I wonder if any study has even been done on the genesis of hate? A song from South Pacific is "You have to be taught to hate". Do you?

I believe hatred is taught.   Children are born innocent.   When little children play together, they don't care about the color of their friends skin.  To them it's simply their friend.
Who teaches them to hate?  (introduces them to the position of hate) Other people (parents, teachers, relatives, TV/media, etc.); either by words or by example.  When this happens they lose that innocence ... forever.  Once a child has been poisoned by hate, they teach it to their friends (again, by words or example).  Suddenly their friend who has darker colored skin, or who acts differently, or who believes differently, becomes an enemy.