Slate has relationships with various online retailers. If you buy something through our links, Slate may earn an affiliate commission. We update links when possible, but note that deals can expire and all prices are subject to change. All prices were up to date at the time of publication.
From A Very Nervous Person’s Guide to Horror Movies by Mathias Clasen. Copyright © 2021 by Mathias Clasen and published by Oxford University Press. All rights reserved.
People who do not watch horror films often point to the “jump scare” as the main reason for their avoidance of such films. By jump scare, I mean the massive shock effect that often provides the climax for dread-drenched horror scenes. You know, the monster popping out of the closet or the ghost making a screaming entrance. And I get it, I do. Jump scares can be intensely unpleasant, and it is almost impossible to shield oneself against them. The jump scare is a cinematic grenade that the horror film lobs right into the nexus of your central nervous system. Sometimes it goes off before you even know what hit you. Other times it lies there for several seconds before exploding, and all you can do is stare at it anxiously, waiting for it to blow. Jump scares have a bad reputation, probably because they seem too primitive and easy to pull off, but they can be quite artful. And the biology and psychology behind the jump scare are fascinating.
Let me give an example of a particularly effective jump scare. This is one that had me literally jumping in the seat and gasping for breath. So I am watching the Netflix show The Haunting of Hill House with my family. The show, which is an adaptation of Shirley Jackson’s classic horror novel, is about a haunted and dysfunctional family consisting of dad, mom (now dead), and five children: Steven, Nell, Luke, Theo, and Shirley. The show crosscuts between their childhood and adulthood. Grown-up Nell killed herself and is now haunting the others.
We are about half an hour into the episode—a particularly creepy one that has all of us on edge. Theo and Shirley are in a car, on their way to Hill House because they suspect Luke of being headed back to their dangerously haunted childhood home. The estranged sisters are engaged in a heated argument, filmed from within the dark car. Only their pale, emotional faces stand out on the screen—Theo to the left and Shirley to the right. There is darkness between them. The only sound, apart from their shouting match, is the faint noise of the car in the background. Suddenly, a face bursts from the darkness between the sisters and shoots toward the windshield. The movement is unnaturally swift. It is dead Nell, screaming violently and eerily, pale, with dead white eyes and black veins standing out in her cheeks and a wide-open mouth exposing rotted teeth. The two living sisters are shocked and drive off the road.
When dead Nell burst into the dark space between the two sisters, my whole family jumped. I had been deeply engrossed in the episode, but now it was like my entire being resonated with that horrifying moment. My body galvanized itself with a real jolt, like an electrical shock, that seemed to radiate from my center to the extremities, producing a brief but intense pain in my hands and feet. The sensation was slightly unreal, like a momentary rupture in the fabric of things. I mean, I have been exposed to hundreds, if not thousands, of jump scares, but this one really caught me off guard and had me panting afterward, like I had been in a brush with death. But I also could not help but appreciate the artistry, the sheer craftsmanship, of a scene—a particular arrangement of visual and auditory stimuli emanating from a gadget in my living room—that had such an astounding effect. So, how and why does the horror film jump scare work? And is there anything you can do to avoid being knocked out of your skin by it?
The jump scare, which is also called the “film startle” and the “cinematic shock,” has a long history in the film medium and beyond. A jump scare occurs when a sudden and intense stimulus produces a so-called startle response. The precursor of the horror film jump scare can be found in the kind of playful behavior where somebody jumps up behind somebody else and yells “BOO!” (When scientists with an interest in the startle response scare the crap out of test subjects in the lab, they call it “administering a startle probe,” which, despite the clinical neutrality, has a kind of sly, sadistic ring to it.) Such behavior, playfully startling others, probably goes back thousands of years, as a favorite pastime for our evolutionary ancestors—and as a crucial element in suspenseful oral storytelling.
The film scholar and jump scare expert Robert Baird notes that we can trace the cinematic jump scare back to the earliest days of film, for example with such allegedly startling cinematic experiences as the Lumière brothers’ 1895 depiction of a train moving toward the audience. But Baird points to Val Lewton, the producer of the 1942 film Cat People, as the one who “formalized, even institutionalized, the startle for horror and thriller film.”
