Sympathy for the devil: identification with the aggressor
Dr. Sanity has a post that's well worth reading, on the topic of identification with the aggressor--how it begins as a normal process in childhood, enabling a child to manage threats and anxiety, and how it sometimes morphs into the pathological. She links this latter point to what's known as "Stockholm Syndrome," the identification with a kidnapper or hostage-taker by the hostage him/herself.
One of the worst feelings on earth is that of being a vulnerable victim. Humans will go quite far to avoid such a feeling--including, at times, deciding the aggressor is not so bad, after all; maybe even good. Of course, brainwashing can play a role in that transformation, especially if the kidnapping has gone on for a long time. But sometimes it doesn't take all that much, and overt brainwashing is not a necessary part of the process.
Abused children are among the most vulnerable of humans. Way too early in life, they are faced with the terrible dilemma of dealing with their own powerlessness in the face of an aggressor, sometimes even a family member whose proper role should be to protect. It's a fact that, although most abused children do not go on to becoming abusive adults, most abusive adults were abused as children.
I'm not offering this as any sort of excuse for such behavior--unfortunately, I'm not sure it's even an explanation. For we cannot ignore the fact that the majority of the abused do not take identification with the aggressor to the point where they become one. Au contraire.
So, how can we really explain the difference between those who end up becoming what, in childhood, they most hated, and those who go on to become exemplary citizens and parents? Those who identify with the aggressor, and those who don't? At this point, we really can't. It's one of the most important unsolved riddles in the social sciences.
It seems to me that there are two responses for a victim of childhood abuse. The first is to say "Never again." This child grows up knowing that this is one thing he/she will never do, and perhaps even later joins a profession or group that is involved in preventing, treating, studying, or fighting abuse. The second reaction is to let feelings be the guide. In a certain percentage of people who seem to lack operating moral brakes and who have identified with the aggressor, those feelings lead to a re-enactment of the crime, this time as powerful perpetrator. And thus the torch is passed.
[ADDENDUM: Just to clarify: abused children who grow up to abuse others do not necessarily norm their own abuse and think it was OK.
There are those who do, of course. For example, there are abusing parents who justify their actions in abusing the child by saying they are just "teaching my child about his/her sexuality," or who offer any number of other twisted but benign reframings, and who say they were not harmed by themselves being abused as children.
However, there are those who hate what the abusive adult did to them when they were a child, and yet they still grow up to abuse children. This is done by some mental mechanism as yet poorly understood, but the best description I can offer is that they are on emotional automatic pilot when they are doing the abusing. The feelings of rage and powerlessness are all there, encapsulated inside the adult, unprocessed and poorly understood. Those feelings now drive the behavior of the abusive adult, who converts the feelings of powerlessness felt as a child into a feeling of power over another child.
The worm turns--the victim becomes powerful by being the vicimizer. But the adult usually does not understand or have any awareness of the process by which this happens.]