I keep wondering if the keystone is a belief system, especially shared beliefs. To oversimplify, one group believes they are destined to rule and the other believes they are to live in harmony with others. One believes the 10 commandments are for the foolish to follow and the other believes Moses gave them rules for happy lives. One group is born with a genetic makeup that enables ruthless action because they have no empathy, (https://www.drgeorgesimon.com/is-psychopathy-genetic/) and the other has concern for others.