Reinforcement and punishment are the core tools through which operant behavior is modified. These terms are defined by their effect on behavior. Either may be positive or negative.
- Positive reinforcement and negative reinforcement increase the probability of a behavior that they follow, while positive punishment and negative punishment reduce the probability of behaviour that they follow.
Another procedure is called “extinction”.
- Extinction occurs when a previously reinforced behavior is no longer reinforced with either positive or negative reinforcement. During extinction the behavior becomes less probable. Occasional reinforcement can lead to an even longer delay before behavior extinction due to the learning factor of repeated instances becoming necessary to get reinforcement, when compared with reinforcement being given at each opportunity before extinction.
There are a total of five consequences.
- Positive reinforcement occurs when a behavior (response) is rewarding or the behavior is followed by another stimulus that is rewarding, increasing the frequency of that behavior. For example, if a rat in a Skinner box gets food when it presses a lever, its rate of pressing will go up. This procedure is usually called simply reinforcement.
- Negative reinforcement (a.k.a. escape) occurs when a behavior (response) is followed by the removal of an aversive stimulus, thereby increasing the original behavior’s frequency. In the Skinner Box experiment, the aversive stimulus might be a loud noise continuously inside the box; negative reinforcement would happen when the rat presses a lever to turn off the noise.
- Positive punishment (also referred to as “punishment by contingent stimulation”) occurs when a behavior (response) is followed by an aversive stimulus. Example: pain from a spanking, which would often result in a decrease in that behavior. Positive punishment is a confusing term, so the procedure is usually referred to as “punishment”.
- Negative punishment (penalty) (also called “punishment by contingent withdrawal”) occurs when a behavior (response) is followed by the removal of a stimulus. Example: taking away a child’s toy following an undesired behavior by him/her, which would result in a decrease in the undesirable behavior.
- Extinction occurs when a behavior (response) that had previously been reinforced is no longer effective. Example: a rat is first given food many times for pressing a lever, until the experimenter no longer gives out food as a reward. The rat would typically press the lever less often and then stop. The lever pressing would then be said to be “extinguished.”
It is important to note that actors (e.g. a rat) are not spoken of as being reinforced, punished, or extinguished; it is the actions that are reinforced, punished, or extinguished. Reinforcement, punishment, and extinction are not terms whose use is restricted to the laboratory. Naturally-occurring consequences can also reinforce, punish, or extinguish behavior and are not always planned or delivered on purpose.