One way groups can be classified is the naturality of forming the group.
Naturally forming groups of people acting in pure interest in other members just might be able to force out unfavorable members. Such as friend groups.
On another end there is very artificial groups. I would consider astronauts these. Enough options and time to pick out the well- fitting ones.
But on the valley there is the majority of the groups, which are grouped around agenda, be it idea, hobby or profession. Coppers, locksporters, religious groups, Swedes and men named Tom. When the focus is not in the internal nor external selection of members, but gathering around a mutual thing or task, there will be unfit members.
Thus it’s not matter of ‘if’, but rather ‘when’ and ‘how do we react?’
TL;DR: Groups with common interest are susceptible to unfit people.
Welcome to the basis of conservative political philosophy.
The psychopaths aren’t going away.
From that fact, all the rest about fearing big government, people having weapons, free markets, it all comes from that one initial postulate.
Well, the other postulate is: “knowledge is always incomplete”
The problem with the first postulate is it’s easy to ignore if one has been insulated from the psychopaths. Safety permits a blind spot with regard to the existence of evil in the world.
The opposite postulate, that perhaps psychopathy is an aberration which can be eradicated with the right circumstances, is basically the basis of progressive political philosophy.