From Marie Tussaud’s Chamber of Horrors to Disneyland’s Haunted Mansion to horror-themed escape rooms, haunted house attractions have terrified and delighted audiences around the world for more than 200 years. Today thousands of haunted houses operate in the U.S. alone. This thriving industry was worth $300 million in 2013, according to an NBC report.

In recent years, the haunted house boom has caught the attention of psychologists and social scientists. A small but growing contingent of researchers have turned to these attractions to study fear. Though haunted houses are in the business of creating illusions—an area of expertise for us—the research they facilitate can have important applications in real life. They help scientists understand the body’s response to fear and how we manage to discern some situations as enjoyably thrilling and others as truly terrible. Among the surprising findings: having friends close at hand in a haunted house might make you more jumpy, not less so.

A field study published earlier this year by researchers at the California Institute of Technology set out to examine how the human body responds to threats and whether the presence of friends would buffer or amplify the experience of fear. The scientists teamed up with The 17th Door, an immersive haunted experience in Fullerton, Calif.

The 17th Door attraction is somewhere in the middle in terms of its fear factor. It’s not suitable for young children, though teens age 16 and older can participate, provided their legal guardians sign a waiver on-site. But it’s also not as punishing as “extreme” haunted houses in which visitors live “their own horror movie,” through such scenarios as being waterboarded or having insects thrown into their mouth. Even so, the roughly 30-minute walkthrough at 17th Door, set in a fictitious penitentiary, includes mimicked suffocation, actual electric shocks, live cockroaches, brief submersion in water and being shot with pellets by a firing squad while blindfolded. Guests are given a safe word to exit the experience: “mercy.”

While this description might deter some visitors, its blend of complex horrors was a special opportunity for the scientists involved. “There are limitations to conducting this sort of research in the laboratory with smaller spaces,” says psychologist and study co-author Sarah Tashjian, who will be at the University of Melbourne in Australia starting next year. A large and complicated haunted house, by contrast, allows for an immersive experience, illuminating many aspects of frightful feelings.

Tashjian and her team conducted their research with 157 adults, who each wore a wireless wrist sensor during their visit. The sensor measured skin responses linked to the body’s reactions to stress and other situations. When the sensor picked up, for example, greater skin conductance—that is, the degree to which the skin can transmit an electric current—that was a sign that the body was more aroused and ready for fight or flight. In addition to this measure, people reported their expected fear (on a scale of 1 to 10) before entering the haunted house and their experienced fear (on the same scale) after completing the haunt.

The scientists found that people who reported greater fear also showed heightened skin responses. Being with friends, Tashjian and her colleagues further found, increased physiological arousal during the experience, which was linked to stronger feelings of fright. In fact, the fear response was actually weaker when people went through the house in the presence of strangers.

Though Tashjian and her colleagues had initially wondered whether friends might make the experience less harrowing, she feels their study’s findings also make sense. “Because the haunted house was entertaining and exciting, as well as scary, it is possible that being with people you know made the entire experience more arousing,” Tashjian explains. “There was likely a contagious feedback loop with friends that wasn’t as strong among strangers.”

Other investigators have turned to haunted houses to understand how fear and enjoyment can coexist in recreational horror and the mechanisms that people apply to minimize or maximize their fear. In a 2020 study led by Marc Malmdorf Andersen of Aarhus University in Denmark, scientists joined forces with Dystopia Haunted House. The Danish attraction includes such terrifying experiences as being chased by “Mr. Piggy,” a large, chainsaw-wielding man wearing a bloody butcher’s apron and pig mask. By some accounts, 5 percent of Dystopia Haunted House’s guests are unable to complete the tour.

In the Dystopia Haunted House experiment, people between the ages of 12 and 57 were videotaped at peak moments during the attraction, wore heart-rate monitors throughout and reported on their experience. The data showed an inverted-U-shaped relationship between entertainment and fear. Participants’ fright related to large-scale heart-rate fluctuations while their enjoyment was linked to small-scale ones. The results suggest that fear and enjoyment can coexist, but they rely on a balancing act, where the dynamics of physiological arousal, as seen in heart-rate fluctuations, are “just right.”

An earlier study by the Recreational Fear Lab at Aarhus University, led by Mathias Clasen, also used Dystopia Haunted House to gain insight into how “adrenaline junkies” and “white-knucklers” manage their fear. Some visitors applied strategies to minimize fear, such as covering their eyes and reminding themselves that the threats were not real. Others used role-playing and sought out exposure to scary stimuli to maximize terror. Both groups reported similar levels of satisfaction, suggesting that consumers upregulate and downregulate their fear arousal in pursuit of the optimal experience.

Understanding these patterns has real-world utility. Tashjian notes that learning what factors amplify and reduce threat responses can help people with post-traumatic stress disorder or anxiety. She adds that you can help to consciously regulate your body’s fear response “by practicing deep-breathing exercises or meditation [and] mindfulness.” These practices can benefit many people facing stressful or threatening experiences in day-to-day life.

But in the meantime, if you want to get really scared at your next haunted house, keep your eyes open, lean into the scary moments—and bring some friends along.

Are you a scientist who specializes in neuroscience, cognitive science or psychology? And have you read a recent peer-reviewed paper that you would like to write about for Mind Matters? Please send suggestions to Scientific American’s Mind Matters editor Daisy Yuhas at pitchmindmatters@gmail.com.