It's probably in our genes. Safety/strength in numbers.
Throughout history. You have the rulers and the followers.
It starts as children on the playground, then into adult workplaces, clubs, societies (both secret and not), religious groups (which are rather like large clubs) and so forth.
To belong to some, you, as an individual, choose to join.
With others (as in elite groups), you, the individual, must be accepted by that particular herd. Meet their requirements/standards whatever they may be, such as social/monetary standing, intellect, affiliations, etc.
It's the way of the human world.
It has always annoyed me. How can there ever be true and complete equality when we continually pick and choose whom/what is or isn't our equal? *sigh*
I guess, in the big picture, we are all part of the herd of humankind?
But does being 'part of' the whole necessarily mean 'belonging to' it?
Chchch...choice or chosen, turn and face the strange....and humans sure are!