Cat People is about a Serbian woman, Irena Dubrovna, who claims that she transforms into a panther when she is in the throes of passion. She is in a relationship with one Oliver Reed, who is skeptical of her claim. He tells his assistant, Alice, about it. Irena finds out that Alice has a crush on Oliver and follows her home from a distance. In this famous scene, Alice is nervously running away from her unseen stalker. She reaches a bus stop. Suddenly, a loud hissing noise tears through the soundscape. As it turns out, the noise comes from an arriving bus, not a homicidal were-panther. Alice boards the bus to safety. This particular jump scare became known as a “bus”—a scene of dread that concludes with a startle that turns out to have been a false alarm.
The basic structure of a cinematic jump scare, according to Robert Baird, includes a character, an implied off-screen threat, and a “disturbing intrusion into the character’s immediate space.” That is how it usually works, but there are variations—such as my example from The Haunting of Hill House. Here the audience is completely unprepared for Nell’s intrusion. It is an incredibly tense scene because of the argument between the two characters and the sense that very bad things can happen at any moment, but the show has given us no reason to believe that the ghost is in the car. So that particular off-screen threat is not even implied. Typically, though, a dread-drenched scene leads up to an intense jump scare. The jump scare does not just come out of the blue. That is because the startle response can be primed like the carburetor in a lawnmower. If people are anxious, they respond to sudden stimuli with greater startle than if they are calm, because they already have anxiety juice in their mental carburetor. And psychologists have shown that if you startle people who are looking at pictures of “mutilated bodies or spiders,” they will startle more violently than if they are looking at pictures of “smiling children or nudes of the opposite sex.” The same principle is at work when a dreadful movie scene leads up to a startling climax. You are putting viewers in a jumpy state of mind to provoke an even stronger startle.
Sound is crucial to the jump scare. It is responsible for the better part of the startle, and it is almost impossible to counteract. An auditory stimulus can be processed faster than a visual one, and it takes more time to disrupt an auditory stimulus than it takes to disrupt a visual one. You can close your eyes or look away from a nasty image. You cannot close your ears or listen away. Sound plays a crucial role in both parts of a scene that end with a jump scare—in both the buildup and the climax. In the buildup, the horror film uses sound, or the absence of sound, to establish an atmosphere of dread or apprehension. If there is sound in the buildup, it is often nondiegetic, which means that the sound is external to the filmic universe. The characters cannot hear it. That kind of sound can be mood music, such as the famous duh-dun motif of Jaws. It tells you that danger is approaching; it is basically a cue for you to get anxious. The sound can also be—and often is—acousmatic, which means that you hear the sound but you do not see what is causing it, which can be tremendously anxiety-provoking because it taps into a fear of the unknown.
Sometimes, however, a horror film will use silence to build up to the jump scare. Silence can be intensely unsettling in a horror film, and avid horror film watchers will know that silence is almost never good news. The absence of sound foreshadows something horrible. It is as if the horror movie is holding its breath. The horror fans know this, on a gut level, and their system goes into vigilance mode. Also, the sheer difference in signal strength between silence and startling sound actually works to increase the effect of the stimulus.
The sonic buildup—whether consisting of unsettling mood music, silence, or sound effects—climaxes in an acoustic startle effect, also known as a “sound bump” or an “acoustic blast.” It is usually very loud diegetic sound, often mixed with equally loud nondiegetic sound—a scream, for instance, mixed with a boom or a so-called stinger (a sudden high-pitched sound). Consider the screaming violins that blend with Marion Crane’s death screams in the infamous shower scene in Hitchcock’s Psycho. Such sounds—screams, roars—target an ancient defensive mechanism in a fear system that humans share with many other species, and they are incredibly effective in eliciting a powerful startle. They are like echoes from a distant past when a scream or a roar might mean immediate and mortal threat to our evolutionary ancestors. Such sounds certainly worked well in the scene from The Haunting of Hill House, where Nell’s scream blends with a low-pitched booming noise, possibly a roar, and what sounds like several other screams in a cacophony of horror.
