The Winchester Mystery House in San Jose, California, is reputed to be the most haunted house in the world: more than 1,000 ghosts are allegedly in residence. This house, the inspiration for the movie Winchester (2018) starring Helen Mirren, originally belonged to Sarah Winchester, who was the widow of William Wirt Winchester, the gun-manufacturing magnate. Construction of the house began in 1884, completely unguided by any sort of coherent building plan, and it continued unabated until 1922.

Rooms, whimsical architectural features, and different wings and floors were added haphazardly, resulting in a rambling, bizarre puzzle of secret passageways, stairways, and alcoves. There are doors that don’t go anywhere, and windows with views into other interior rooms. There is even a room constructed specifically for conducting séances. At its peak, the house had more than 500 rooms, more than 10,000 windows, and many dozens of fireplaces and stairways. The Winchester Mystery House is a place where one could very easily become lost, and there are real scientific explanations for why people believe that ghosts thrive in such habitats. Scariest haunted house in Ohio is, in short, a very creepy place.

What is it that places like the Winchester Mystery House make us feel disoriented and anxious? These places have a combination of features that humans have learned to be cautious about. They could be associated with predators or other natural hazards. Or they may provide limited sensory information that restricts our freedom and can impair our ability to deal with emerging threats.

There are many types of creepiness. From dolls that look too real to clowns who are not allowed in certain places, there are many. However, the kind of creepiness most applicable to places is explained by a theory I developed with one of my students, Sara Koehnke. (The philosopher David Livingstone Smith has called this the ‘threat-ambiguity theory’ of creepiness.) This theory was first applied to people, not places. The idea is that people who are not conforming to the norm should be alerted because they can be unpredictable and pose a threat.

Our theory was tested in an online survey with 1,341 people. We asked them to rate how likely they thought a hypothetical creepy person would exhibit 44 different behaviors, including unusual eye contact patterns or physical characteristics like visible tattoos. Participants were then asked to rate 21 occupations and two hobbies they considered creepy. Participants were then asked to agree or disagree with 15 statements regarding the nature of creepy people. These results support the notion that creepiness is a response against ambiguity and threat. Our ‘creepiness detectors” were activated by non-normative, non-verbal and emotionally inappropriate behaviors and unusual physical characteristics. Males were more likely than females to be perceiving creepy people, while women were more likely that they would perceive creepy people as a threat to their sexual health.

We are easily frightened by people who act in strange and unpredictable ways and break the social conventions that allow us to understand their motives. They are ambiguous: Are they something to be afraid of? This ambivalence is what makes us feel ‘creeped out’. This is an adaptive reaction that can help you keep alert when danger is uncertain, and sharply focus your attention on the unpleasant ambiguity at hand.

Our theory received additional support in two experiments conducted by the Canadian psychologist Margo Watt and her colleagues. Watt asked people to rate their faces on creepiness, trustworthiness, and attractiveness. They also had to report details of creepy encounters that they had had and describe what a typical creepy person would look like. The results showed that women are more likely than men to perceive someone as creepy. There was also a lot of uncertainty around whether or not a person is trustworthy. Watt and her colleagues noticed a quick and nonconscious manner in which creepiness judgments were made. This suggests that these judgments are intuitive and do not require a detailed cognitive analysis.

Places can be scary for the same reason that people can. They present us with unclear information that can make it difficult to determine if the area is a danger or not. This is because places activate an evolved psychological adaptation called an ‘agent detection mechanism’.

Agent-detection mechanisms evolved to protect us from harm at the hands of predators and enemies. You will feel more alert and aroused if you are alone in the woods at night and hear something rustling in bushes. It will be as if you are being threatened by a malicious ‘agent’. Overreacting to a threat that turns out to be a gust or stray cat will not cause you any harm. If you don’t activate the alarm and there is a real threat, your mistake could cost you dearly.

All animals have evolved their own agent-detection mechanism precursors. A majority of primates are able to avoid sleeping on the ground, where predators like large cats and snakes could easily find them. Individual populations of prey animals, such as rodents and Sitka black-tailed elk, that have been protected from predation for many generations, such as Pere David’s and Sitka deer, show increased vigilance, tension, and response to stimuli and environments associated with ancestral predators. This is a testimony to the genetic durability and resilience of these adaptations. Vestiges of such responses have also been documented in human children who intuitively understand which environmental features offer the best hiding places from predators, and who prefer sleeping arrangements that minimize fears of things lurking beneath them.

We love places where you can see without being seen and eat without eating.

Research by environmental psychologists has confirmed that the most attractive natural environments contain things such as running water and open meadows surrounded by woods – the very features that would have been beneficial for the survival of early humans. People who found the “right” places performed better than people who didn’t. Over time, their genes also favored those who lived in more barren, less attractive environments.

