In Michael Powell’s masterful Peeping Tom (not a horror film, but a wonderfully perceptive psychological thriller) the pathetic Mark Lewis is obsessed with the study of fear. He is a serial killer who forces his victims to watch their own deaths. “Do you know what is the most frightening thing in the world?” he asks. “It’s fear.” This may not be an objective truth but, like Mark, we in the audience viewing a horror film, in the comfort of the dark and the company of other watchers, enjoy seeing the fear of those about to be killed. And we like sharing our own fright: seeing a horror film with others in a darkened auditorium is much more exciting, and finally satisfying, than watching it alone in our living rooms. Why is that? And why do so many of us seek out these thrills in these sort of movies?

There have been many theories, psychological studies that try to define “horror” and explain our fascination with it. It is not, at first, logical that we should wish to be scared. Their observations are often interesting, but none is entirely convincing, either for the general public or psychiatrists, who spend their days considering the machinations of the human mind. It is true that we all share some basic primitive fears that are likely hard-wired through evolution. Fear of the dark, of what can’t be seen, fear of creatures with sharp teeth, or crawling things like snakes, rats or spiders, of thunder and lightning and, especially, the fear of death.

In his essay “Das Unheimliche,” Freud suggested that horror comes from the “uncanny.” This describes situations that touch our nightmares, things that seem almost ordinary, but not quite. The familiar altered just enough to be scary. Freud said that these sensations occur “either when infantile complexes which have been repressed are once more revived by some impression, or when primitive beliefs which have been surmounted seem once more to be confirmed.” Think of Frankenstein’s monster or, in a more recent trend, zombies: they seem human, even ordinary, except they walk with a strange lumbering gate (or in some films, unnervingly fast) arms outstretched, with dead eyes. And they eat human flesh. Just different enough to be “uncanny.” And of course, they want to kill. Ghosts are also uncanny, human-like but with no body.

A doll, a child, even a snowman with murderous intent are all “uncanny.” In the recent film, The Babadook, the monster becomes the mother (or the mother, the monster; either way it’s terrifying). The boy’s mother uncannily becomes an extension of the Babadook monster, someone the child becomes afraid of even as he turns to her for safety. As Roger Ebert memorably said about Alfred Hitchcock’s Psycho, tongue very much in cheek: “One fear we all have is of disappointing our mothers.” In Wes Craven’s A Nightmare on Elm Street, Freddy Kreuger uncannily lives in your nightmares and kills with his knife- like claws. The Babadook has an elongated body and similar knife-like fingers; he is quite scary on his own, but not nearly as scary as when he becomes the protagonist’s mother. This hiding of identity adds to the sense of the uncanny. So many of the monsters in slasher films (in which a killer stalks a series of victims, usually killing them with a sharp weapon—after Psycho, John Carpenter’s Halloween is the most famous example) wear masks—ordinary or grotesque, these masks hide the creature behind them, and are all the more frightening because of that.

In fact, the moment the antagonist is revealed is often the moment when scary movies can lose their power to frighten. Stephen King’s It is far scarier inhabiting the body of a homicidal clown, than in it’s true form as a spider. Part of this is the lure of the unknown, the undefined, Freud’s “uncanny.” To define, quite literally, means to set boundaries around, and thereby contain (something is defined both by what it is, and what it is not). It is scarier not to know what some threat is, than to see that threat. A killer wearing a hockey mask is scarier than a killer with no mask at all, because we wonder why and what: why it wears the mask and what it hides beneath it. The 1950’s film Them, where the monsters are giant ants mutated by radioactivity from atom bomb tests, is terrifying for it’s first half when we only see the victims reaction to first smelling something strange, and then seeing the creatures. Their screams are our screams. Once we actually see the giant ants, though the special effects are impressive, they seem much less frightening, and the film shifts genres and becomes an adventure thriller—scientists versus the monsters. It’s still absorbing---but it no longer scares us. The fine line that film-makers must walk is to reveal the bad guy without it feeling like a let-down. The other option, never to reveal the bad guy, can also feel like a let-down or like the film is somehow “cheating.”

