I think a difference should be noted. Eye and height color may be genetically caused with not much that can be done with it; however, homosexuality may have a genetic predisposition, but that does not mean one's genes mandate (no pun intended) that one be a homosexual.
I know a few gay men and they all say that they resisted homosexuality throughout puberty and tried heterosexual relationships, including sex, but in vain. I don't know if it is a predisposition or biological, but I believe many gays are gay more for biological than environmental reasons.
Speaking for myself only -arguing either way would necessarily require "proof". My position is that it is possible; however, UNLIKE a belief in God -such possibility requires proof...
I myself strongly oppose setting aside conventional wisdom, tradition, common law and enacted law based upon a leftist faith in homosexual sex that is premised in junk science and imposed by an activist judiciary...
It is interesting - at this point the conservatives seem to want to argue that homosexuality is chosen and/or environmental while the liberals argue that is genetic or predetermined, so to speak. You make a good point, orientation and behavior are two different concepts. We can be attracted to all sorts of people, objects, whatever, but that doesn't mean we have to act on it. Hence, I think behavior almost always is a choice. Sexual orientation? At this point is appears to be both biological and environmental. One common misconception that people have is that if a trait or characteristic is determined by an experience or the environment it is easier to change. This is not necessarily true. We are born with somewhat undeveloped brains and our brains continue to develop via interaction with the environment. Therefore, early experiences can shape our brains in ways that very difficult to change later on. Perhaps children are born with a genetic predisposition toward homosexuality and then some critical childhood experiences (or lack thereof) lead to expression of this predisposition. One interesting line of research would involve studying those with the "genetic predisposition" who become heterosexual in orientation. Are there certain childhood experiences that may prevent homosexual orientation among vulnerable children?
As they say if you tell a lie often enough it becomes the truth, and no one knows how to lie like a homosexual propagandist.
"I can't comment on the particular study being debated, but I think that conservatives (like me) may be begging the question when we argue strenuously against a biological basis for homosexuality."
You are correct. "Queer Theory" advocates argue against biological basis and says it is cultural. "Environment" is actually the liberal position on many things, eg, Freudianism, whether IQ is inherited, etc.
Anyway, NARTH is hardly unbiased themselves. Take grain o' salt in critiques.
"We should concede there may be -- may be, not is - a biological basis for homosexuality, and then we should add, "So what?" There may be a genetic basis for alcoholism, but no (sane) person is arguing that alcoholics should be allowed to show up at work drunk."
And then bare the double-edged sword to this whole silly leftist 'science' project, one that makes the liberals cringe,
"And if they do discover a 'gay gene,' wouldn't that be awful for the gay community? Just imagine all those breeders aborting kids with the gene to ensure grandkids..."
Then they have to decide whether they'd then choose between abortion rights or gay rights. Their heads will explode.