Hate spreads easier than anger
Hate can spread from one generation to another much easier than anger or frustration. For example, when we asked people who had experienced a war themselves and people who had only heard about it from others’ stories, the amount of reported hate was the same for both groups. This means that not only can people hate others based on someone else’s experiences, but that hate can be as intense as if they had experienced the event themselves. This was not the case with anger, which tends to be more intense if you experience the anger-causing event firsthand.
Physiology of hate
Unlike anger, there is no physiological pattern that is characteristic of hate, because hate is a long-term experience. Someone can do something to make you immediately angry, but usually, you need more information to hate someone. In the heat of the moment, however, the arousal patterns of hate in the brain and the body may be similar to anger.
There is a lot of confusion about hate and what it really means. If people realize that hate is something much bigger, that it includes the desire to eliminate others, maybe they will change the way they use the word. It takes emotional intelligence to discern between feelings. But it is something that can be developed. Perhaps making people understand what they are actually thinking and feeling, and why, when they say “I hate you,” or disentangling the different ingredients of their negative emotions, might be helpful. For example, you could say, “I know you are saying I hate you, which means that there is nothing positive that you can detect about this person or group, nothing that you have in common. Is this really true?”
I think it’s better not to let your emotions reach the level of hate, and to start working on them while you are still angry. If it doesn’t work, consider whether you still want that relationship.
Hate can dissolve over time if the hated individual/group leaves your life, changes completely, or if you can work on changing the way you think about them. But don’t count on it happening from one day to another. One needs to work on the disappearance of hate, like one has to work on maintaining love.