Superstitions arise as the result of the spurious identification of patterns. Even pigeons are superstitious. In an experiment where food is delivered randomly, pigeons will note what they were doing when the pellet arrived, such as twirling to the left and then pecking a button, and perform the maneuver over and over until the next pellet arrives. A pigeon rain dance. The behavior is not much different than in the case of a baseball player who forgets to shave one morning, hits a home run a few hours later and then makes it a policy never to shave on game days.

Beliefs...