Chevreul's Pendulum

You don't have to be delusional, psychic, or gullible to experience the ideomotor effect. With this very simple activity, you can demonstrate the power of an idea to inspire action. It is named after Michael Eugene Chevreul who used this pendulum to explain how an unconscious movement can be made apparent by amplification. A version of this activity can also be found in The Fifth Discipline Fieldbook by Peter Senge (Senge, Peter M. The Fifth Discipline Fieldbook: Strategies and Tools for Building a Learning Organization. New York: Currency, Doubleday, 1994.)


To demonstrate the power of an idea to influence action


  • a heavy metal washer or bolt tied to a 12 inch string
  • paper
  • a pen for each person


Any number sitting at tables


15 minutes


Explain that we don't always realize the impact an idea can have on our actions. Sometimes just the suggestion of a concept is enough to start a bit of motion in a new direction. Suggest that this activity is a chance to demonstrate the power of an idea over our actions.

Distribute a washer, string, paper and pen to each person. Ask them to draw the four points of a compass, North, South, East, and West, on their paper. Then have each person hold their string in hand with the washer hanging over the center of their compass and their elbow resting on the table.

Instruct them to hold their hand totally motionless so the washer is suspended absolutely still about an inch above the center of their compass. Then tell them that they are to imagine that the pendulum they have created is swinging ever so gently North to South. Caution them to keep their hand and body as still as possible but to think "North-South." After a few moments, several people will report movement of their pendulum in the correct direction.

Some people will not experience the effect. In those cases, encourage people to be patient and keep trying. Not everyone will be successful and that's alright.

For those who have been successful with the effect, challenge them to see if they can induce their pendulum to change direction and swing East to West.

After a few moments of experimentation, gather everyone for a brief discussion.


  • How did you react when you were able to make your pendulum move?
  • What did you do to ensure your hand remained as still as possible?
  • How can you explain the movement of the pendulum? (The length of the string amplifies tiny movements of the hand, arm, and fingers that are initiated by ones thoughts.)
  • If you were not able to control the pendulum, why might that be?
  • Describe a time you experienced someone's ideas to be especially inspiring.
  • Describe a time another person's words left you completely deflated.
  • What are some examples of when ideas have power over our actions?
  • What are some of the positive and negative implications of this particular power that ideas have?
  • If a thought can initiate an action, what are the implications for leaders who want to articulate a vision, or describe an organization's mission?
  • If thoughts can lead to actions, what would be the effect of repeating the same thought - either positive or negative - over and over in your mind?