It all goes back to a trip I took through one of the haunted houses back in St. Louis. Not a "real" haunted house, but one of those walk-through jobs filled with all manner of creepiness, and the occasional angry actor. There were some truly chilling moments.
The one that stands out in memory ran like this ... you enter a room. It's a small theater - or perhaps a chapel. It's hard to tell because it's dark and dusty, filled with cobwebs. Before you step two feet into the space, you are aware of twenty or so people - or corpses - sitting in rows facing forward. All of them perfectly still. You know you must walk down the center aisle to exit this space and continue on through the maze. But it's so quiet, and so still ... and you are surrounded by bodies. The rational part of your mind knows that they're just mannequins and perhaps an actor or two. But one thing is for certain: at any moment one of them could reach out and grab you as you walk past them. You're frozen in place.
Well, at least I was. So were the people I went with. Looking back from the front of the theater/chapel (I eventually made it through the aisle of doom) I noticed the same reaction from the people behind us just entering the space.
Why? What made that so scary?
At other times during the haunted house experience, my party ran into actors who just kind of got in our faces and screamed. It was laughable. It was simple anger, and anger is not scary. Sure, it signals that whole "fight or flight thing" but you know where you stand. Your'e gonna have to turn tail or kick some tail.
What made the theater/chapel so scary is you don't know where you stand. It's a mystery. It allows your imagination to dredge up the worst possible scenarios for you to chew on as you tenderly step down the aisle. Think about it: when you've been the most frightened, the most scared it was the mystery of the whole thing. Not knowing turned on those dark thoughts you suppress in every day life. I'm not just talking about when you watched The Ring. I'm talking about your first trip to the dentist. Sleeping alone in the dark. Feeling sick, but not knowing what illness has infected your body.Sort of a corollary to this is when the everyday and ordinary person, place or thing is turned slightly askew. On some level you know it's not right, but you can't quite grasp what it is. This turns on the mystery but on more of a subconcious level. It's like when the folks who scare up that "generic" halloween music throw in lots of subsonics. It's there, you can feel it, but you can't quite hear it.
Creepiness works because it engages our imagination and our memories. It makes us do part of the work. Mere anger is easy to tune-out. Heck, raise your hand if you've ever successfully ignored an angry boss/parent/teacher.
(In the interest of encouraging better theater and, by extension better haunted houses, I strongly recommend The Empty Space by Peter Brook.)