hmmm. So we have scientific acknowledgment of a handedness continuum, but no "left-handed gene" identified... yet no rational person would argue that the roughly ten percent of the population that is left-handed consciously chose that trait. No rational person would support elementary schoolteachers returning to the days when lefties had their hands slapped or tied behind their backs in an effort to force them to use their right hands--you know, to be normal--because we recognize that handedness is innate and cemented at such a young age as to be unchangeable, and, equally important, that attempting to change handedness is traumatic and largely pointless.
Then I thought about other preferences. Favorite flavors, favorite colors, temperatures at which people are most comfortable. I can't stand olives or anise, despite numerous attempts to enjoy them in different preparations. Gotta try new foods eight times to be able to like them? They just never took with me, despite dozens of attempts and the fact that most of my relatives adore olives. On the other side of things, I love high-cocoa-content dark chocolate, and cilantro by the bushel--two intense flavors many people don't like. And what's the usual extent of the conversation about such things?
Do you like this?
No, I do not.
Have you tried it?
Yes, and I do not like it.
I do not like it either, but my sister does.
Is a proven genetic component required before the average person will consider handedness valid? Of course not. What about flavor and color preferences? Of course not. De gustibus non disputatum est is one of the most under-recognized guiding principles of our society... unless you're talking about sexual preference, of course, which requires a unanimously concurred upon genetic pedigree before many people will treat it like a hundred other innate traits they never give a second thought to.
You can choose to try anise or cilantro if your parents or dinner host ask you to. You can choose to try men or women if your parents and society expect you to, but when you are not innately oriented toward the opposite gender, all the experimentation and intentions in the world won't make a difference in the result. Some tastes can't be acquired.