The source of hate is generally one’s family and/or the society at hand. But now a popular source of hate is the internet. People can learn hate by surfing and finding something that resonates with them. Something that fits their personality and their situation.
Either way, hate is a learned phenomenon. Then it needs a supportive environment in order to mature and advance into violence.
But ultimately, hate needs a receptive mind. It’s the parents who have the most influence over their child’s development. Hate will not develop where there is no room for it.
But it will develop nicely if the seeds have been planted in a child’s young and developing mind. Hate usually begins at home, founded on the attitudes and values of the parents.