Have you ever seen the movie, "Braveheart?" The method of execution which was partially depicted at the end was the penalty for high treason in England for many centuries. (Back when public schools actually taught history, people understood why John Hancock's big fancy signature on the Declaration of Independence was an act of bravery.)
Those executions were not done behind closed doors, they were done publicly and people came and watched. I can't even wrap my mind around the idea that people would go out of their way to watch a human being hung by the neck until almost dead, taken down, disembowled while still alive, with the body subsequently decapitated and quartered and the parts displayed at various densely populated locations.
Both collectively and individually, the society and the individual members who thought this type of thing was "normal" and "just" were far, far more hardened to violence and human suffering then we are today. We don't think it's normal to drive a stake through the heart of a suicide victim today. We don't pluck the fingers from a recalcitrant criminal's hand one by one with red-hot pincers today. When a man is guilty of high crimes today, we don't remove his genitals first and burn them before his eyes prior to the execution. We don't test the innocence of the accused today by giving them a red hot piece of iron to hold or by sticking their hand in boiling water. The punishment for poisoning somebody today is not boiling the guilty party alive.
We have moved so far in the opposite direction that the accurate presentation of historical events is more the exception than the rule. The very beginning of the movie "V for Vendetta" (Which is considered fairly violent) is a good example. The real Guy Fawkes only escaped the fate of William Wallace by taking a running jump off the gallows as soon as the rope was around his neck. His body was quartered anyway, but at least he was dead first. So the idea that violence in entertainment represents a recent trend of degeneration in human civilization is lacking in historical perspective at best.
The question of whether exposure to fictional violence makes people more comfortable with the real thing (Which is a separate issue) is a legitimate one. When it comes to violent video games, I'm ready to be convinced if there is credible evidence of increased aggression and violence associated with them. This is a hot topic in psychology right now. So far, that evidence has not been forthcoming and some studies (Kierkegaard et al) actually suggest the opposite.
