seems to indicate an interest in this topic that belies all the comments.
You ever see a train wreck? Or maybe just a big automobile wreck? It's impossible not to stare.
While we don't want to admit it, we have a bloodlust that must be satisfied somehow. We used to watch people fight to death in the colosseum, but in this (debatably) more enlightened age, we settle for watching violent movies and relatively bloodless, but still violent sports.
There is a sexual component to this as well. It is essentially the same principle, but it applies to something on the creation side. We all have a great desire to have our sensibilities offended, particularly when it comes to sex. This applies in varying degrees depending on a great number of factors, so different people will respond differently. Some people laugh, some, like us, make snide remarks, and on the far end, some people will exclaim "Well I never!" and hit the floor. It is worth noting that the other extreme is most decidedly aroused by this sort of offense. Guess who's buying her infamous video.
Just so everybody knows, I'm not making any sort of value judgement about anything. I'm the type to roll my eyes and switch the channel, but I do enjoy a good action flick when I find one.
Edited to add: I really need to lay off the psychology books for a week or two.
