“You have a great need for other people to like and admire you. You have a tendency to be critical of yourself. You have a great deal of unused capacity which you have not turned to your advantage. While you have some personality weaknesses, you are generally able to compensate for them…”

Do you think so?

In a classic psychological experiment, Bertram Forer demonstrated that the vast majority of people would agree that the sentences above were (part of ) a very good description of their personality… if they were told it was an analysis which had been drawn up specifically for them.

It seems there’s a great persuasive magic in “Barnum statements” like these – statements that sound as if they’ve been tailored for you, but in fact are vague enough to apply to anybody.

I was reminded of the power of the “Forer effect” recently by Ben Wilson’s excellent new book, Change Your Thinking, Change Your Shape, because I think Ben uses it very well.

A large part of the book is made up of a series of short chapters about what he calls “blocking beliefs” which apparently prevent people from getting into amazing shape. Examples include “food makes me happy” and “being healthy costs too much money”.

The vast majority of his readers (who, we can assume, are not in amazing shape) will probably subscribe to at least some of these beliefs. As they read the book, they become more and more convinced that Ben understands the unique challenges they are facing… and thus become more and more open to his later suggestions (which strike me as very sensible ones).

Barnum statements have become associated with conmen and tricksters, such as fake psychics. But the truth is, the technique can be used probably even more effectively by people whose interests coincide with yours. You want to lose weight: Ben Wilson’s reputation as a fitness expert is bound up with your success in achieving that.

Part of the magic of Clean Language comes from a similar effect. When you use another person’s unique words back to them, and as you help them to explore their individual metaphors, it feels as if you really understand them. It’s as if you can see into their unconscious mind…

It’s a position of massive power and influence. Use it wisely.