[bermanoid]

Ah, you're absolutely correct, I did misunderstand what you were saying - indeed, your argument is a classic example of kin selection, I'm just so used to hearing group selection arguments that I jumped the gun [1] (when I wrote "given your comment above, I'm surprised that you would make this argument" that should have been my first clue that you did, in fact, know better). You're 100% right that help-out-those-with-the-same-genes altruism is not only possible, but expected, and your argument makes perfect sense in that light.

Personally, my suspicion is that homosexuality is more directly linked to a positive physical trait in the individual, though I don't have much to really back that up other than a vague sense that kin selection effects in evolution are rarely as strong as direct expressed ones. But yes, the "gay uncle" effect could explain it, too, and it's definitely an interesting enough phenomenon to be worth keeping in mind.

[1] In fact, I probably shouldn't react as negatively as I do against most invocations of the group selection argument, because oftentimes the points would be valid if expressed as kin selection arguments instead.

[dalke]

Whoa! There's agreement on the internet! :)

[bermanoid]

Being proven wrong once is worth being right a hundred times; it's only when we realize we're wrong that we learn anything useful. In this case, I was reminded of an evolutionary fact that I hadn't thought about in quite a long time, and that's fully worth being wrong.

In theory, agreements should be more common than they are (sadly) in practice: http://www.scottaaronson.com/papers/agree-econ.pdf

What I've always wondered is which particular assumption of Aumann's agreement theorem is usually lacking on the Internet: honesty, rationality, common priors, or simply the willingness to continue the conversation long enough to resolve the disagreement.

[dalke]

I lean very much against the idea of rationality, in the precise economic sense used by Aumann and others. I find the work of the behavioral economists more believable. I believe there is some truth in the saying that the only people who make economically rational decisions are economists and sociopaths.

BTW, in this thread I learned that I need to be more careful about how I use the term "population." :)