On to the posts!
With monozygotic twins, the chances of both being homosexual are 1 in 2. For non-twin siblings, the chances are 1 in 20.
Anyone who can say that supports a finding of "no correlation" is either completely incapable of understanding objective scientific studies or is simply and unabashedly dishonest.
The point that I have never seen raised in any of these twin studies is that identical twins raised by the same parents are normally raised far more similarly than fraternal twins or non-twin siblings. That is, the nurture part of the equation can still be counted on to such a large degree that the nature part cannot be established. (After all, the identical twins wear the same clothes, have the same experiences, have the same expectations etc. It's highly likely that if one is molested the other will be also.)
Now if someone's done a study of sets of separated identicals raised in similar households (that is each twin raised in a household similar to yet separate from his twin) and sets raised in dissimilar households then maybe we'd get some better data. As it is however, with identical genetic material, if one was 'gay' I'd expect the other to be also. This is not the case in any study.
If any one knows of some such study I'd be inetersted in seeing it.
I can hear tdadams now: "Not this again". Yes, he dances well doesn't he.
Some libertarians make a lot of sense in some ways, but when it comes to issues of morality it seems as if they haven't thought their position all the way through. And that's why they dance around answering questions which comes across as obfuscation. At least that's how I see it.