Skinner expanded on Thorndike's law of effect through experiments using operant chambers. He studied how behaviors are strengthened or weakened through reinforcement and punishment. Operant conditioning uses reinforcement to shape behaviors through successive approximations. Reinforcers can be primary, conditioned, immediate, or delayed. Reinforcement schedules include continuous, partial, fixed-ratio, variable-ratio, fixed-interval, and variable-interval. Punishment typically has negative side effects and provides no information to change behavior.

1. Operant Conditioning
Module 18

2. 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 University Library

3. 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.
Edition by Michael P. Domjan, 2005. Used with permission
From The Essentials of Conditioning and Learning, 3rd
by Thomson Learning, Wadsworth Division
Walter Dawn/ Photo Researchers, Inc.

4. 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.

5. Shaping
Shaping is the operant conditioning procedure
in which reinforcers guide behavior towards the
desired target behavior through successive
approximations.

6. 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/ Corbis

7. Primary & Secondary Reinforcers
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.

8. Immediate & Delayed 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.
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.

9. 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.

10. 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.)

11. 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.)

12. Punishment
An aversive event that decreases the behavior it
follows.

13. Punishment
Although there may be some justification for
occasional punishment (Larzelaere &
Baumrind, 2002), it usually leads to negative effects.
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.

14. Positive Reinforcement
• Behavior or response increases when
followed by the addition of a reinforcing
stimulus
– Examples:
• Dog treats
• Teacher’s praise
• Good grades = money

15. 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

16. 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.

17. 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

18. 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

19. Reinforcement and Punishment
Behavior Increases Decreases
Stimulus
Addition Positive Positive
Reinforcement Punishment
Removed Negative Negative
Reinforcement Punishment

20. 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?

21. Positive Reinforcement

22. 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?

23. Negative Reinforcement

24. 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?

25. Negative Punishment

26. 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?

27. Positive Punishment

28. Operant Conditioning
Worksheet

29. 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.

30. 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

31. 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

32. Applications of Operant
Conditioning
Reinforcers affect productivity. Many companies
now allow employees to share profits and
participate in company ownership.
At work

33. Applications of Operant
Conditioning
At Home
In children, reinforcing good behavior increases
the occurrence of these behaviors. Ignoring
unwanted behavior decreases their occurrence.