Race does not separate people so much as culture and religion which are basically loyalties to old ideas. It is human nature to seek an identity and to make generalizations like stereotyping and it takes a lot of education in an enviroment that encourages free thinking to overcome natural and ritual predispositions and then greed and politics as well.
The road to understanding and tolerance is long and trecherous one for humanity. It has only taken but a few steps in its journey to enlightenment. We can only hope that we don't engineer our own demise before we can see our way to world peace.