
The science of cinema: how watching movies affects the human body
The entire point of cinema – in its purest form, at least – is to elicit an emotional reaction from an audience, with movies capable of wringing out everything from laughter and tears to fear-inducing panic and heart palpitations.
People fall in love with movies that affect them on a personal level, but beyond the psychological effects films can have on viewers, there are more pronounced physiological symptoms. Being propelled out of a seat by a well-timed jump scare is the most obvious, but it runs much deeper than that.
Not every feature needs to generate a visceral, primal response, but there’s a sizeable scientific basis in the human body experiencing both positive and negative effects from a filmed work of fiction. Returning to horror as a baseline, studies have shown that it can be just as helpful in calming feelings of anxiety as creating them. One genre, two wildly different outcomes, but equally indicative of cinema’s power.
Unless it’s a particularly shoddily-made or uninteresting picture, the base impulses of the human condition can be triggered by an effective movie. Watching characters walk headlong into certain doom, the promise of an unseen evil lurking around the next corner, an awe-inspiring action sequence, or a deafening shootout can all have similar effects.
A large part of that is down to the pesky amygdala, the neural centre of the brain responsible for reacting to fearful situations and scenarios. Breathing increases, heart rates shoot up, blood pressure steadily rises, and adrenaline spikes, making cinema much less of a passive experience than anyone could have predicted in the late 19th and early 20th centuries when it was a new-fangled technology.
The adrenaline rushes stemming from horror, thrillers, and action flicks all have knock-on effects that extend to other parts of the body. Whether it’s gasping with shock, screaming with terror, getting sweaty palms from the nerve-wracking tension on display, or an isolated on-screen incident that literally takes the breath away, it’s all connected to the fight or flight response that’s inbuilt into every single person.
Digging into the science of it all, sympathetic nerve fibres connected to the heart release the neurotransmitter noradrenaline, narrowing the blood vessels in the bodily organs that don’t quite fit into the ‘essential’ bracket to allow more to make their way to the heart and brain. Nobody watches a movie expecting all this to be happening on the inside, but cinema literally seeps into every fibre of the being.
Goosebumps, dilated pupils, expanding muscles in the airway to better regulate breathing, and self-injected rushes of dopamine brought on by a natural high can all be triggered by a film and on multiple occasions.

The body is a medical marvel for a myriad of different reasons, but one of the most unexpected – compared to the breadth of human history – is that two hours of mass-marketed entertainment crafted by a cast and crew numbering into the hundreds can do all of that and more to any given person.
Those are just the subtleties, too, with the effect often being a great deal more obvious and pronounced. Countless movies have worn it as a badge of honour that audience members have lost consciousness, violently thrown up, and occasionally even died during screenings, even if the scientific explanation for blowing chunks at a gnarly horror doesn’t quite have a nailed-down explanation.
“We just know that there are certain people who are quite sensitive to noxious stimuli like that,” neurologist Peter Tai explained to Globe and Mail. “More often, you hear about it in kids who don’t like needles and faint every time they see a needle or every time someone actually sticks them with a needle.”
“With various types of noxious stimuli, often painful or even emotional, it affects people’s vascular reflexes and often either that makes your heart race, because you’re scared and it’s a fight-or-flight response, or sometimes, paradoxically, it can make your heart kind of slow down,” the man of science continued. “Your heart slows down, your blood pressure drops, and it’s not enough blood pressure to support your level of consciousness. You end up passing out.”
Fortunately, it’s not all doom and gloom, with proven health benefits from consuming cinema. Around 15 minutes of hard-earned laughter has a similar effect on the cardiovascular system as exercise, so anyone who can’t be arsed going out for a casual stroll or light jog can simply pop on a comedy they know is guaranteed to split their sides for the same effect without even having to get up off the couch.
For decades, movies have been accused of influencing and inspiring viewers to do everything from replicating dangerous feats depicted by daredevil professionals to committing cold-blooded murder. Those links have always felt somewhat tenuous, but as it turns out, the body is directly affected by films in a number of uncontrollable ways that can’t be turned off, quietened down, or ignored.
Sit down, strap in, and go along for the ride because whether anyone wants to admit it or not, cinema is going to change them in one way or another.