I feel this is far more primal than we might think. That it’s wired into some people that everything has to be about, “how does this benefit me?” And I think this would be unsurprising. That sounds like a healthy evolutionary trait.
I think there are people that for one reason or another can overcome this instinct and see a bigger picture of society.
And I think these groups generally coalesce for reinforcement and forms of ideological security. Then they give these groups names.