However, places also have more abstract evolutionary relevant features. It turns out that our ancestors might have survived by being attracted to certain psychological features in places. Our creep detectors are activated when places lack the appropriate psychological features.

Jay Appleton, a British geographer, described two physical characteristics that make a place attractive or scary to people in his 1996 book The Experience of Landscape. A refuge is a safe, secure place where you can hide from danger. While the prospect is a clear and unimpeded view of the landscape, it refers to having one’s own view. Attractive locations offer a lot more prospects than a refuge. Randolph Hester, an American landscape architect, called it a ‘Womb with a view’.

This is why we love such spaces. Children love to play in enclosed spaces like cardboard boxes and treehouses, as well as in dense vegetation that provides them with a hiding place. These feelings can be explained by the concepts of refuge and prospect. The richness of details that can often still be recalled decades later can also help explain the magical quality of childhood memories. People who dine in restaurants prefer to be in corners and nooks. This is especially true if they can sit against a wall. They will also choose to settle for the middle of the room if all the other seats are taken. Appleton says that we enjoy the feeling of these spaces because you can see without being seen and eat without being eaten. The best environment for comfort is one that provides a lot of opportunity and refuge for the individual.

Research has confirmed that places that offer bad combinations of prospects and refuge are perceived as unsafe and dangerous: they can offer a lot of hiding places for people or things that might intend to do us harm. Environmental psychologists call this ‘legibility’. Legibility refers to the ease with which a location can be identified, organized into a pattern, and recalled. In other words, it is a place that allows us to move around freely without feeling lost.

The cinematic depiction of haunted homes has remained consistent over time. They are almost like a real haunted house on steroids. These fictional places act in a similar way to the supernormal stimuli” identified by ethologists studying animal behavior. Supernormal stimuli increase the vital features that are responsible for instinctive behaviors. This results in more intense performances of these behaviors. People’s current obsession with stimuli such as pornography and doughnuts are often seen as a response to supernormal stimuli’ that surpass anything that would have occurred naturally in their ancestral environment. These disorienting “supernormal stimuli” are common in haunted houses. They don’t pose a direct threat to us but because it is not clear if they are a threat. Therefore, the agent-detection mechanisms mentioned earlier are always on alert.

Large, old, drafty houses are filled with things that trigger hypervigilance for supernatural or natural malevolent forces. It’s easy to see that you are not the only one in this place.

Our escape options are also limited by haunted houses. Research consistently shows that we feel uncomfortable when we are intruded upon, especially in situations where escape is difficult. These feelings of discomfort are indicative of the fact we constantly scan our environment and assess our ability to flee if necessary.

We are all familiar with the Hollywood haunted house. It makes it difficult to flee. It can be difficult to find our way out of the darkness or slow us down due to its confusing layout. Hedges, iron fences, and crumbling staircases could make it difficult to escape. The ‘legibility of haunted houses is lacking: They are both a low prospect for us and a high refuge for the creepy crawlies that lie in wait to take us. A typical haunted home is large and dark with overgrown vegetation. It also has many architectural surprises such as hidden rooms or closets under the stairs. Also, basements and attics are must-haves. Spider webs, bats, and rats also make great accessories.

It is not an accident that the Hollywood ghost house is located in a remote and isolated area, far from the rest of society. Think of it as the off-season resort hotel at The Shining (1980). Even if communication was possible, it would take a while for help to arrive if bad things occur. In old horror movies, the telephones never work. The Blair Witch Project (1999) shows the same forced helplessness that is often the prerequisite for horror. Places that are unable to consent to people being isolated, such as orphanages, insane asylums, prisons, and other institutions, are considered frightening.

There is also the so-called “Hum”. Margee Kerr, an American sociologist who studies fear in her book Scream(2017), notes that infrasound can be produced by large buildings with rotting wood, exposed conduit work, and other structural defects. This makes the already creepy experience that much more frightening. Exposure to low-frequency sounds below 20 Hz can cause the sensation of ‘Hum. These soundwaves are known as “infrasound” but they are not audible to the human ear. However, their subtle vibrations can still be detected as an unidentifiable signal that can trigger our creep detectors. The ‘Hum” can cause sleeplessness or even nausea in some people. In 1998, two British scientists carried out an experiment on the Hum. This was then repeated in 2002 by Richard Wiseman, a psychologist, and Sarah Angliss (composer) at a concert at London’s Royal Festival Hall. The experiment exposed an unaware crowd to infrasound through loudspeakers. This resulted in widespread reports of discomfort and chills among concertgoers.

