Muscle-reading is a tactic often employed by psychological illusionists, a type of magician otherwise known as a mentalist, to give the illusion that they are reading your mind. Just as with the Ouija board, the method that these mentalists actually use (muscle-reading) is caused by something called the ideomotor effect.
Automatic writing (Psychography) is also a result of the ideomotor effect. Usually, the mentalist will ask a participant to hide an object
somewhere in a large area.
They then either hold on to the participants
wrist or get the participant to hold on to their wrist, whilst acting as though they are reading directions from the participant’s mind.
They do so by getting the participant to consciously think the directions. What is actually happening is ideomotor movement – the mentalist is simply muscle-reading
which anyone can learn how to do. Because the illusionist is in
physical contact with the participant, they can test the physiological
response caused by the ideomotor effect.
The mentalist very subtly and gently moves the participant’s arm
around in all directions whilst keeping them distracted so they don’t
notice, in order to find the path of least muscular resistance – this is
the direction that the object has been placed in.
[ Image from Pixabay - Public Domain - http://pixabay.com/en/head-question-mark-think-674129/ ]