Another Theory

"I know I'm not perfect.  I'd be the first to admit that; but I guess I think my outlook on life is pretty sound, probably more balanced than those about me."

"My family is not perfect, we know that; but the way we do things is probably better than the way other families do things."

"My culture is not perfect.  It's made lots of mistakes.  But when you look at other cultures about, it's apparent it's not that bad."

These are the roots of prejudice and arrogance.  Given a disparity in power and opportunity, this leads to racism.

The equation goes, prejudice + power = racism.