Operant Conditioning

Module 18

Skinner’s Experiments

Skinner’s experiments extend Thorndike’s thinking, especially his law of effect. This law states that rewarded

behavior is likely to occur again.

Yale U

niversity Library

Operant Chamber

Using Thorndike's law of effect as a starting point, Skinner developed the

Operant chamber, or the Skinner box, to study operant conditioning.

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Operant Chamber

The operant chamber, or

Skinner box, comes with a bar or key

that an animal manipulates to

obtain a reinforcer like food or water. The bar or key is

connected to devices that record

the animal’s response.

Shaping

Shaping is the operant conditioning procedure in which reinforcers guide behavior towards the desired target

behavior through successive approximations.

Types of Reinforcers

Reinforcement: Any event that strengthens the behavior it follows. A

heat lamp positively reinforces a meerkat’s behavior in the cold.

Reuters/ C

orbis

1. Primary Reinforcer: An innately reinforcing stimulus like food or drink.

2. Conditioned Reinforcer: A learned reinforcer that gets its reinforcing power through association with the primary reinforcer.

Primary & Secondary Reinforcers

1. Immediate Reinforcer: A reinforcer that occurs instantly after a behavior. A rat gets a food pellet for a bar press.

2. Delayed Reinforcer: A reinforcer that is delayed in time for a certain behavior. A paycheck that comes at the end of a week.

Immediate & Delayed Reinforcers

We may be inclined to engage in small immediate reinforcers (watching TV) rather than large

delayed reinforcers (getting an A in a course) which require consistent study.

Reinforcement Schedules

1. Continuous Reinforcement: Reinforces the desired response each time it occurs.

2. Partial Reinforcement: Reinforces a response only part of the time. Though this results in slower acquisition in the beginning, it shows greater resistance to extinction later on.

Ratio Schedules

1. Fixed-ratio schedule: Reinforces a response only after a specified number of responses. e.g., piecework pay.

2. Variable-ratio schedule: Reinforces a response after an unpredictable number of responses. This is hard to extinguish because of the unpredictability. (e.g., behaviors like gambling, fishing.)

Interval Schedules

1. Fixed-interval schedule: Reinforces a response only after a specified time has elapsed. (e.g., preparing for an exam only when the exam draws close.)

2. Variable-interval schedule: Reinforces a response at unpredictable time intervals, which produces slow, steady responses. (e.g., pop quiz.)

Punishment

An aversive event that decreases the behavior it follows.

Punishment

1. Results in unwanted fears.2. Conveys no information to the organism.3. Justifies pain to others.4. Causes unwanted behaviors to reappear

in its absence.5. Causes aggression towards the agent.6. Causes one unwanted behavior to appear

in place of another.

Although there may be some justification for occasional punishment (Larzelaere &

Baumrind, 2002), it usually leads to negative effects.

Positive Reinforcement

• Behavior or response increases when followed by the addition of a reinforcing stimulus– Examples:

• Dog treats• Teacher’s praise• Good grades = money

Negative Reinforcement

• Behavior or response increases when followed by the removal, avoidance or escape of an unpleasant stimulus– Examples:

• Taking an aspirin• Crying = toy• Alarm clock

More examples – Negative Reinforcement

1. Taking aspirin to relieve a headache.

2. Hurrying home in the winter to get out of the cold.

3. Giving in to an argument or to a dog’s begging.

4. Fanning oneself to escape the heat.

5. Leaving a movie theater if the movie is bad.

6. Smoking in order to relieve anxiety.

7. Following prison rules in order to be released from

confinement.

8. Feigning a stomachache in order to avoid school.

9. Putting on a car safety belt to stop an irritating

buzz.

10. Turning down the volume of a very loud radio.

11. Putting up an umbrella to escape the rain.

12. Saying “uncle” to stop being beaten.

Positive Punishment

• Behavior or response decreases when followed by the addition or application of an aversive stimulus– Examples:

• Spanking• Bad behavior = more chores• Yelling at spouse

Negative Punishment

• Behavior or response decreases when followed by the removal of a reinforcing stimulus– Examples:

• Dude I’m grounded• Time-out• Driving drunk = loss of license

Reinforcement and Punishment

Behavior Stimulus

Increases

Decreases

Addition Positive Reinforcement

Positive Punishment

Removed Negative Reinforcement

Negative Punishment

Identify the Type of Conditioning

Tim is learning to play the trombone. His teacher notices that Tim likes baseball so she begins to give him a baseball card every time he successfully learns to play a new piece of music. How is Tim being conditioned?

Positive Reinforcement

Identify the Type of Conditioning

Anna ate something that upset her stomach. Anika suggested that she take a special mixture of peppermint tea and saltine crackers. Anna took the cure and felt much better. The next time Anna felt sick to her stomach, she fixed herself peppermint tea and crackers. How has Anna been conditioned?

Negative Reinforcement

Identify the Type of Conditioning

Fredrick refuses to take out the trash, so his mother refuses to allow him to watch his favorite TV show in the evening. How has Fredrick been conditioned?

Negative Punishment

Identify the Type of Conditioning

Jen was in a hurry to meet her friends for dinner. Jen is going 85 in a 65 and gets pulled over by a police officer. The officer gives her a ticket. How is Jen being conditioned?

Positive Punishment

Operant Conditioning Worksheet

Intrinsic Motivation

Intrinsic Motivation: The desire to perform a behavior for its own sake.

Extrinsic Motivation: The desire to perform a behavior due to promised rewards or threats of punishments.

Skinner’s Legacy

Skinner argued that behaviors were shaped by external influences instead of

inner thoughts and feelings. Critics argued that Skinner dehumanized people by

neglecting their free will.

Falk/ Photo Researchers, Inc.

Applications of Operant Conditioning

Skinner introduced the concept of teaching machines that shape learning in small steps and provide reinforcements

for correct rewards.

In School

LWA

-JDL

/ Corbis

Applications of Operant Conditioning

Reinforcers affect productivity. Many companies now allow employees to share

profits and participate in company ownership.

At work

Applications of Operant Conditioning

At Home

In children, reinforcing good behavior increases the occurrence of these

behaviors. Ignoring unwanted behavior decreases their occurrence.