Great question and very important one in out time and age. It is so unfortunate that we can advance so fact in every area of life except our own human nature.
When I was little growing up in the 'close to other world' tiny Communist country in the Eastern Europe, where people of other nations not to mention other races were very rare, I realised that my Grandmum's negavite attitude towards different people is based on ignorance. I also believe that old Christian representation of Jesus as a white man and representing evil in black colours helped to make wrong associations in my Grandmum's head. Believe she was the kindnest, very religious and
trustworthy, caring person you could every meet, however she was scared of other races based just on her ignorance.
Once I managed to leave my Communist country behind, I realized that there are still many 'racists' in open multicultural western world,
I wondered why? I have met many white people who lived in South Africa in the time of apartheid, they never shook of idea of supremacy of whites, just because it helps them to feel more important. It shows their own lack of selfesteem and selfworth.
I meet a lot of Eastern European migrants who fled their poor countries in the pursue of materialistic goals, which many of them have not manage to meet. They feel ashamed and the colour or race is the only one last thing it makes them feel superior.
Sometimes awareness is not enough I sadly realized some people do not want to change their attitudes because just than would nothing left for them to feel worthwile.
I am so happy that great people like Mandella, Gandhi...Obama exists and manages to succeed in spite of so many odds built on this superficial theory that one race is better than other.