I'm not a gore-hound.
To those of you who know me, that may come as something of a surprise. After all, I make dead people, and I have a lot of various body parts hanging around.
But there is a method to my madness. To me, there is something of a recipie for horror, and it deals with mood, suspense, and isolation.
The mood of a movie is a bit difficult to define, but I'll try and set it forth as the overall atmosphere and environment in which the story takes place. It's affected by a number of things such as art design, lighting and cinematography, and music and sound.
Suspense is created as an artifact of the storytelling. Hitchcock is a master of this, and pretty much created the theses of creating good suspense by letting the audience in on the secret of which the chatracters are oblivious. Certainly it's not the only way of creating suspense, but it is a good one.
Isolation is a tool. It's also probably the single biggest determinant of whether a movie is a horror movie, at least for me. Think about it: every single horror movie works around isolation as being a key element: you can't get help.
SPEED is a great example: suspense, but not horror. No isolation.
UNDERWORLD, not horror. No real suspense, very little isolation.
There are other elements, certainly. You have to actually care about the characters to have enough emotional investment in them, or the suspense doesn't work. That's not inimical to horror; it's something that's necessary in any storytelling genre.
The Sixth Sense is a wondefully moody pic. (If you haven't seen the movie yet, STOP READING NOW.) Look at the hidden isolation of Bruce Willis's character. You never really see him interact with anyone other than the kid, except for the anniversary dinner with his wife, which is a brilliant bit IMHO. It's the suspense element that has me wobbly as to whether it's a horror movie. There are elements of suspense, mostly having to do with the ghosts that pop up at unexpected times, but those are mood-scares more than anything. There's not a lot of suspense about the main storyline of the film.
Panic Room. Suspense. Mood. Isolation. Yet I back away from considering this a horror film. Why? Because the monsters were human? Consider what this movie would have been like if it had been space aliens invading instead of robbers. Would it have been a horror movie then?
Hmm... is there the necessity of a sense of inhumanity to the "monster" in a horror film? That would cover things like zombie movies and monster movies like The Thing and even Friday the 13th and Nightmare on Elm Street, but what about something like The Andromeda Strain? Does the "monster" have to have some active sense of malevolence?
Solaris. Horror, at least to me. Not so malevolent.
Dark City, not horror. Malevolent.
Movies like the Texas Chainsaw Massacre and The Hills Have Eyes aren't really horror to me, or they are a sub-genre that doesn't interest me all that much. Sure, I like the effects: it's my thing. But neither one of them is a satisfying experience as a movie to me. Human monsters just don't have the unknown factor to them.
Ooooh, there's a bit of insight. A sense of mystery about the "monster".
Eh. Doesn't fit everything, does it?