Is hatred a natural response to fear or is it taught?

I was reading some other posts to another question and the topic of hate came up. The more I thought about it I began to wonder what hatred really meant.
I think as difficult as it is to describe and understand love if you never felt it, it is equally hard to describe and understand hatred.
I started to think if there was ever anyone I hated. I have feared people, I have distrusted people and I have been angry at people. I have been loathed the action of many. People who misuse the weak and defenseless.
But I realize I can understand the extreme nature of love but since I do not understand brutal people, I can’t seem to hate them.
I’m no Ghandi, thats for sure but I’ve realized that I have used the word hate without ever really understand what it means to hate.
So back to my question. Is it taught or a response to fear?
Or do you think it comes from someplace else?
Is it just the absence of Love?