Ever knock on wood, cross your fingers, or carry around a lucky charm? If you have done one of these it's likely that you are superstitious, other wise you probably know someone who believes in superstition. As it turns out though, humans aren't the only ones prone to superstition; psychologist B.F Skinner performed a study where food deprived pigeons showed superstitious behavior.
In his study the pigeons were put in a Skinner box where food was delivered as reinforcement every 15 seconds no matter what the pigeons did. As the study continued Skinner observed the pigeons having strange behavior. Some birds did a couple of turns between reinforcements; others would thrust their head into the upper corners of the cage. The pigeons acted this way because they thought that there was a connection between their behavior and the reinforcements. However there was absolutely no connection since the reinforcements would come regardless of what the pigeons were doing. Since the pigeons didn't know this though, the reinforcements strengthened each time it worked.
This became known as superstitious conditioning, even though it is actually accidental operant conditioning. I find this idea about superstition extremely interesting, especially since I am a big believer in knocking on wood and many other superstitions. I always knew that knocking on wood probably would do absolutely nothing, yet I still always did it. I think that superstition falls in the same realm as ESP, apophenia, and pareidolia. As humans we sometimes need a little extra assurance or ways to explain why things are the way they are.