Why We Crave Horror Movies

Yes I do agree in Stephen King's premise that we are all insane, somewhat. I agree with him in that he is telling the reader that we do have a weird lust for "sick" or "anti-civilization" things, that need to be released from within us, an example watching horror films. We like seeing nasty things in horror movies, we like being scared, we like seeing gore, we like seeing people get killed and what not on film. And I agree with King that this behavior does seem insane, but the truth is, that desire for gore and violence is within us. And I would think so especially since we are so civilized, the violent instinct within us (due to evolution and survival of the fittest) is dumbed down and never comes out.