The monsters in horror films can change with the anxieties of the era in which they are made. In the 1950s, with the Cold War and the threat of mutual annihilation by the hydrogen bomb, the monsters were the result of nuclear accidents (for instance, the giant ants in Them, one of the best films from that era, or The Creature From the Black Lagoon, one of the worst), or they reflected the terrors of the “organization man,” as people became concerned about the dangers of conformity (Invasion of the Body Snatchers). Body Snatchers also played on the uncanny—are these really the people in my life, because they seem not quite right…? In the 70s, when Baby Boomers’ children were entering adolescence and beginning to challenge their parents, the slasher films put teenagers in their place. Misbehave, stay out late at night, party with friends in the woods or, heaven forbid, have premarital sex, and you were surely doomed. And in the 2000s, with Ebola and other viral pandemic fears, zombies stumbled ravenously into our movie palaces.

When we are children, we are prone to nightmares. Our worlds are less clearly delineated between the real and fantasy. Children learn through play and pretending, and play encourages fantasy and imagination which children learn to separate from the real world they are just beginning to understand. Even as adults, it is sometimes hard to be sure something we dreamed so vividly didn’t really happen. This is part of ordinary development, but it’s not well understood neurologically. Some children even have night terrors—a form of nightmare that doesn’t want to “turn off” when you wake up. These are likewise not well understood, and they usually fade as we become adult. But the sense of the fantastic that is part of most dreams, and of many nightmares, remains with us, literally in those suffering night terrors and within the mind and memory of the rest of us. And this vein of fear that rests like sediment somewhere inside our minds is mined and tapped by the better horror films. Which is why we suspend disbelief at the impossible in these films—the creatures that fly, that jump out of dark corners, that change shape before our eyes. Such things did happen, we seem to recall. They just happened in our dreams.

One of the most terrifying images I can remember was seeing, as a child, the original Bela Lugosi film, Dracula. Dracula is a black-and-white classic from the 30s, very old-fashioned and rather corny now. But it defined Dracula for my generation. When Bela Lugosi first walks down the massive castle stairs, enveloped in a black cape, and declares, in that wonderful Mittel-European accent, “I am Count Dracula,” you knew you were in for it. But for me, the spookiest moment was a later glance out the castle window: we see the Count crawling down the outside face of the castle—head first. Talk about uncanny!

In horror films, we can relive these nightmares, knowing now that they are not real. Not just our logical certainty that they are fantastic and could never happen, but that they are not happening to us. We can experience a fright vicariously: it’s happening to someone else, and that someone is not real, a double buffer zone that insulates us enough to add pleasure to the sense of fear. To the extent that we identify with a character, we may fear for them, and experience the fear as our own, but at a sufficient distance. In fact, the better the film, and the more we identify with a character, the more intense our own fear, which is why smarter, more literary, character-driven horror movies tend to be better, more effective, and remain with us longer.

Then the film ends, the monster is vanquished-- and we are relieved. The lead character may live or die, but we are okay. We can reassure ourselves that it was all make-believe, exiting the theater into the neon-bright, popcorn-scented lobby, or turning on the lights in our living room and quickly switching the TV to Letterman. Meanwhile, we have had an adrenaline rush—an excitement that is lacking from our ordinary life.

At this point, it might be useful to distinguish between two types of horror, one of which might not, technically, be considered horror at all. Depending on your dictionary of choice (we checked Google and the Merriam-Webster), horror is defined as “an intense feeling of fear, shock, or disgust;” “a strong aversion or abhorrence;” an “overwhelming and painful feeling caused by something frightfully shocking, terrifying, or revolting.” Terror, on the other hand, is defined as “extreme fear;” “an instance or cause of intense fear or anxiety;” “a cause of anxiety.” Thus horror incorporates “shock,” “abhorrence” and “disgust” while terror is about “anxiety.” The realm of blood and gore, of revolting masks and costumes, of fear in anticipation of watching people in pain, is largely that of horror. Likewise, when something jumps out at you to the sudden shriek of violins in the soundtrack—that is the realm of horror. Terror is a cleaner, more cerebral form of fear, about provoking tension and anxiety, and its definition does not include shock and disgust. It is what we tend to term “psychological horror,” in which there is little or no focus on the death or attack or infliction of wounds, but rather on the tension leading up to it. There are wonderfully scary movies in which there is little or no blood at all (The Others, The Sixth Sense, The Haunting). There are likewise movies that are not particularly scary in terms of their structure—the fear is in anticipation of disgust, of what you know you will be obliged to watch in spite of your instincts to look away. Here, the viewer wants to see over-the-top blood and gore. Examples are cult favorites like Peter Jackson’s Braindead, or the Evil Dead series (occasionally with a dash of comedy to lighten the mood) to the bizarrely-popular “torture porn” trend of the early 2000s (the Saw and Hostel series).

