What Makes Us Jump In Horror Films?

Exploring the science of the jump scare. Cheap trick, or essential ingredient?

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Of the hundreds of thousands of horror movies out there, which do you line up this Halloween? Your decision will likely be informed by the marker of a truly great horror film: a powerful, inalterable image.

You could go for Linda Blair’s scarred, vomity and putrefied face from The Exorcist, Norman Bates’ cross-dressing silhouette in Psycho, or Danny’s first encounter with the creepy British twins in The Shining, all of them markers we’ve used to define the genre. Yet while these images may have scarred our brains (and childhoods) forever, we seem to overlook the sound design built around them. These images alone are nothing without the atmosphere of claustrophobic diegetic sound and a moody score.



Sound design is the true source of fear in your favourite horror movies — not the fear that may haunt your dreams in weeks to come, but a primal fear, best typified by whenever this happens:

Or this:

Hell, even Batman tries to pull it on you:

These are jump scares: those much-maligned yet all-consuming jolts that seize your entire body for a painful split second, clenching your stomach and, for those with a weaker bladder, making you pee a little. Horror fans love that shot from The Exorcist III (which is otherwise a truly terrible movie); it constantly finds its place at the top of “Top Jump Scares” lists.

But so many more movie-goers scoff at the jump scare as a cheap tactic. Admittedly, it’s pretty hard to argue with them: it’s the cinematic equivalent of “Boo!” Even so, they’ve remained the mainstay of horror not only because these sneaky bastards are 100% effective but, due to their simple design, they’re pretty easy to pull off. You’ll notice too, they’re completely rooted in the manipulation of sound: in a slow build to a sudden and violent release. The idea is to build up a false sense of security, forcing the audience into uncomfortable expectation. In that state, it’s a cinch to catch you off guard with an excruciating explosion of sound.

In the annoyance and shame we feel immediately afterwards, we ignore the actual process of how that instant fear takes total control of our bodies. In fact, knowing the science actually makes all of that butt-clenching a worthwhile — even desirable — experience.

The Science Of The Jump Scare

In the world of horror cinema we call it the jump scare but, in the science world, it’s the “Startle Reflex” — a primal neurological circuit hardwired into your anatomy. The reflex is the result of evolution, developed over eras in which humans had to scavange their meals around ferocious toothed predators and what not. Neuroscientist and author of The Universal Sense: How Hearing Shapes the Mind, Seth Horowitz, is a prominent thinker on the topic. Speaking to those pedantic nerds on the Radiolab podcast, he says, “A sudden loud noise activates a very specialised circuit from your ear to spinal neurons, it’s the ‘Startle Circuit.’ If you suddenly hear a loud noise, within 50 milliseconds your body jumps and begins the release of adrenaline, with no consciousness involved. It’s five neurons.”

Five neurons. To compare, put yourself in the shoes of the cop from that Conjuring clip. According to Radiolab, the mere neurological process of spotting the ghostly maid lurking in the laundry then deciding to approach her, without even moving a muscle, will cost you somewhere in the vicinity of a quarter of a second (that’s about 250 milliseconds). They point out the existential crisis built into all of this: everything we see and experience on a day-to-day basis has technically already happened. The time it takes your brain to process visual images kind of puts your consciousness on a delay — the kind of delay poor Aretha Franklin seems to be living during her recent press tour. On the other hand, the reflexive reaction to the jump scare takes about a fifth of that time, close to 20 times faster. In these moments, our bodies and minds are separated. The body is shocked before our conscious brains have even realised something’s amiss; that burst of sound identifies Michael Myers as dangerous before you’ve even processed the knife in his hand, or that freaky mask on his face. These alarming sounds plough their way into your body at speeds faster than any other sense you have.

The Jump Scare In The “Found Footage” Genre

In this light, jump scares are a kind of dispensable pleasure, a one-off chance at living in the moment with the audience around you. And the real annoyance of it all is then knowing the exact timing of the scare, killing its impact. Luckily, filmmakers have gotten pretty creative with their execution. Take the above Insidious clip, for example. Director James Wan is downright subversive in his delivery, throwing in a fake out just before smacking you in the face with a genuinely startling climax. However, it’s in the found footage subgenre that you really unearth a new wave of jump scares. It makes sense: the subgenre itself is loud and tacky, yet unavoidably immersive. Here a couple to add to your Halloween playlist.

The breakout hit [Rec], from Spaniards Jaume Balagueró and Paco Plaza, was a shot in the arm for the found footage gimmick, spawning a load of shoddy imitators. For geniuses Balagueró and Plaza, though, giving you the first-person perspective in a quarantined apartment building in which the occupants are slowly being consumed by a weaponised strain of demonic possession is like shooting fish in a barrel. None more unashamedly effective than these doozies:

Or take the martial arts maestro behind The Raid, Gareth Huw Evans, put the found footage gimmick in his more than capable hands, and you’ve got yourself Safe Haven, a segment from 2013’s V/H/S 2. It’s an orgiastic bloodbath of a short film, piling in excessive gore, demon birth, ritualistic suicide and more family-friendly favourites. It has to be seen to be believed, so maybe just watch the first couple of minutes here:

It’s all about that sound.

The more you experience the jump scare, the more you realise there is something alluring about the thrill of an experience more immediate and visceral than most things in your life — let alone what you see on a movie screen. In the moment of a jump scare, you’re the pre-historic man evading death, not the schlub sitting in a cinema masticating on popcorn. This is genuine animal fear.

Halloween is the time we give crap horror movies our ironic attention but I say: screw that, enjoy them everyday. At the very least, their cheap, hackneyed jump scares will get you in touch with the outside world like nothing else can.

Bonus clip:

Sean is a freelance writer based in Melbourne who has been published in FilmInk and Beat magazine. He also tweets irregularly from @ssebast90.