If food is presented to a hungry pigeon regularly at short intervals, the pigeon develops "conditioned" behavior because of accidental contingencies between response and reinforcement. In other words, the pigeon seems to behave as if the response were producing the food. When such a response (which might be termed "superstitious" has once appeared, the interval of presentation may be lengthened. The behavior continues at a high rate but may suffer a slow topographical change.