In breaking down what film-makers do, in order to provoke fear in the audience, there are three major tools at their disposal:

1) The active showing of disgusting, gory, wince-inducing things, whether actions (i.e. zombies eating people’s heads) or images (i.e. people’s heads that have been partially eaten by zombies). Knowing that we are watching the sort of film that will not “cut away” as some violence befalls a victim provides a pull inside us—on the one hand, we have volunteered to watch this sort of film , but on the other, it is a human instinct to avoid seeing something unpleasant, so we find ourselves being pulled towards and away from the film, curious to see what will happen and forcing ourselves to sit through it, anticipating the revulsion, all of which can get the heart racing—which is the goal of any scary movie.

2) Shock is perhaps the easiest of ways to get your audience’s heart racing. A slow, quiet buildup of a character moving through an eerie space and then, BAM, something jumps out at her, assisted by a loud and sudden sounds. Shock is frankly so easy to pull off, from a film-maker’s standpoint, that it almost feels like cheating. But it works consistently, tapping into that evolutionary hard-wired wariness of the unseen dangers that might pounce at any time.

This corresponds to the earlier point about comparing what you would do in a situation to what the on-screen character does (would you really walk through that darkened corridor?) That something scary will jump out at the character also brings about precisely what we might fear, were we in the same situation. Walk around a darkened corridor in real life, and (hopefully) no axe-wielding maniacs will jump out at you, but we might feel nervous doing so nonetheless, because we do not know what is in the shadowy corners we cannot see. Awareness that we are watching a horror movie encourages us to believe that, in a slow build-up moment, something shocking will occur, and so our heart races in anticipation, usually assisted by the soundtrack, which mirrors and pulls along the increasing beat of our hearts. The most famous example of the power of sound is the shower scene in Psycho. The screeching violins and the dull thump of the knife entering poor Janet Leigh’s flesh add immeasurably to the horror of the moment. Try watching it with the sound turned off. The editing is brilliant---but suddenly it is much less shocking.

3) Toying with empathy allows viewers to put themselves in the shoes of the victims of violence in horror movies, both voyeuristic and also offering a relief that it is someone else, and not them, who is suffering (with the added double-buffer we have discussed, that we know that the person on-screen is an actor, and not really suffering—those who take pleasure in watching people really suffer are sociopathic, and fodder for a different article). Safe and comfortable in our pajamas in the living room, or in a theater full of people, we can watch violence with the safe assurance that it is not happening to us. But the film-makers will try to play with this, for empathy is an innate human quality, and lingering on suffering, particularly if we like the suffering character, encourages our sense of empathy. We fear for the character, and we can imagine how we might feel in a similar situation.

Terror movies, aka psychological horror movies, have more complex and subtle tools to hand. There can still be shocks, bad guys jumping out of the darkness, but the focus is on creeping dread, anticipation of violence or of seeing something you’d rather not see (or that you’re ambivalent about wanting to see), but cutting away before the revulsion component is brought into play. Viewers who know that they are watching terror and not horror can rest assured that they will not be obliged to watch the flying limbs and bloody mayhem.

This can make the films even more powerful, as our imagination fills out what the film does not show. But this requires more imaginative work on the part of the viewer. Horror movies can be more like blunt instruments or beach reads, a more passive form of entertainment in which the film does the heavy lifting for you. Terror movies demand active participation, thinking ahead of the characters at what might be, rather than just engaging with, and reacting to, what you see on the screen. Character development is key in terror films, because it’s important that we care about the characters, in order to care about their safety and hope they escape from danger. In horror films, victims are pieces of meat at the butcher’s (sometimes quite literally) and we might not want them to escape (at least not all of them), because seeing their demise is part of the fun. It is easier to watch an unpleasant or under-developed character being devoured by radioactive giant rats, than it is a carefully-developed protagonist with a wife and kids in whose safety we are invested. As a general rule filmmakers know that, and the more likeable and three-dimensional the character, the greater the likelihood that they will survive until the credits.

