> You could make this statement about any group at all.
Yes, that's the point > And then once you realize people are in multiple groups, the whole thing devolves into chaos.
You have bad priors. That would only happen if groups could only have singular and simple goals. It requires those goals to be mutually exclusive. Because as soon as they overlap, even just a little, cooperation becomes an effective strategy.Hell, history shows us enemies often cooperate. Mostly to defeat a mutual enemy, so they can go back to fighting each other, but that's still cooperation