> Because evolution is a local optimizer, not a global optimizer, and you can't account for all the factors an evolutionary process accounts for indirectly. Th

> Because evolution is a local optimizer, not a global optimizer, and you can't account for all the factors an evolutionary process accounts for indirectly. This is pretty much my point. People assume that there are some universal evolutionary principles that underlies everyones decisions across species. And that these simplistic principles can explain everyones behaviour. > I don't believe this, but if you have a reputable source I'd love to see it. Here is one from the UK https://yougov.co.uk/news/2015/08/16/half-young-not-heterosexual/ https://yougov.co.uk/news/2015/08/16/half-young-not-heterose... Someone linked to another from the US somewhere in the thread. I think it is striking how much this a generational thing. And IMHO a behaviour that is probably not hardwired in genetics.