The literature of who enjoys horror, and why, is often confusing. The audience for graphic slasher films seems different from what we might call “terror movies” though, for the purposes of general understanding, the widely-accepted term “psychological horror” can remain. Tamborini, in the essay collection Horror Films 1996, argued that people who register high in empathy (the ability to put yourself in someone else’s shoes, emotionally) should not like horror films, because they are distressed to watch other people suffer. But this doesn’t seem to fit with common experience, and the correlation disappears when newsreels of violence and torture-based films were eliminated from the study. Hoffner and Levine (in an article in The Journal of Media Psychology, 2005, quoted in The Psychologist) did an analysis of 35 studies of people’s reactions to scary movies. They reported several relevant traits of those who enjoy horror: people who seek out intense experiences (so-called thrill-seekers, who might enjoy adrenaline sports, bungee jumping, etc.) and those who report a lower level of empathy, those who are more aggressive, and men (this group seems to prefer the gorier horror films). Much of the problem with these often-contradictory studies is that they are usually based on what people report, which is not always honest. For instance, are men more likely to say they enjoy horror films because to admit to not liking them makes them seem less manly?

Interest in horror films does seem to fade with age. The most enthusiastic are young teens, followed by young adults. Most of us older adults have outgrown them. Stuart Fischoff, et al, in The Journal of Media Psychology, points out that “Movie monsters provide us with the opportunity to see and learn strategies of coping with real-life monsters, should we run into them, despite all probabilities to the contrary…a sort of covert rehearsal for…who knows what.” This might explain the best-selling popularity of books like Max Brooks’ The Zombie Survival Guide. Fischoff describes two opposing threat-related coping styles: “Some like to approach or confront, others prefer to avoid or deny. The former are more positively excited by scary movies than the latter.” But as we grow older, our need to rehearse and relive our fears from childhood fades. We have had grown-up experiences that we rely on to replace them.

D. Zillman, in The Journal of Personality and Social Psychology, suggests that a sense of relief is the primary pleasure of watching a horror film. But that doesn’t seem right. The better horror films give moments of pleasure throughout, not just when they are over. Some of those pleasures are social. In the slasher films that followed Halloween and the first A Nightmare on Elm Street, there is an almost Victorian morality at work. The teenagers who have sex are guaranteed to be victims—they are getting what they “deserve” for behaving badly. Similarly, Mathias Clasen (a literature scholar at Aarhus University) notes that, in zombie monster films (and TV shows like The Walking Dead) “the zombies drastically reduce the moral complexity of life. They are unequivocally bad, they need to be killed…there is no moral shade of grey…” These films appeal to people who have little tolerance for ambiguity—it’s clear in these films who the bad guy is, and who deserves to die.

Horror films are remarkably popular for dating. A study by Zillman and colleagues in the 1980s, showed that teenage girls enjoy the films more when they are scared and their date is not—they can scream and be comforted. And the boy enjoys the film more when his date shows that she is frightened (this is nicely called the “Snuggle Theory.”) Traditional gender roles are confirmed—the boy will be brave and protect the girl. There also may be something of a tribal ritual about going to these films. If you can “survive” them, you have passed some societal test—you are showing mastery over your fears.

Brain studies show that when we are watching a horror film, the amygdala, the part of the brain that responds to fear and danger is, surprisingly, not the most stimulated. Instead, the thalamus and the prefrontal cortex go into overdrive—these are the parts of the brain associated with attention and problem solving. So what we actually may be doing when we watch these films is rehearsing how we might respond in such a dangerous situation—and comparing our response to what happens in the film. Would we really go into that dark room without a weapon to protect ourselves—and without putting on the light? It seems that we engage in an imagined training session for dangers that, thankfully, we are quite unlikely to find in our everyday life.

Though most of us will never have to worry about undead spider clowns (here’s looking at you, It), there is one danger we all face—the existential reality of death. The enemies who threaten death, and the potentially gruesome and creative ways in which victims die at the movies, may be thankfully distant from our reality, but death itself is all too close to home. Horror films allow us to contemplate this with a sense of distance and control. We see fantastic versions of our fears acted out by others, and we can play with our own responses and calibrate our own reactions. We can see how others respond (one reason it is more fun to see these films in a group), recognize that our fears are shared, that we are not alone. And we can enjoy the frisson of suspense and surprise, the delight in being alive in the moment, that the best of these films provides.

At least for some. Personally, I prefer comedies.

Dr James Charney is a psychiatrist and professor specializing in psychopathology in film. Dr Noah Charney, his son, is not a “real” doctor, but a professor of art history and best-selling author. Both from New Haven, they have also both taught at Yale, along with mother, Dr Diane Joy Charney. James Charney is teaching a three-day workshop at the Filozofska Fakulteta of University of Ljubljana called “Understanding Mental Illness” May 30-June 1, which is open to the public.