The How and Why of Scary Movies

Since the earliest days of cinema, audiences have loved nothing more than a good scare. But with so many real fears in the world, why do so many people want more things to be afraid of, even if they're make-believe? And how do good directors manage to conjure this emotion so well?

To answer these questions, ABC News' Jay Schadler spoke to M. Night Shyamalan, director of The Sixth Sense and Signs, and Sigourney Weaver, who starred in 1979's sci-fi shocker Alien, one of the most frightening movies of all time.

Shyamalan makes movies that don't just go bump in the night — they haunt you after you leave the theatre.

"Most movies go for the pops — the big explosions," he said. "The movies that last for us are the ones that kind of do it the other way, kind of take the floor away from us and change expectations and make you uncomfortable and challenge us."

Part of Being Human

Scary movies allow the audience to think about other fears than their own, said Weaver, who stars in Shyamalan's latest film The Village, a supernatural thriller set in 19th century Pennsylvania.

"When we see someone keep it together in a situation of great stress and terror, it sort of, I think, excites us and makes us feel a little more capable. But it's also a great ride," Weaver said.

Scientists say fear plays an essential role in human survival by alerting us to danger.

During a creepy movie scene, a primitive part of our brain dedicated to fear called the amygdala wages a tug of war with our higher intellect — it allows thrill-seeking with a safety net.

Understanding fear is one thing. Generating it is another. Weaver said one of the things that made the creature in Alien so scary was its intelligence.

"I've always felt that the more intelligent you make the monster — the more knowing, the more perceptive — I suppose in a way the more human-like, the more frightening it is," she said.

You can also scare the actors. Weaver recounts that when she did the last scene in Alien, her character thought she had finally escaped in a shuttle.

The director, Ridley Scott, then asked her if she wanted to know what would happen, Weaver told him: "Absolutely not. Totally surprise me."

When the alien's arm suddenly flew out, clutching her ankle, she flew across the room in her underwear, she said. "If it really happens to you that way, it's a great [help] to the actor."

Techniques of Terror

But fright not only comes from in front of the camera, but behind it. Shyamalan revealed to Primetime a few of his tricks from previous movies:

He lets the camera drift, just the slightest bit. It "creates this sense of 'Something is going to happen,'" he said.

In Signs, Shyamalan lowered all the lights - "so that the shadows were very large."

He has also used no lights whatsoever. Also in Signs: a character is wandering in the fields when he loses his one piece of protection — his light. Shyamalan switched to a wide, distorted shot to get a sense of the character's phobia. And he has the character reach below the camera to give the audience a sense of how blind he is.

When the light snaps back on, the audience gets a glimpse of a creature's leg slipping between the cornstalks. Monsters are more frightening when they are given less camera time, Shyamalan believes.

In the art of terror, less is more, and often what you hear can be more unsettling than what you see.

Shyamalan says there is a scene in The Village that was so scary that it would have earned the entire film an R rating. He changed one piece of sound — of something that wasn't even happening on screen — and it made the film suitable for a PG-13 rating.

He wouldn't say what the sound was. When asked if it was the sound of bones crunching, he said only: "You're close."

Mundane to the Macabre

Shyamalan doesn't think he's a sick and twisted individual. "Actually, I'm very boring and normal," he said.

In fact, the most gifted directors find the heart of our fears in the intersection of the humdrum and horrible. That's exactly the mix of elements in Alfred Hitchcock's horror classic Psycho — and Weaver is a huge fan.

"I love it when directors tell stories about situations we've all been in," she said. "This woman is in a horrible driving rain storm. She finally sees a motel that is a little lit up. And thank God she gets there, and the guy is nice, and they have a meal, and what could go wrong? And then out of nowhere … "

In one of the most famous horror scenes of all time, an unseen attacker slashes repeatedly at the woman as she takes a shower.

This move from the mundane to the macabre also happens in Jaws, a Shyamalan favorite.

He describes a scene where beachgoers are relaxing on an ordinary summer Sunday and the sheriff, played by Roy Scheider, is scanning the water for signs of trouble.

One of the beachgoers is throwing a stick to his dog, calling out the dog's name, Pippen. There are screams — but they are from delighted children playing. A boy lifts his girlfriend out of the water on his shoulders.

"The audience starts to get paranoid about Roy and what he's thinking," Shyamalan said. "Suddenly you just cut to the beginning of the real stuff, which is the guy that you started with. He goes 'Pippen, Pippen' — and he can't find his dog, and that's it."

"Now we're going to get serious," Shyamalan says — because after all the red herrings, all the false alarm. and the built-up tension, the shark soon appears. "It's really just brilliant."

"I watched the scene and then I said 'I'm never going to make movies this good. It was perfect," he said.