The thirst for vengeance does not come from nowhere. It has a clearly identifiable cause. The thirst for vengeance has its origins in infancy, when children are forced to suffer in silence and put up with the cruelty inflicted on them in the name of upbringing. They learn how to torment others from their parents, and later from their teachers and superiors. It is nothing other than systematic instruction by example on how to destroy others. Yet many people believe that it has no evil consequences. As if a child were a container that can be emptied from time to time. But the human brain is not a container. The things we learn at an early stage stay with us in later life.
Alice Miller, The Origins of Torture In Endured Child Abuse