A recent study reveals yet another reason why dark, foreboding places come across as less than hospitable to us. Kurt Gray, an American psychologist, and his colleagues found that while both moral and impure people can imagine having an afterlife, their expectations of the type of afterlife they receive are very different. The ‘transcendent immortality of good people is where they are seen as living in spiritual paradise-like heaven, or, if they remain on Earth, living in open spaces such as deserts and mountaintops. The malevolent spirits and evil-doers of the past are more easily depicted in a trapped immortality’, where they live in extremely restricted environments such as a dense forest, haunted houses, or one room. These data show that old houses might be haunted or have a spiritual presence. We are more scared than we are comforted.

The enjoyment of horror movies and haunted houses could be a result of evolved psychological mechanisms.

It doesn’t just depend on the physical appearance of a building. The beliefs of the person who is visiting the house are just as important. People who believe in paranormal phenomena or have the expectation that strange things might be found in this place are more likely than others to engage in top-down cognitive processing that causes fear. These people can find it frightening to be in otherwise normal but unremarkable surroundings.

“Whistling past the graveyard” is an old expression that describes the unease humans feel around death-related places. These places are often viewed as haunted and become popular settings for horror movies, books, and films. The more horrific and traumatizing a death is, the more likely it will be that the site where it occurred becomes affected by it. Suicide deaths are more likely to infuse a location with a sense of foreboding. The most terrifying suicide spot is Aokigahara in Japan.

The forest, which covers 14 miles of beautiful vegetation, is located near Mount Fuji, Japan’s sacred mountain. It inspired the horror movie The Forest (2016). It has been associated with supernatural and mystical phenomena for a long time. In the 1800s, it was popular to abandon elderly people in order to allow them to die in the woods alone. Wataru Tsurumi, in his 1993 book The Complete Manual of Suicide describes the forest as “the perfect place for death”. Many suicide victims have found copies of his book.

The forest was featured in a Japanese novel that depicted two lovers who commit suicide in the 1960s. Suicides have been so common in the forest (105 deaths in 2003) that it is now regularly patrolled by police officers and volunteers who are trying to rescue people or find the bodies of others. There are signs throughout the forest that read: “Please consult the police before deciding to die” and “Your life is a valuable gift from your parents”. To rob the dead bodies, thieves patrol the forest in search of them.

It has all the trappings necessary to be creepy. The forest is densely packed with trees, moss, underbrush, and rotting logs. Compasses won’t work in this area due to the high level of magnetic iron found in the volcanic rock. Folklore says that spirits from people who have died there call others and lure them deep into the woods.

We are easily scared of haunted houses and other spooky places. So why would we ever want to be exposed? How has a commercial haunted house, which has an estimated 5,000 of these attractions in the United States every year, become an integral part of 21st century Halloween theatre? While I’ve focused on the terrifying, negative effects of horror, it is important to acknowledge that creepiness and horror can be attractive in certain circumstances. This is evident by the amount of money we spend every year on horror films and commercial haunted homes. The creepy can be a strange attraction for many people. What could be more entertaining than such things?

My theory is that the enjoyment of horror movies and commercial haunted houses taps into the same psychological mechanisms that help us learn from others’ experiences. As I wrote in Scientific American (2008), gossip is a key evolutionary benefit that humans have developed. People who kept up to date with the gossip of their tribe knew who was worth knowing, who was having sex with whom, and who was plotting against who. Thus gossipers knew how to take advantage of opportunities and avoid losing battles. These people were socially successful and their genes have been passed down through the centuries.

We are naturally drawn to stories about people we know, but stories about people who have been through extraordinary mishaps like shark attacks or plane crashes can be equally interesting. Stories about successful people can also interest us. In other words, our interest in ‘strategy-learning gossip’ is driven by the evolutionary advantages of acquiring survival and success strategies vicariously through the experiences of others. The same evolved psychological mechanisms that lead to our enjoyment of horror stories and haunted houses may also be responsible for our attraction to horror movies.

Watching others face serial killers and paranormal threats in the comfort of a movie theater allows us to mentally practice strategies we might use if we find ourselves in similar situations. It is common to hear the audience gasp when a character opens the door to a room or hides in an inopportune spot. We are better equipped to handle creepy encounters after we have witnessed what happens in horrifying circumstances.

Similar to the above, walking through a haunted house commercial can give us valuable feedback about ourselves. It can be helpful to identify the types of things that are frightening to us. Examining our emotional reactions to these unsettling experiences can help to gauge our readiness to deal with paranormal encounters. If such an eerie encounter ever happens, this could help us determine which strategies are most effective. Horror can still be entertaining, even if it isn’t the real thing. It can also help us prepare for the Zombie Apocalypse or other terrifying scenarios.