It is surprising to discover how thoroughly our basic functions sometimes control our conscious minds. Scientific studies have shown that mice and pigeons, and recently other animals such as cuttlefish, can be taught to react to a specific arbitrary sign with a specific set of behaviors: animals learn to expect food at a sight or sound, and learn to receive food by manipulating a lever, ringing a bell, or pecking a certain spot. Through habituation, they are conditioned to consistently believe that specific phenomena or actions regularly lead to the same specific results.