One thing that we must understand is that when looking for a historical origin of something we must look past the way things are today. Yes, today when tend to look at things objectively or in terms of "me" and "them". However, this way of thought is a fairly new one which was introduced to the world by the group of people who call themselves "white". In the cultures of the people who in this society are considered "non-white" people it has been an understood fact that we are cosmic beings connected to all things. We are all part of a whole with no part existing without the other. What the "white" group did was to begin to seperate things and pit them against each other. Even the human being was divided and each divided part were said to be in conflict(such as reason vs. emotion, mental vs. physical, etc.). While in other schools of thought balance and harmony was looked at as two parts coexisting equally, the "white" group's way of looking at it was that harmony was achieved when the "better" part conquered the "lesser" part. This way of thinking, while already existing in this group's thought, was put into words by Plato, one of the Greek culture's "greatest" philosophers.
Now the question is where did this way of thinking come from? One theory is that it is due to the harsh climate that the "white" or melanin recessive people lived in for some time. It is stated that due to climatic situations such as the "Ice Age" (which they give the impression was all over the world in school when that is not possible) which are not conducive to life and are harsh, hostile, and deadly, a mindstate was born from that which was equally as hostile. You see, if your environment is nourishing and giving then you tend to follow that pattern as well, but if your environment is want that is hostile towards life then you will develop a hostile way of thinking. I've got more to say, but there's a storm going on and the lights are blinking so I'll send this for now.