Pendulum Divination: How People Use It and Why the Weight Moves

What a pendulum is and what it is used for

The tool is simple: a pointed or rounded weight, often a crystal, metal or wood, hung from a cord. The user rests an elbow on a table, holds the end of the cord between finger and thumb and waits for the weight to settle. Then they ask a question and watch which way it moves.

Uses range from choosing between options to dowsing for water, objects or, in some traditions, finding a lost item on a map. A pendulum board adds letters, numbers and the words yes and no on a printed sheet so that the swing can spell out a reply, which makes it look like a cousin of the Ouija board.

Setting up a yes and no code

Before asking anything, users agree a code with the pendulum. There is no standard, so the convention is whatever you choose and then keep.

1. Hold the pendulum still and say or think, show me yes. Note the movement, often a swing back and forth or a clockwise circle.
2. Do the same for no, and for the answer meaning unsure or ask again.
3. Phrase questions so that a yes or no actually answers them. How is the day going cannot be answered by a swing.
4. Ask one question at a time and let the weight settle in between.

Why the weight moves: the ideomotor effect

In 1852 the physician William Carpenter described the ideomotor effect, in which a thought can produce small muscle movements that the person does not feel making. The following year Michael Faraday showed the same thing in the table-turning craze: when he arranged a device so that the sitters could see whether their hands were pushing, the table stopped moving once they knew.

A pendulum amplifies it. A hanging weight swings a long way from a very small push, and the user's fingers are never perfectly still. If you expect yes, the hand makes the tiny movements that start a yes swing, and you experience the weight as acting by itself. That is why the pendulum often agrees with what you already hoped or feared.

The test you can try yourself

The effect is easy to check at home without believing or disbelieving anything. Ask a pendulum a question whose answer you do not know and cannot guess, such as the number on the top card of a face-down deck, and ask a friend to record the answers without telling you if you are right. A user whose pendulum is tracking something other than their own expectations will do better than chance over many tries. The ideomotor account predicts that the results will look like guessing, and that is what controlled tests of dowsing generally have found.

A second test: try the same question with your eyes closed, or with the pendulum held by someone who does not know the answer. If the swing changes with who is holding it, the source is the holder.

Using a pendulum as a thinking tool

Some people use the pendulum knowingly as a way of surfacing a preference, and there is a modest honest use for that. If the weight swings towards no when you ask whether you want to take a job, your reaction to that answer, whether relief or dismay, tells you something about what you wanted.

The tool is then working like a coin toss, where the point is the feeling you notice while the coin is in the air. Used that way it is harmless. Used as an authority on health, money or other people's secrets, it is not.