9. Ideomotor Effect
The Spiritualist movement was pretty big in the 1840s and 1850s. It provided a way for people to talk to their dead loved ones. One method of communication was the Ouija board. Still popular today, the board was covered in letters, numbers, and simple words (like “yes” or “no”). People would then place their hands on a wooden piece called a planchette and ask the spirits a question. A ghost would respond by moving the planchette from letter to letter, spelling out a response (or unleashing Captain Howdy).
Another creepy method for interacting with spirits was table tilting. During a séance, people would gather round a table and place their hands on the tabletop. To everyone’s surprise, the table would start moving by itself. It might tilt up on one leg, levitate off the ground or scoot around the room.
Con men were definitely involved in some of these incidents, but were all these encounters frauds? Renowned physicist Michael Faraday wanted to find out. Through clever experimentation, Faraday discovered that the tables were often moving thanks to the ideomotor effect. This is when the power of suggestion causes our muscles to move unconsciously. People expected a table to move so they unintentionally moved it. A similar event took place in 1853 when four doctors held an experimental séance. When they secretly told half the participants the table would move to the right and half it would move left, the table didn’t budge. But when they told everyone it would move in one direction, the ideomotor effect struck again! This same principle applies to the Ouija board. It’s our own muscles that are doing the spelling, not the spirits.