The jump scare usually has a visual as well as an auditory element—something nasty that suddenly enters the frame. It is the sound that really makes viewers jump, but it is the visual element that tends to stick with them. You do not really remember the sound of a jump scare, but the imagery has the power to burn itself into your memory. The brain processes sound and images differently, and images are more easily remembered than sounds. Typically, the visual part of the jump scare is a monster or a killer or something really disgusting suddenly entering the frame. Consider one of film history’s most famous jump scares—the scene in Jaws where shark specialist Matt Hooper is scuba-diving, examining the wreck of a sunken boat with a bulky underwater flashlight. He is investigating a big hole in the hull of the boat and discovers a huge shark tooth lodged in the ragged edge of the hole. Eerie music is playing in the background. Suddenly, a severed, bloated head floats out of the hole, accompanied by a stinger and a scream. That bloated head, with pale wormlike creatures squirming in an otherwise empty eye socket, is not something you forget straightaway. It elicits a combination of disgust and fear in viewers: disgust because it is clearly decomposing, and our species has an evolved aversion toward decomposing flesh, especially when it is human flesh, and fear because it suggests predation. We realize that this is the work of the shark, and the shark could be nearby.
This whole sequence expertly uses the affordances of the film medium to manipulate us, from low-level physiological stimulation to more sophisticated cognitive and emotional manipulation. Don’t let anybody tell you that a horror movie jump scare is stupid and easy. It can be, yes, but it can also be a surprisingly complex artistic device and a crucial element in a film designed to disturb and unsettle you. The startle response may look like a pretty primitive reflex, the operation of which can be reduced to a simple formula: BOO → AAAH! But it is actually a quite sophisticated, context-sensitive adaptation that has kept organisms alive for millions of years, and it can be exploited in artful ways by horror films.
The jump scare produces a so-called startle response, and the startle response is hardwired into human nature. It is so biologically fundamental that we share it with many other species. Indeed, startle is “universal in mammals, reptiles, birds, and amphibians,” according to the anthropologist and startle expert Ronald C. Simons. It is an “invariant response” to a “sudden, intense stimulus.” That stimulus can be visual, auditory, or tactile. It can be something that suddenly pops up in your visual field, a sudden noise, or something touching the back of your neck when you thought you were alone in a dark basement. The startle response evolved to protect us from sudden danger, and it works by rapidly galvanizing the organism in the face of threat. The startle process was described by two scientists, Landis and Hunt, in a classical study from 1932, as involving blinking of the eyes, head movement forward, a characteristic facial expression, raising and drawing forward of the shoulders, abduction of the upper arms, bending of the elbows, pronation of the lower arms, flexion of the fingers, forward movement of the trunk, contraction of the abdomen, and bending of the knees.
The purpose of the whole sequence, which typically takes about a second or less, is to protect vital organs and make the organism ready for confrontation with a threat. The eye-blink, which occurs as swiftly as 30–50 milliseconds after the startling stimulus, protects the eyes from trauma. It is followed by a widening of the eyes, which enlarges the visual field to allow for better threat assessment. The eyebrows shoot up to help open the eyes faster and wider. The mouth opens in a surprised O, probably to allow for a rapid intake of breath in anticipation of exertion. There is an almost-instantaneous up-regulation of the sympathetic nervous system, which is the branch of our autonomic nervous system that is responsible for the fight-or-flight response. Adrenaline and noradrenaline are released into the bloodstream, increasing heart rate and sweat secretion. The startle response is, in essence, an adaptive mechanism that prepares your system for action and tells you: Heads the fuck up! (Apologies for the vulgarity, but it only seems appropriate: Scientists have shown that startled people frequently resort to inappropriate language, such as “coprolalia”—dung talk—or terms that refer to “sexual anatomy or activity.”)
It is very easy to elicit a startle in others because the mechanism is on a hair trigger, and for good evolutionary reasons. It is like the emotion of fear, which also tends to overshoot—simply because a false positive (jumping at shadows) is better than a false negative (shrugging at a cue that turns out to be lethal). Also, the startle response is cognitively impenetrable. You cannot switch it off, and there is little you can do to attenuate the response even if you know a startle is coming. Anybody who has fired a big gun knows this is true. And anybody who has seen the same horror film twice and jumped at the same scare knows it too.
The startle response provoked by the jump scare can be unpleasant. The rapid and massive activation of skeletal muscles can even be a little painful, like receiving a mild electrical shock. People differ in the degree to which they startle. Some people are “hyperstartlers,” some are exceedingly difficult to startle, and most people are somewhere in between those extremes. People also differ in the degree to which they enjoy intense physiological arousal. So-called thrill seekers tend to enjoy it. But if you are not a thrill seeker and not a big fan of being startled by a jump scare, what can you do?
