The mind is a malleable instrument. It reprograms itself to handle changing circumstances all the time. Regular exposure to particular ways of thinking or actions reinforced by positive attitudes will foster a positive attitude toward that way of thinking or acting.
Huh?
Regular depictions of violence reinforced with pleasure (as in slasher movies) inevitably associates violence with pleasure. I’d postulate that Biblical violence portrayed in juxtaposition with the “Yay for the good guys!” attitude of any congregation of Chosen People helps make such atrocities more acceptable, should an occasion come up.

http://en.wikipedia.org/wiki/Milgram_experiment

“The subjects believed that for each wrong answer, the learner was receiving actual shocks. In reality, there were no shocks. After the confederate was separated from the subject, the confederate set up a tape recorder integrated with the electro-shock generator, which played pre-recorded sounds for each shock level. After a number of voltage level increases, the actor started to bang on the wall that separated him from the subject. After several times banging on the wall and complaining about his heart condition, the learner gave no further responses to questions and no further complaints.[1]

At this point, many people indicated their desire to stop the experiment and check on the learner. Some test subjects paused at 135 volts and began to question the purpose of the experiment. Most continued after being assured that they would not be held responsible. A few subjects began to laugh nervously or exhibit other signs of extreme stress once they heard the screams of pain coming from the learner.[1]

If at any time the subject indicated his desire to halt the experiment, he was given a succession of verbal prods by the experimenter, in this order:[1]

1. Please continue.
2. The experiment requires that you continue.
3. It is absolutely essential that you continue.
4. You have no other choice, you must go on.

If the subject still wished to stop after all four successive verbal prods, the experiment was halted. Otherwise, it was halted after the subject had given the maximum 450-volt shock three times in succession.”

The rules for psych experiments with human subjects have been changed so this type of experiment would not be allowed today. But it was replicated several times with similar results.

It’s also interesting that violent depictions of the crucifixion, execution of martyrs, passion plays, etc. are associated with religious violence. One would think that such graphic depictions of suffering of beloved saints would make people less likely to harm others, but not so apparently. I wonder how many people who went to see Mel Gibson’s Passion of the Christ made any parallel with Abu Ghraib for example