What are the main causes of racial prejudice?

I think that a lot of times prejudice results from a lack of understanding and knowledge about a culture or race. If one has had no contact or exposure to specific people in a race, they might be easily influenced by the negative remarks and opinions of others around them, including family, friends, and the media. A lot of children grow up in homes learning to be prejudiced against others by the examples of their parents. I respect people and parents who teach their children to form their own opinions about people on an individual basis.

It's lack of knowledge and it's usually passed down in families (i.e. people who are racist learnt it from their parents' behaviour). And it can only be combatted by teaching and peer pressure, though it's hard for schools to overcome what is taught in the home. Some of it is inferiority complexes too. People who feel bad and make themselves feel better by looking down on or picking on another group.

I believe to some extent it is lack of knowledge and understanding. But I also think it has a lot to do with how people were raised. Personally it irks me that some people hate others simply because of the color of their skin or because of their nationality. People have to give me a reason to dislike them, and it's never because of something they have no control over. If someone said they hated people with blue eyes, the majority of us would think that is a foolish reason to hate people, unfortunately they don't think how foolish their reason is for hating a different race.