I went and saw a movie last weekend. It was about evil of a residential nature. I think the genre and the format (adding an extra D to the equation) had a lot to do with the previews that they decided to show. There was either horror, 3-D, or horror shot in 3-D. I'm not a die-hard horror fan, but I'm finding the reasons that people are interesting.
My father-in-law is currently a regular viewer of a newer fishing show that profiles an "extreme" fisherman that goes after river fish of the "OHMYGODITSMOBYDICK" variety. The last episode was on location in/on the Amazon river attempting to track down a catfish that can theoretically grow to a big enough size to eat a man whole. During the set-up, there was a lot of narrative supposition on the existence of such a creature. The funny thing was that each time the possibility of the man-eating fish came up, my F-I-L scoffed at the idea and repeated to himself how ludicrous and impossible it was.
Now, I suppose that your curious as to why I jumped from the topic of horror to the topic of fish (but, to be fair, it was the topic of a man-eating fish). Now I've had (past-tense for good reason) friends that loved the horror genre for the vicarious kicks. I have friends that love the genre for the story, the special effects part and parcel to the experience. And I have friends that love the genre because of the social, political, and economic statements that are allegorically woven into the piece. But I think that the good portion of horror fans love the genre because maybe it give them a safe outlet to control fear.
Now, as your average modern citizen, despite what the news screams at us on a nightly basis, we live pretty safe lives. We don't have to worry about huge cats jumping out of tall grasses as we look for tubers. We don't have to worry about unseen terrors bursting from a calm river as we gather water. We don't have to keep a roaring fire burning at the entrances to our homes to keep the unknown killers in the night from dragging us from its safety. But the fears that kept our ancestors safe for so many millennium are still lurking around in our DNA, prompting random reactions of terror from sources that aren't all that scary.
Watching a terrifying movie or reading a chilling story lets us fire that fear up without ever having to really worry about consequences (big cats, sharp teeth, and such). So, next time you're enjoying a good and scary flick, thank those jumpy ancestors of yours, and rest assured that everything is alright. At least until the zombie uprising. :)