The 10 Scariest Movies and Why They Creep You Out

You don't need anyone to explain why you should be afraid of a homicidal maniac with an ax, but that unease you get from the face with the rigid smile or from lookalike children? That creepy feeling has a theory that goes with it: It's called "The Uncanny Valley," and it helps explain why some of the most iconic horror movie characters spook us. (See below.)

In 1970, robotics professor Masahiro Mori created a graph charting people's comfort levels with robots, starting with the most simplistic machines and ending with the most human-seeming robots. He found that when the robot had human characteristics, but was still clearly a robot, people felt fine about it. They might have even thought it was cute.

But the huge dip in comfort – the graph's "valley," where people described unease and even revulsion – began when robots had enough human features that they seemed like creepy, defective people. Mori dubbed this revulsion the "Uncanny Valley" (riffing off of Ernst Jentsch and Sigmund Freud's theory of das unheimliche: "the uncanny," or the fear of the unfamiliar Other). Since Mori coined the term, the Uncanny Valley has become a term used not only in robotics, but 3-D animation, plastic surgery, and cinema studies.

"The concept of 'the uncanny,' or encountering an eerie double of oneself or of the human form, has been really important to many analyses of the psychology of horror," says Catherine Zimmer, associate professor of film and screen studies at Pace University in New York City. "A horror movie 'monster' represents the repressed elements of an average human being, and this is why they are unsettling. There has to be enough that is identifiable or relatable about a monster to make it truly disturbing."

Stephanie Lay, a Ph.D. student who researches the Uncanny Valley in the psychology department at the Open University, calls the scary figure a "near-human agent." She believes it becomes truly terrifying when we notice that it is too different from us. "Creepy dolls, badly animated CG characters, and slow-to-react androids," creep us out, she says, because "they dwell at the boundary between an object and a person."

The makers of Polar Express (2004) learned to their dismay that when it comes to making characters look incredibly lifelike, just because you can doesn't mean you should. They used a live-action performance-capture technique to animate most of the human characters, which gave them an eerie lifelike appearance critics described as creepy and zombie-like. Canadian film critic Geoff Pevere said of the Polar Express, "If I were a child, I'd have nightmares. Come to think of it, I did anyway."

Here are 10 iconic denizens of Uncanny Valley:

Before The Omen (1976) and Rosemary's Baby (1968) proved that children could be more horrifying than any old monster, Village of the Damned(1960) creeped out audiences with its white-blond, glowing-eyed children. These spawn of Midwich, England, all mysteriously born on the same day, have the supernatural abilities of mind control and telekinesis, and with their striking looks and odd affect they reside in that uncomfortable zone of the Uncanny Valley.

In George A. Romero's proto-zombie flick Night of the Living Dead (1968), Barbra and her brother Johnny drive to a cemetery where their father is buried, only to discover that it has been overrun by murderous animated corpses out for blood. This zombie is the archetypal Uncanny Valley figure: It looks human but drags itself around like a corpse, and it has an insatiable appetite for human flesh. And did we mention that it's dead?

At the beginning of Nicolas Roeg's Don't Look Now (1973), two sisters, one of whom is blind and clairvoyant, warn a couple (Donald Sutherland and Julie Christie) mourning their recently departed daughter that the husband needs to leave Venice before something bad happens. Based on a spooky short story by Daphne du Maurier, Don't Look Now is filled with tropes of the uncanny – doubles, ghosts, a crumbling medieval city. The film enters the Uncanny Valley with the appearance of a little girl in red that Sutherland's character finally catches up with....

William Friedkin's The Exorcist (1973) created a mini-hysteria when it was released. Not only were people fainting in theaters during screenings, but priests were outside to warn those queuing up. In the film, Regan (Linda Blair), a 12-year-old girl in the throes of demonic possession, takes us on a trip to the Uncanny Valley when she does some decidedly unhuman things like spinning her head and speaking to a priest in his dead mother's voice. Most terrifyingly, in a moment seen only in the director's cut, she walks down the stairs backwards on all fours, like a spider, while darting her freakishly long tongue in and out of her mouth like a lizard.

In John Carpenter's classic slasher film Halloween(1978), Michael has spent the last 15 years in an insane asylum for stabbing his sister to death when he was 6 years old. One day before Halloween, he escapes, returns to his hometown, and he becomes fixated on a local teen (Jamie Lee Curtis). For the remainder of the film, he pursues her in a blank, white mask. The impassive face of Michael's white mask, and his psychopathic determination to stalk and kill makes him a creature from the Uncanny Valley.

In David Cronenberg's 1979 film The Brood, something is radically off about a group of mysterious children in red coats who suddenly appear and begin attacking people. Dr. Hal Raglan (Art Hindle) is a divorced man who launches an investigation into a controversial therapy technique his ex is participating in after their child comes back from a visit with mysterious bruises and scratches. As he gets closer to the secret of the demon children who harmed his daughter, the dwarf-like creatures proliferate, becoming angrier and even more murderous. It's when we finally see their faces that their special place in the Uncanny Valley manifests itself in all its horrible glory.

Forty-one-year-old Corky (Anthony Hopkins) is a magician whose ventriloquist dummy, Fats, is taking over his act — and his life — in Magic (1978). Used at first as a prop to help him overcome stage fright, Fats's increasingly disturbing autonomy turns into domination. The too-human-like dummy with the New York-accent, blank expression and homicidal rage comes straight out of the Uncanny Valley.

David Lynch has his own truck stop in Uncanny Valley. In films like Blue Velvet Lynch finds the strangest shadows in idyllic suburban America, revealing its perversions and its violence. He makes the familiar strange and menacing—the definition of the uncanny—and brings to light that which was repressed. Lost Highway (1997) is a tale of doubles, switched identities, and confounding narrative absurdities. In the film's most famous scene, Bill Pullman's character meets a strange-looking man wearing white face makeup and blackened eyes (Robert Blake) at an L.A. party. "We've met before, at your house, don't you remember?" says the stranger. "As a matter of fact, I'm there right now. Call me." He does, and he is… "That's crazy, man," says Pullman.

A mysterious videotape begins circulating that causes its viewers to die within a week of watching it in Hideo Nakata's Japanese horror flick, Ringu (1998). We learn that in the video, a young girl with long hair obscuring her face has a terrible secret. Her creepy, zombie-like gait and monstrous, lethal appearance place her in the bottom of a well deep in the Uncanny Valley. (The Ring was the English-language remake in 2002 starring Naomi Watts.)

Pan's Labyrinth (2006), Guillermo del Toro's fairytale fantasy set during the Spanish Civil War, a little girl named Ofelia meets a magical faun who invites her to join his underground kingdom, on the condition that she complete three dangerous tasks. In one undertaking, she is to enter the banquet hall of the Pale Man to retrieve a gold dagger. The eyeless Pale Man sits motionless at a table, his eyeballs before him on a plate. When Ofelia disobeys the faun's instructions not to eat anything, he comes to life. First, his hands, red at their claw-like tips, creak into movement. Slowly, he places each eyeball into empty sockets on the palms of his hands, which he holds up to his face where his eyes would be in order to see. He staggers out of his seat and begins to pursue her...