Classical conditioning forms associations between stimuli and involves respondent behavior, or the automatic responses to a stimulus. In operant conditioning, organisms associate their own actions with consequences. Action followed by reinforcers increase and those followed by punishers decrease. It uses operant behavior, or behavior that operates on the environment to produce rewarding or punishing stimuli.
Operant conditioning involves operant behavior that actively operates on the environment to produce stimuli. Skinner's work elaborated a simple fact that Edward Thorndike called the law of effect: rewarded behavior is likely to recur. In his experiments involving the now famous ‘Skinner box’, Skinner used shaping, a procedure in which rewards guide an animal's behavior toward a desired behavior. By rewarding responses that are ever closer to the final desired behavior, and ignoring all other responses, researchers can gradually shape complex behaviors.
A reinforcer is any event that increases the frequency of a preceding response. Reinforcers can be: positive, presenting a pleasant stimulus after a response; negative, reducing or removing an unpleasant stimulus; primary, innately satisfying; or secondary, learned; and immediate or delayed. When the desired response is reinforced every time it occurs, continuous reinforcement is involved. More common are partial reinforcement schedules. Fixed-ratio schedules reinforce behavior after a set number of responses; variable-ratio schedules provide reinforcers after an unpredictable number of responses. Fixed-interval schedules feature an equal pause after each reinforcer, and variable-interval schedules reinforce the first response after varying time intervals.
Like reinforcement, punishment is most effective when strong, immediate, and consistent. However, punishment is not simply the opposite of reinforcement, due to the fact that it can have several undesirable side effects, such as increased aggression...