This is a complicated question. It seems to me that if you’re trying to keep your prejudices from affecting other people, you’re not so prejudiced as you think you are. Suppose you have the notion that people with blue eyes are shifty and untrustworthy. If you know that this is not true, and try not to take it into account when making decisions, you’re already making a reasonable effort in the right direction. On the other hand, if you believe that it is true, you really don’t want to prevent it from affecting your decisions, because it’s a valuable data point, at least in that worldview. It’s not a question of having the right but having the power—and whatever gives me the power to decide based on valid reasons also gives me the power to decide based on invalid reasons.