"All my narcissistic patients have had the experience of being deeply humiliated in childhood by parents who used power as a means of control. In many cases, the power is physical force; the parents use their superior physical strength to force the child into submission. Spankings are a common form of such physical abuse and can be particularly humiliating if the child is forced to expose his or her backside to the blows... sometimes the humiliation is increased by making the child fetch the instrument of punishment or by threatening to increase the punishment if the child tries to escape. There are parents who intensify the beating if the child cries, as if to deny the child even the right to express hurt.... Of course physical punishment is not the only way to humiliate a child. Frequently children are criticised in a manner that makes them feel worthless, inadequate or stupid. Such criticism serves no useful purpose; it is intended, in my opinion, to prove the parents superiority. Some parents will laugh at or mock a child when the child makes a mistake or gives an answer that the parent thinks the child should know. When the child cries, the parents may dismiss the childs feelings as spurious, making some sarcastic comment about crocodile tears. The list of ways children can be put down, beaten, broken, and denied respect for their humanity and selfhood is long. And many parents think there is nothing wrong in this attitude.... one of the answers I would offer is that parents act out on their children the kind of treatment they receive from their parents... Parents who feel powerless in the world can compensate for this feeling by being dictatorial with their children."
Source - Alexander Lowen, Narcissism, Denial of the true Self