B. F. Skinner emphasized the importance of making psychology a science, using controlled experiments to objectively measure behavior influencing cognitive psychology. Skinner believed that each person is born in a blank slate form. Skinner contributed the theory of operant conditioning; for example reinforcement strengthens behavior and punishment weakens behavior. Skinner developed this theory by conducting experiments on rats and pigeons in a “Skinner Box”. The theory of operant conditioning showed how the environment affects a person’s behavior. A dog trainer would use positive reinforcement to strengthen behavior by giving a dog a treat as recognition for a successful trick, but would use punishment to weaken behavior by placing that same dog outside when it jumps on the couch. However, the biological approach disapproves of Skinner’s theory as he does not demonstrate how hormones and chromosomes affect behavior. For example, testosterone makes a person more hostile.
One of Skinner's experiments examined the formation of superstition in the pigeon. Skinner placed a pigeon in a cage which had a food hopper attached to it. The food hopper would deliver food to the pigeon whenever Skinner placed food in it. What he discovered is that the pigeon associated the delivery of food with whatever actions it had been performing at the time the food was released from the hopper, and that the pigeon continued to perform these same actions whenever it wanted food. The experiment was believed to demonstrate a sort of superstition. The bird behaves as if there were a causal relation between its behavior and the presentation of food, although such a relation was lacking.