I think you have it backwards. People are born selfish, greedy, violent little terrors. They are taught that other people have rights. A group of 5-year olds will ostracize anyone who looks or acts different, they don't need to be taught to be bigots. Instead, they need to be taught to be accepting.
Now, teaching them bigotry doesn't help matters, but IMO, people are born terrible, and society is stuck fixing that.