I have a theory that the divides in humanity come down to the basic insecurity of a lot of people. This makes them need to belong to a group and, when they come across others who are not part of that group, they have to push their ideology forward, sometimes extremely aggressively, in order to bouy up their own ego.

This can be taken advantage of by the real egotists and sociopaths who feed off of the adulation and compliance of their followers.