In operant conditioning
is an immediate increase in the strength of a response following a change in environment. Response strength can be assessed by measures such as the frequency with which the response is made (for example, a pigeon may peck a key more times in the session), or the speed with which it is made (for example, a rat may run a maze faster). The environment change contingent upon the response is called a reinforcer
. Reinforcement can only be confirmed retrospectively, as objects, items, food or other potential 'reinforcers' can only be called such by demonstrating increases in behavior after their administration. It is the strength of the response that is reinforced, not the organism.
Types of reinforcement
, the researcher who articulated the major theoretical constructs of reinforcement and behaviorism
, refused to specify causal origins of reinforcers. Skinner argued that reinforcers are defined by a change in response strength (that is, functionally rather than causally), and that what is a reinforcer to one person may not be to another. Accordingly, activities, foods or items which are generally considered pleasant or enjoyable may not necessarily be reinforcing; they can only be considered so if the behavior that immediately precedes the potential reinforcer increases in similar future situations. If a child receives a cookie when he or she asks for one, and the frequency of 'cookie-requesting behavior' increases, the cookie can be seen as reinforcing 'cookie-requesting behavior'. If however, cookie-requesting behavior does not increase, the cookie cannot be considered reinforcing. The sole criterion which can determine if an item, activity or food is reinforcing is the change in the probability of a behavior after the administration of a potential reinforcer. Other theories may focus on additional factors such as whether the person expected the strategy to work at some point, but a behavioral theory of reinforcement would focus specifically upon the probability of the behavior.
The study of reinforcement has produced an enormous body of reproducible experimental results. Reinforcement is the central concept and procedure in the experimental analysis of behavior and much of quantitative analysis of behavior.
- Positive reinforcement is an increase in the future frequency of a behavior due to the addition of a stimulus immediately following a response. Giving (or adding) food to a dog contingent on its sitting is an example of positive reinforcement (if this results in an increase in the future behavior of the dog sitting).
- Negative reinforcement is an increase in the future frequency of a behavior when the consequence is the removal of an aversive stimulus. Turning off (or removing) an annoying song when a child asks their parent is an example of negative reinforcement (if this results in an increase in asking behavior of the child in the future).
- Avoidance conditioning is a form of negative reinforcement that occurs when a behavior prevents an aversive stimulus from starting or being applied.
Skinner discusses that while it may appear so, Punishment is not the opposite of reinforcement. Rather, it has some other effects as well as decreasing undesired behavior.