Well, I suppose any group with assholes (which is every group) is bound to have areas where the proportion of assholes to the rest gets higher.

Could also be rural vs urban vs suburban areas applying different social pressures that drive individuals into seeking that kind of artificial “family”.

And, once you have a threshold of assholes, that by itself encourages others in a group to either be assholes too, or get pushed out, leaving the group itself to draw in assholes to replace them.