OPERANT CONDITIONINGChanging Behavior Through Reinforcement and Punishment

OPERANT CONDITIONING

• Learning Objectives:1. Outline the principles of operant conditioning.2. Explain how learning can be shaped through the use of reinforcement schedules

and secondary reinforcers.

OPERANT CONDITIONING

• Operant Conditioning– learning based on the consequences of behavior– may involve the learning of new behaviors

HOW REINFORCEMENT AND PUNISHMENT INFLUENCE BEHAVIOR

• Edward L. Thorndike– First scientist to systematically

study operant conditioning– Observed cats trying to escape

from puzzle boxes– Developed law of effect:

• Responses that produce a pleasant outcome are likely to be repeated in a similar situation.

• Responses that produce an unpleasant outcome are less likely to be repeated in a similar situation.

• B. F. Skinner– Expanded on Thorndike’s ideas to

develop a more complete set of principles to explain operant conditioning

– Created specially designed environments called operant chambers or Skinner boxes to study learning systematically

HOW REINFORCEMENT AND PUNISHMENT INFLUENCE BEHAVIOR

• Operant chamber or “Skinner box”– Cage large enough for a rodent or

bird– Contains a bar or key that the

organism can press or peck to release food or water

– Contains a device to record the animal’s responses

HOW REINFORCEMENT AND PUNISHMENT INFLUENCE BEHAVIOR

HOW REINFORCEMENT AND PUNISHMENT INFLUENCE BEHAVIOR

• Positive reinforcement is a more effective way to change behavior than is punishment– Punishment creates only a temporary change in behavior.– Punishment creates a negative and adversarial relationship with the individual

providing the punishment.

CREATING COMPLEX BEHAVIORS THROUGH OPERANT CONDITIONING

• Continuous reinforcement– A response is reinforced each

time it occurs.• example: Each time a

dog rolls over, it receives a biscuit.

– Leads to rapid initial learning, but also to poor resistance to extinction

• Partial (or intermittent) reinforcement– A response is sometimes

reinforced, sometimes not.• example: When you hold

a door for someone, sometimes you are reinforced with a smile or a “thank you,” but sometimes you aren’t,

– Leads to slower initial learning, but also to greater resistance to extinction

CREATING COMPLEX BEHAVIORS THROUGH OPERANT CONDITIONING

CREATING COMPLEX BEHAVIORS THROUGH OPERANT CONDITIONING

• Schedules based on the number of responses (ratio types) induce greater response rate than do schedules based on elapsed time (interval types).

• Also, unpredictable schedules (variable types) produce stronger responses than do predictable schedules (fixed types).

CREATING COMPLEX BEHAVIORS THROUGH OPERANT CONDITIONING

• Shaping– Process of guiding an organism’s behavior to the desired outcome through the

use of successive approximations to a final desired behavior• allows the creation of complex behaviors

CREATING COMPLEX BEHAVIORS THROUGH OPERANT CONDITIONING

• Primary reinforcers– Stimuli that are naturally

preferred by the organism• examples include food,

water, relief from pain

• Secondary reinforcers– Neutral event that has

become associated with a primary reinforcer through classical conditioning• one example is money

OPERANT CONDITIONING

• Key Takeaways– Edward Thorndike developed the law of effect: the principle that responses that

create a pleasant outcome in a particular situation are more likely to occur again in a similar situation, whereas responses that produce an unpleasant outcome are less likely to occur again.

– B. F. Skinner expanded on Thorndike’s ideas to develop a set of principles to explain operant conditioning.

– Positive reinforcement strengthens a response by presenting something pleasant after the response, whereas negative reinforcement strengthens a response by reducing or removing something unpleasant.

OPERANT CONDITIONING

• Key Takeaways, continued– Positive punishment weakens a response by presenting something unpleasant

after the response, whereas negative punishment weakens a response by reducing or removing something pleasant.

– Reinforcement may be either partial or continuous. Partial reinforcement schedules are determined by whether the reinforcement is presented on the basis of the time that elapses between reinforcements (interval) or on the basis of the number of responses that the organism engages in (ratio), and by whether the reinforcement occurs on a regular (fixed) or unpredictable (variable) schedule.

– Complex behaviors may be created through shaping, the process of guiding an organism’s behavior to the desired outcome through the use of successive approximation to a final desired behavior.