ideomotor effect

The ideomotor effect refers to the influence of suggestion or expectation on involuntary and unconscious motor behavior. The movement of pointers on Ouija boards, of a facilitator's hands in facilitated communication, of hands and arms in applied kinesiology, and of some behaviors attributed to hypnotic suggestion, are due to ideomotor action.

Ray Hyman ("How People Are Fooled by Ideomotor Action") has demonstrated the seductive influence of ideomotor action on medical quackery, where it has produced such appliances as the "Toftness Radiation Detector" (used by chiropractors) and "black boxes" used in medical radiesthesia and radionics (popular with naturopaths to harness "energy" used in diagnosis and healing.) Hyman also argues that such things as Qi Gong and "pulse diagnosis," popular in both Traditional Chinese Medicine and Ayurvedic medicine as allegedly practiced by Deepak Chopra, are best explained in terms of ideomotor action and require no supposition of mysterious energies such as chi.


The term "ideomotor action" was coined by William B. Carpenter in 1852 in his explanation for the movements of rods and pendulums by dowsers and some table turning or lifting by spirit mediums (the ones that weren't accomplished by cheating). Carpenter argued that muscular movement can be initiated by the mind independently of volition or emotions. We may not be aware of it, but suggestions can be made to the mind by others or by observations. Those suggestions can influence the mind and affect motor behavior.

Scientific tests by American psychologist William James, French chemist Michel Chevreul, English scientist Michael Faraday (Leonard Zusne and Warren H. Jones, Anomalistic Psychology: A Study of Magical Thinking, p. 111), and American psychologist Ray Hyman have demonstrated that many phenomena attributed to spiritual or paranormal forces, or to mysterious "energies," are actually due to ideomotor action. Furthermore, these tests demonstrate that "honest, intelligent people can unconsciously engage in muscular activity that is consistent with their expectations" (Hyman). The tests also show that suggestions that guide behavior can be given by subtle cues (Ray Hyman, "Cold reading: how to convince strangers that you know all about them," Zetetic. 1977; 1(2):18-37).