>>34459582Just because something seems like it could be explained as a genetic advantage, doesn't mean that's the reason or explanation around it. Unless you believe there's a conscious force behind (who's intentions you also understand) these "just so" about evolution don't really hold any weight. Using something like genetics/evolution to explain, then interpret peoples behaviors is basically impossible to justify with our current understanding of both.
I could say with just as much confidence that the reason people generally aren't attracted to siblings (or parents) for that matter, is because they went through a large part of their pre-sexual development with that sibling, and likely bathed, intimately touched, etc. that sibling, but not in a sexual way. Either since sexuality isn't developed those things with siblings get discharged and arousal wouldn't cross a grown person's mind. Alternatively, you could argue that at a certain point of their growth, they're told those kinds of experiences are bad, which in turn leads them to suppress those desires through development, so it again, isn't even a consideration when they're grown.
I find it extremely hard to believe that outside of the child rearing stages, there are any strong biological traits that avoid incest. If someone never met a sibling, but saw a picture of them for the first time, or met them for the first time, never knowing they were related they're not likely to react any different to any other stranger.
