II. Operant Conditioning

A. Definition

1. Learning in which a certain action is reinforced or punished, resulting in correspondence increases or decreases in occurrence

2. Learning from the consequences of behavior

3. The word operant is used because the subject operates on or causes some change in the environment

B. E.L. Thorndike & the Law of Effect

1. Edward Thorndike used animals (cats) to test his theories about learning– Developed one of the few laws in psychological

science.– Law of Effect deals with consequences of

behavior:

• Behavior that is reinforced is encouraged.

• Behavior that is punished is discouraged

2. Cats were to pull a lever to open the box– food was placed on the outside of the box

Thorndike’s Puzzle Box

C. B.F. Skinner1. Refined Thorndike’s Law of Effect

– Worked mainly with pigeons, rats– Believed all behavior was governed by

consequences.

2. Developed the fundamental principles and techniques of operant conditioning.

3. Devised ways to apply these principles in the real world.

4. Designed the Skinner Box (programmed to deliver rewards based on animal’s behavior)

– Built & raised his only daughter in a modified “Skinner Box”

D. Reinforcement v. Punishment

1. Reinforcement - Any consequence that increases the likelihood of the behavior to be repeated. 2. Punishment - Any consequence that decreases the likelihood of the behavior to be repeated.

E. Punishment

1. Most effective if it is delivered immediately after the unwanted behavior and if it is harsh

2. Harsh punishment may also result in unwanted consequences (fear & anger)

3. Two types of learning that have to do with punishment:

– Escape learning: allows one to terminate an unappealing stimulus (Sammy creates a ruckus in the English class he hates & is asked to leave)

– Avoidance learning: enables one to avoid the unpleasant stimulus altogether (Sammy cuts the English class)

Reinforcement

Punishment

GOAL: to make/continue behavior

GOAL: to STOP behavior

Positive Reinforceme

nt

Negative Reinforceme

nt

Positive Punishment

Negative Punishment

Add (+) something

good

Take away (-) something bad

Add (+) something bad

Take away (-) something

good

EX: Giving candy for good

behavior

EX: Relieving headaches after taking Tylenol™

EX: Spanking for bad

behavior

EX: Going to “time-out” for 5

minutes for bad behavior

F. Types of Reinforcers

1. Primary reinforcers–Items that are naturally reinforcing.

–EX: Food, shelter, water

2. Secondary reinforcers–Items whose value must be

learned.

–EX: Money, grades

G. Schedules of Reinforcement

1. Punishers & reinforcers can be administered by: – Continuous schedule (behavior is reinforced

every single time)• Punishers are most effective when this is used

– Partial schedule (responses are generally more stable and last longer once they are learned)

• Reinforcement is more effective when this is implemented

H. Types of Partial Schedules1. Fixed-Ratio

– Specified number of correct responses before reinforcement is provided.

• Being paid for every 10 pizzas made.• Being ejected from a basketball game after five fouls.

2. Fixed-Interval– Reinforcement of first response after a fixed amount of time has

passed.• Cramming for an exam.• Picking up your check from your part-time job.

3. Variable-Ratio– Unpredictable number of responses are required before

reinforcement is provided.• Playing a slot machine• Sales commissions

4. Variable-Interval– Reinforcement of first response after varying amount of time.

• Pop quizzes in class.• Dialing a friend on the phone and getting a busy signal.

I. Applications of Operant Conditioning1. Shaping: reinforcing for behaviors that are similar

or that lead to the desired behavior

• Helps avoid superstitious behavior

2. Chaining: taught to perform a number of responses successively in order to get a reward

• Example: A rat learned to run through a obstacle course in order to obtain a food reward

3. Behavior modification- uses reinforcement & punishment to reduce inappropriate behaviors & to increase engagement in appropriate behaviors

– Token economies: an individual is given tokens (have no true value) after performing a desired behavior

• Trade in tokens for any type of reinforcers• Often used in prisons, mental institutions, & schools