In the newly released film Ouija: Origin of Evil, purposefully deceptive Ouija-ing becomes all to real for a medium mother when the scam actually brings an evil spirit into her home and possesses her young daughter. Directed by Mike Flanagan of Hush, the movie is supposed to be really scary. What’s not actually scary, however, are Ouija boards.

Ouija boards, if used in earnest, are subconsciously operated by the user. It comes down to a phenomenon called the ideomotor effect, which causes behavior that is unconsciously initiated.

The name comes from a physician named William Carpenter, who in the 1800s examined the use of a recent phenomenon: the Ouija board. He observed that muscular movements could happen outside of someone’s conscious awareness: When users all reach their hands out to the planchette (the small moveable piece of wood), ask a question, and begin to move this indicator, what is spelled out across the board’s alphabet isn’t the answer of a spirit — it’s the result of a subconscious thought.

According to Philip Shenefelt in the American Journal of Clinical Hypnosis, ideomotor actions happen when “intention or thought is transmitted to the motor cortex at a subconscious level, coordinated by the cerebellum, and sent down spinal nerves to the appropriate muscles, inducing movements not visible to the naked eye.” That’s when unconscious, muscular movement occurs.

A Ouija board from 1894.

In a 2012 experiment, University of British Columbia researchers also discovered that the ideomotor effect didn’t just result in involuntary muscular movements — it could also reveal thoughts not readily available to a conscious mind. Twenty-seven subjects were asked to perform two tests where they were asked random questions. In one of the tests they just had to reply “yes” or “no;” in the other, they had to move the planchette on to the “yes” or “no” of a Ouija board. They discovered that when the users were just guessing their answers, collectively, they were 15 percent more accurate when responding with the Ouija board.

The researchers concluded that this might indicate that ideomotor actions could reveal implicit semantic memories — participants had the answer deep in their subconscious, but it took moving the planchette to ignite that memory. The researchers describe it as if we all have an “inner zombie” — a non-conscious system that moves without purposeful thought.

It’s very possible that the name “Ouija Board” itself, is a result of the ideomotor effect from 1890. According to Atlas Obscura, a group of people — including a businessman named Charles Kennard, who was one of the earliest to market the board — decided that they should ask the board itself, what it should be called. When the group moved the planchette, the word “ouija” was spelled.

One member of the group, a medium named Helen Peters, told the group afterward that she in fact was wearing a locket with an image of a woman, and on this image was the word “ouija.” Kennard asked Peters if she was thinking about the locket when they were consulting the board; she answered no. But if we consider the ideomotor effect, it’s pretty likely her subconscious thoughts might be emerging through the movement of her hands.

Photos via Wikimedia Commons, Giphy