Operant conditioning is learning in which behavior is strengthened or weakened by its consequences. Actions followed by reinforcement become more probable; actions followed by punishment become less probable.

The approach was developed systematically by B.F. Skinner, building on Thorndike’s law of effect. Reinforcement may be positive (adding a desirable stimulus) or negative (removing an aversive stimulus). Punishment may involve adding an aversive stimulus or removing a desirable one. Schedules of reinforcement—continuous or intermittent, fixed or variable, ratio or interval—powerfully influence the rate and persistence of behavior.

Operant principles explain a wide range of human and animal behavior, from simple habits to complex skills. They are applied in education, behavior therapy, animal training, and organizational management. Unlike classical conditioning, which links two stimuli, operant conditioning links an organism’s own actions with the outcomes those actions produce.

Behavior that works is repeated. Behavior that does not work fades. That is the core of operant conditioning.