It is difficult to avoid jump scares without also avoiding horror films, but there are horror films with no jump scares. The Blair Witch Project is one. Apparently, though, the jump scare is more frequent in horror films than it used to be. Baird chalks it down to “the hypersensationalization of the post-Psycho horror/thriller film.” Whatever the reason, the website wheresthejump.com delivers statistics on jump scare frequency in about 250 movies. A typical present-day horror film has an average of 10 jump scares. Compare that with a horror film from the 1960s, which had only, on average, 2.6 jump scares. That number increased to 5.6 in the 1970s and then almost doubled in the 1980s, with an average of 9.5 jump scares per horror film (probably because of the prevalence of startle-happy slasher films in that decade). The number dropped in the 1990s but seems now to be settling at an average of 10 per film. Perhaps that is a natural optimum for the frequency of jump scares per horror film—a frequency that optimally stimulates viewers’ fear systems and startle responses without exhausting them. Too many startles can lead to habituation (they lose their potency), whereas just enough startles can lead to sensitization—one startle primes you for the next startle, which is felt more strongly and which primes you for the next startle, and so on.
If you cannot easily avoid jump scares without also avoiding horror films, you can try to reduce the effect of the startle. Do not watch a horror film if you are very tired, because your fear system is more responsive when you are sleep-deprived, and your startle response is likely to be more active than otherwise. Same if you are feeling anxious or jumpy. It is also more difficult to regulate your emotions when you are worn out. So look inside yourself before watching a horror film, and ask yourself if you might be better off postponing it. Also, there is some evidence that the startle response can be muted with the aid of, ah, chemistry, but I don’t recommend that. Alcohol, however, is known to reduce the magnitude of startle, so you might consider having a beer or a glass of wine before the film.
Additionally, if it is the jump scare that you are really nervous about, do not watch horror films in the cinema. Modern movie theaters are designed for maximum immersion and minimal distraction. They have awesome sound systems, and we have seen how important sound is to the jump scare. Moreover, a movie theater is dark, and psychologists have demonstrated in the lab that people startle more violently in dark than in light surroundings. At home, you can switch on the lights. And if you do watch horror films at home and have a good sound system with surround, consider switching the surround system off. Surround leads to increased immersion, which leads to enhancement of emotional response—including the startle response. Turn down the volume. Doing so will decrease the effect of the jump scare. It will not protect you from those nasty images, but there is a difference between seeing a nasty image on a 40-inch screen in your living room and seeing it on a cinema screen that is 40 by 30 feet.
You can also become a horror movie expert and learn to decode and predict such films. I have seen a lot of horror films, and I can usually tell when a jump scare is on the horizon—from the soundscape, the pattern of editing, plot progression, and so on. The thing is, horror movie directors know that horror buffs are good at predicting jump scares, so horror directors will try to cheat the buffs by manipulating the jump scare formula.
So, learning the conventions and the patterns of horror films may help you a bit, but it will not completely protect you from the jump scare. If you do know it is coming, though, you can employ coping strategies in an attempt to keep your fear response on a leash. At the very least, you can reduce the pre-startle anxiety, which may attenuate the startle itself. Effective coping strategies include self-distraction (think about something else) and reframing (try to remind yourself that it is just a movie). Behavioral interventions such as looking away or covering your eyes have limited immediate effect because they do not block the sound—but they do block the images. So there could be a long-term benefit, since it is the images that stick with you, as we have seen. Moreover, so-called antecedent coping strategies—which are employed before the frightening stimulus hits you—are more effective than response-oriented coping strategies for fear regulation. It is more effective to nip a fear response in the bud than to beat it into the ground once it has sprouted. That is because the fear response is pretty resistant to cognitive, rational control. Once it gets going, there is very little you can do. The startle response, however, is even more resistant. So even the use of antecedent coping strategies may be fairly ineffective.
My own favorite coping strategy for jump scares is to try to adopt an aesthetic, appreciative perspective. I try to see the jump scare as an aesthetic technique. If you approach a horror film from that perspective, you will find that you are less immersed. It does not always work, and it certainly does not work when the jump scare happens. In the very moment of the jump scare I am reduced to primitive biology—to primate grunts, dancing limbs, and fizzing nerve endings. But immediately afterward, I try to see how the jump scare was constructed. Doing so gives me a bit of psychological distance from the stimulus that just gutted me and allows me to appreciate the artistry of it. You can do the same—but do it at home, with the sound turned down and the lights turned on and perhaps a bit of alcohol in your blood.