Chapter 4: Reinforcement
•Reinforcement is the process in which a behavior is strengthened by the immediate consequence
that reliably follows its occurrence.
•When a behavior is strengthened, it is more likely to occur again in the future.
•The earliest demonstration of reinforcement was reported by Thorndike in 1911, The law of effect.
•Thorndike placed a hungry cat in a cage and put food outside the cage where the cat could see it.
•He rigged the cage so that a door would open if the cat hit a lever with its paw.
•The cat was clawing and biting the bars of the cage, trying to get out of the cage.
•Eventually by accident the cat hit the lever, the door opened and the cat got out of the cage and ate
•When the hungry cat was put back into the cage, the cat was more likely to hit the lever because
this behavior had resulted in an immediate consequence: escaping the cage and getting food.
•Getting to the food was the consequence that reinforced (strengthened) the cat’s behavior of
hitting the lever with a paw.
•In the 1930’s, Skinner conducted numerous similar studies on the principle of reinforcement in
laboratory animals such as rats and pigeons.
•Reinforcement may occur naturally as a result of our day-to-day interactions with our social and
physical environment, or it may be planned as part of a behavior modification program used to
change a person’s behavior.
•Reinforcement is defined as:
•1. The occurrence of a particular behavior
•2. Is followed by an immediate consequence.
•3. That results in strengthening the behavior. (The person is more likely to engage in the
behavior again in the future).
• A behavior strengthened through the process of reinforcement is called an operant behavior. An
operant behavior acts on the environment to produce a consequence and, in turn, is controlled by, or
occurs again in the future as a result of, its immediate consequence.