Uhm, because of genes. Still. There are plenty of genetic states that have little or no impact on general biochemistry. Why you seem to think that one must inevitably lead to the other is beyond me.
So why are they gay? "Because of the genes" is a way too general answer. What is gayness? You say there is no difference. So why are they gay? Genes are only the blueprint. What is different in the bodies because of that "gay gene"?
I'd love to hear the answers to those question too.
First, I never said there was no difference at all between gays and straights, just that there were no distinctive
biochemical differences between them, yet readily admitted to other types of biological differences.
And the article doesn't really dispute that, now does it? It talks about different reactions
to the normal chemistry of others, but not differences
within their own chemistry itself. And those different reactions, all seem to be differences in intensity, rather than type.
So, let's return to the question: why are they gay?
Again, it's genes. To be more specific, genes which aren't causing any chemical imbalances, but which are instead determining the diversity and distribution of chemical receptors throughout the body.
Receptors are how chemicals from without actually get within the various systems of the body. If one has a lot of a certain type of receptor, one has a greater capacity to absorb and respond to a given substance. If one has few of a specific kind of receptor, the less of a corresponding substance that individual can readily absorb and thus be affected by.
Following this thus far?
And from the article, it appears as if Gay men must have a greater number of receptors for testosterone, than for estrogen, and thus react more strongly to the arousal properties of the male hormone than of the female. (Simple chemistry insures that they'd still react to estrogen, but just to a significantly lesser degree than straight men would. And, as I said before, they'd invariable channel this errant arousal toward what they actually desired.)
We can therefore infer that Straight guys likely have more receptors for estrogen than testosterone, and thus respond more readily to chicks than dudes. (Likewise, they would still have some testosterone receptors, and would thus not be entirely immune to the testosterone of other men, but this would pretty much be outweighed by their sensitivity to estrogen.)
And I'm guessing that Bi-guys likely have a fairly balanced distribution of both kinds of receptors, thus making them more or less equally susceptible to both testosterone and estrogen.
At no time does the article imply that gays have a notably different biochemistry from straight men, or that any chemical imbalances are at all involved. It's still a genetically determined state, and therefore NOT a choice, but is the result of a purely biological root cause. And it's a state that's still unlikely to ever be "cured" at any time in the foreseeable future, thank goodness.
Any questions?