Have you ever had an experience that was a little bit… well… spooky? Some people believe they have had encounters with ghosts, had premonitions that came true, or even met an uncannily accurate psychic.
Opinions can be divided about whether such experiences are real, though, with some insisting that everything must have a rational explanation.
For sceptics, supernatural beliefs may be hard to fathom, but there are at least six mental traits that push people into believing in the paranormal, Professor Chris French, a psychologist at Goldsmiths, University of London, said on Saturday at the London science festival, New Scientist Live.
Expectation effect
You might think that we sense the world around us simply by our senses. In fact, the brain’s complex circuitry means much of our conscious experiences are a mix of what the brain “expects” to perceive, based on past events – a system sometimes called “top-down processing”.
But sometimes the brain’s predictions are wrong. Top-down processing is behind most optical illusions – and can explain why someone might report seeing or hearing something that didn’t really happen.
The predictions are easily influenced by external suggestions, which can explain why people often claim to have had creepy encounters when they have been primed to expect them – like at a séance or a supposedly haunted location, as Prof French explains in his recent book, The Science of Weird Shit: Why our minds conjure the paranormal.
In an experiment, Professor Richard Wiseman at the University of Hertfordshire held a séance with a fake medium to see how easy it would be to convince members of the public that spirits were present. While some of the special effects were achieved with trickery, the medium’s misleading statements also influenced what people experienced.
For instance, the medium sometimes said, incorrectly, that the table was moving. Afterwards, a third of the participants said that the table had moved.
Some people reported extra effects they had imagined, like a strange sweet and acrid smell – presumably influenced by the spooky atmosphere.
In another study, a conjuror tried to convince people that he could use psychic powers to bend a metal key, by secretly switching the original key for a crooked one. After revealing the bent key, he put it down on a table and said: “It’s still bending.” About four in 10 thought it had warped in front of their eyes.
Pattern spotting
The human brain is designed by evolution to understand our surroundings by spotting patterns and connections.
For instance, when our ancestors were vulnerable to predators, they could have been more likely to survive if any suspicious rustles were taken as a threat until proven otherwise, said Prof French. “One Stone Age man assumes it’s a tiger and gets the hell out of there. If his neighbour stands there until he’s certain, that could be a more costly error.”
People vary in how prone they are to drawing conclusions during uncertainty – something that can be tested in the lab. This could help explain why some people believe they have had ghostly encounters, when others who were also present disagree, said Prof French.
Facial recognition
One clear case of incorrect pattern recognition is our tendency to “see” faces when they are not there. “You can see how this tendency might lead us to think we’ve seen a face in the shadows,” said Prof French.
Spotting faces is such an important part of human social lives, there is a part of the brain that has facial recognition as its main job. Babies just a few days old are especially interested in faces and spend more time looking at even quite simple drawings of faces than other drawings.
The brain’s interest in faces is probably also why images of Jesus and the Virgin Mary have been reported in chapatis, windows and plastered walls, said Prof French. In one study that tested people’s ability to spot faces in confusing visual images, paranormal believers were better at seeing face-like features that had been deliberately added – but also more prone to wrongly seeing faces that weren’t really there.
Unconscious powers
Some strange experiences can unknowingly be generated by our own bodies, for instance, when people use Ouija boards, where a glass or pointer seems to move around an inscribed alphabet, to spell out messages from spirits. Crucially, though, several people are usually resting their hand on the pointer for this to happen.
As long as no one is deliberately cheating, the messages are usually down to the “ideomotor effect”, when people make tiny muscle movements without realising it. With Ouija boards, if all those sat around the board are blindfolded, no meaningful messages can be produced, said Prof French.
The ideomotor effect can also explain dowsing, when some believe they can find underground water by the movements of hand-held sticks or a pendulum. Many people are convinced they can personally dowse, although whenever Prof French has tested dowsers by using bottles of water hidden in boxes, they have always failed.
False memories
Memory doesn’t work like a video camera that gives perfect replay. Whenever we recall a memory, the brain circuits that encode it become temporarily more malleable, with the result that the same memory is effectively re-recorded again and again.
If someone hears incorrect information about the event in question while recalling it, that can lead to the wrong facts becoming mixed in with the right ones. That’s partly why eyewitness reports of crimes are so often wrong.
For obvious reasons, the fallibility of our memory could contribute to people saying they have experienced paranormal events that didn’t really happen at all.
In another version of the “key-bending” demonstration, Prof Wiseman got the volunteers to watch the trick alongside another person who was a secret helper. When the helper insisted they had seen the key bend, the volunteer was more likely to report later that they had also seen this happen. “It’s a very simple manipulation with a big effect,” said Prof French.
Pre-determined conclusions
If a situation is uncertain, people tend to be more impressed by evidence that supports what they already believe to be true. “We tend to notice more of such evidence compared to evidence that contradicts our belief,” said Prof French. “We find it more compelling.”
This tendency, sometimes called “confirmation bias” helps to explain why some mediums and psychics can be very convincing.
They typically bombard their clients with multiple statements. Usually only a few will be correct, perhaps by chance – but these are more likely to be remembered. Prof French estimates he has tested about a dozen psychics in his career, and so far none has demonstrated any genuine abilities against his rigorous testing methods.
It isn’t only believers in the paranormal who may be guilty of this bias, though, Professor Neil Dagnall, a psychologist at Manchester Metropolitan University told i. Non-believers might also pay more attention to evidence that supports their sceptical stance, he said.
But belief in the supernatural is very widespread – shared by nearly half the UK population according to some surveys, with higher figures obtained if belief in superstitions are included. “A lot of people will claim to have had paranormal experiences themselves,” said Prof Dagnall.
“And even if people deny paranormal beliefs, they will say things like ‘touch wood’,” he said. Superstitions would also be classed as paranormal beliefs, as phenomena unexplainable by science, said Prof Dagnall.
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