Extinction (Psychology)

In psychology, extinction refers to the gradual weakening and eventual disappearance of a learned behavior, a process observed in both operantly conditioned and classically conditioned behavior. When an operant behavior that had previously been reinforced stops producing any reinforcing consequence, its frequency gradually falls back toward the level it held before the behavior was learned, as when a child who misbehaves for attention stops misbehaving once the misbehavior no longer draws any attention at all. In classical conditioning, extinction occurs when a conditioned stimulus is repeatedly presented without the unconditioned stimulus it once predicted, as when Ivan Pavlov's dog gradually stopped salivating to the sound of a metronome once the metronome had been sounded many times with no food to follow; some anxiety disorders, including post-traumatic stress disorder, are believed to reflect at least in part a failure of this same extinction process to eliminate a conditioned fear.