Now is the time of year when many of us actually look forward to being scared, whether by watching horror movies or visiting a haunted house. There are biological and mental processes that explain why we sometimes enjoy fear and sometimes…er…fear it.

Whether it’s watching a horror movie, going to a haunted house or even riding a rollercoaster, most of us like a good scare every now and then. As Halloween approaches, people are increasingly looking for ways to experience the fun side of fear. But why are human beings capable of enjoying the sensation of being scared? There are a host of biological, psychological and social factors that influence our experience of fear, determining whether it will be pleasurable or miserable. Here we look at some of the science underlying fright.

“Fear, that most primitive of emotions, is good, at least when it is kept under control. It is essential for survival, allowing an organism to detect a potential threat to its life,” science and psychology blog Neurophilosophy explains. “Too much fear, however, can lead to pathological conditions such as anxiety, phobia, paranoia or post-traumatic stress disorder.”

The difference between controllable fear and uncontrollable fear depends on the interaction between biological impulses and mental stimuli. The initial physiological reaction to fear involves the “fight or flight” response, which is caused by the autonomic system releasing adrenaline, noradrenaline and the steroid cortisol. The result is a faster heart rate, quickened breath, pupil dilation to enable better vision, an increased metabolism to boost energy and more focused attention for faster decision-making.

Exploiting the fight or flight reaction is what makes fear a pleasurable experience. If the brain understands that there is no actual risk of being harmed in a frightening situation, it can overcome the behavioral expectations set up by physiological changes and learn to enjoy the adrenaline rush. A broader situational awareness is necessary for this transition into controllable fear, and that often depends on maturity.

“Young children may overestimate the risk of harm and experience true ‘fear.’ When that happens you see the child cling to a parent and cry, convinced there’s a very real chance of harm,” David Rudd, then a clinical psychologist at Texas Tech University, told LiveScience. However, “adults may well scream but quickly follow it with a laugh since they readily recognize there’s no chance for real harm.” Rudd is now the Dean of the College of Social and Behavioral Science at the University of Utah.

Watching horror movies is a Halloween tradition. Developments in neuroscience shed an interesting light on how visual depictions of frightening scenarios can trigger a tension between instinct and reason similar to that of the fight or flight response. When watching a horror movie, a person’s heartbeat increases, palms sweat, skin temperature drops a few degrees, muscles tense and blood pressure spikes.

“The brain hasn’t really adapted to the new technology [of movies],” Glenn Sparks, a professor of communication at Purdue University, told WebMD. “We can tell ourselves the images on the screen are not real, but emotionally our brain reacts as if they are…our ‘old brain’ still governs our reactions.”

Scientists say that while watching a scary movie, sensory data received by the eyes and ears is transmitted to a cluster of neurons in the brain known as the amygdala, which is responsible for immediate processing of emotional information, particularly positive feelings such as love and pleasure.

“So as the zombie breaks through the door or the murderer leaps from the closet, your amygdala gets juiced just as it would by a home run in the bottom of the ninth, unleashing a brain- and body-energizing cocktail of hormones,” Wired.com explains. “But while this is happening, information also travels to your prefrontal cortex, the part of the brain responsible for consciously evaluating danger. It tells you that the movie is just a movie.”

However, psychological influences also play an enormous role in our conception of fear as well. Another popular activity around Halloween is visiting a haunted house or another scary site. Social conditioning is the reason we find some settings frightening instead of others.

“For humans, the terrifying landscape is one they don’t understand,” Jerry Moore, an anthropologist at California State University, Dominguez Hills, told Discovery News. “Take people out of their known environment and put them in another — they are frightened.”

The unknown is at the core of every fearful place. An unfamiliar setting with areas that are hidden or obscured can induce anxiety and allow the mind to project images to fill in the gaps. Hence the impression that a dark corner contains a malevolent figure or that a billowing curtain is moved by ghostly influence.

Of course, death is the greatest unknown, which is why graveyards, catacombs and crypts rank high on people’s lists of the scariest places. The imagination also sees terrors where there are none. For millennia, the unexplored regions of the world were thought to be home to monsters or dreaded sea creatures. Ancient gathering places also have a powerful sway because places of ceremony carry a disproportionate weight in people’s minds, making battlefields, worship sites and arenas seem imbued with superstitious power, especially if the culture that revered them is no longer around.

But what about nightmares, which induce the sort of fear we have almost no control over? Traditionally, nightmares were viewed as the subconscious byproduct of psychological issues that afflict our waking lives. But recent advances have led some researchers to approach nightmares as a problem in themselves, attempting to replace negative imagery with positive imagery. Other schools of thought claim that nightmares may serve a beneficial purpose by helping us overcome our fears.

“One of the newest theories about the function of nightmares comes from Ross Levin and Tore Nielsen,” the New Yorker reports. “Their view is that dreaming may serve the adaptive function of ‘fear memory extinction’: desensitizing the sleeper to something scary through repeated exposure in a less frightening context.”

Regardless of the scientific explanations for fear and why we either hate it or enjoy it, the best option this coming Halloween may be to watch a scary flick, go to a haunted house and not over-think the experience.

Earlier

Light Friday: The Big Business of Halloween

Study Undertakes Psychology of Superstition

Resources

The Neurobiology of Fear
Neurophilosophy, Oct. 31, 2006

Why We Love to Be Scared
by Charles Q. Choi
LiveScience, Oct. 30, 2006

Why We Love Scary Movies
by Richard Sine
WebMD, Oct. 25, 2007

That Nearly Scared Me to Death! Let’s Do It Again
by Brandon Keim
Wired.com, Oct. 31, 2007

Scary Places: Landscapes of Terror
by Larry O’Hanlon
Discovery News, 2010

Nightmare Scenario
by Margaret Talbot
The New Yorker, Nov. 16, 2009