Subjects were asked to complete a bogus personality test. The experimenter then gave them all exactly the same sketch of their personalities, which he claimed was based on their test results. When asked about the accuracy of the sketch, 90 per cent of the subjects thought it a very good or excellent description of themselves. People are so good at distorting material to fit their expectations that the identical sketch was thought by each of nearly fifty subjects to apply specifically to him or her.
In addition to trying unconsciously to confirm his or her beliefs, anyone who pays to see a fortune teller will have invested time and money: unless he has just gone for a lark, he will therefore want to feel he has got something out of it (misplaced consistency) and hence will be predisposed to believe what he hears.
Excerpt from: Irrationality: The enemy within by Stuart Sutherland