Most current views of homosexuality regard it as a combination of nature and nuture.
Quite a few of the compelling psychological arguments have been brough up already.
As for biology, Wikipedia has a brief summary of
a few common biological theories.
http://en.wikipedia.org/wiki/Biology_and_sexual_orientationJust a few comments:QUOTE(Hey Hey @ Dec 21, 2006, 12:47 PM)

Homosexuality occurs widely in the animal kingdom ...
That's not exactly true. It does occur, but it's certainly not widespread.
QUOTE(Technologist @ Dec 26, 2006, 02:18 AM)

I think that if everyone avoids the tendency to make this a values debate, then the dialog could serve a useful purpose.
The value laden comments are
not utterly useless. They can still teach a bit about human behavior and society (a bit off topic maybe).
Most posts on this forum seem to be fairly unbiases, yet I swear this topic has more value-laden comments than any other I've read. What is it about homosexuality that makes it
so taboo? I really am curious why this subject strikes such a strong chord with so many people.
QUOTE(lucid_dream @ Dec 26, 2006, 05:50 PM)

Get real. Intelligence, neuroticism, and autism have nothing to do with homosexuality.
Well, that's not exactly true either. There are actually strong correlations for intelligence, neuroticism, and homosexuality.
Correlations say that intelligent individuals are more likely to be homosexual. However, I believe it's quite possible that highly intelligent individuals are simply more likely to
admit homosexuality. So, the actual incidence rates of homosexuality may not be correlated with intelligence. Yet, of course, correlation does not imply causation...
QUOTE(lucid_dream @ Dec 21, 2006, 12:55 PM)

Heterosexuality leads to propagation of the species and hence fits into the big picture. Homosexuality does not, and only produces sexual gratification for a select few "homosexuals".
Be careful not to oversimplify evolution and natural selection.
Here's a scenario to illustrate the complexity:
HypothesisIt's quite possible that homosexuals are the byproduct of evolution/genetics.
Maybe sexuality is influenced by a spectrum of genes (polygenetic inheritance). Well, that could easily produce a spectrum of phenotypes ranging from totally heterosexual to utterly homosexual and everything in between. Psychological factors could then expand this spectrum.
And when I say spectrum, please do not think of the Bell curve. Not all natural traits assume this ratio of incidence.Selection FactorsWhat if bisexuals are favored because of their ability to "bond" with their peers. No selection of homosexuals (or heterosexuals) would occur.
Of course, we know that society applies selective pressure on heterosexuals.
Well, these two selection forces may very well oppose each other.
Yet, bisexuals could (and do) appear heterosexual so as to avoid the societal pressure.
What does this mess lead to?
- A large proportion of heterosexuals
- A large proportion of bisexuals functioning as heterosexual but passing on homosexual "genes"
- A small population of homosexuals
See how complex that can be? That's even a simplified version. (It's probably more complex than simple polygenic inheritance.)
My personal opinion:
I'm inclined to believe that the underpinnings of homosexuality are biologically based. But I also believe that environment plays a
huge role.