Psychology Chapter 9

Psychology Chapter 9
Section 4: Principles of
Operant Conditioning
The “Skinner Box”
• When a rat in a
Skinner box presses
a bar, a food pellet
or drop of water is
• Similar boxes exist
for pigeons & many
other species.
Wade and Tavris © 2005
Prentice Hall
• Extinction- procedure that causes a
previously learned response to stop
–Occurs when the reinforcer that
maintained the response is
removed or is no longer available
Stimulus Generalization & Discrimination
• Generalization occurs when responses
generalize to the stimulus that were not
present during the original learning situation
but resemble that original stimulus
• Sometimes a human or animal learns to
respond to a stimulus only when a
discriminative stimulus is present
• The discriminative stimulus
signals whether a response, if
made, will pay off
• Traffic lights, doorbells, ringing
phone, etc
Learning on Schedule
• Continuous Reinforcement:
–A reinforcement schedule in which a
particular response is always reinforced.
• Intermittent (Partial) Schedule of
–A reinforcement schedule in which a
particular response is sometimes but not
always reinforced.
–Explains why people get attached to “lucky”
hats, etc
• Patterns of reinforcement affect the rate,
form, & timing of behavior
• If you want a response to persist after it has
been learned, you should reinforce it
intermittently, not continuously
• If you are going to extinguish an undesirable
behavior by ignoring it, you must be
consistent in with holding reinforcement
• Shaping
–For a response to be reinforced, it must first
–You start by reinforcing a tendency in the
right direction & then you gradually require
responses that are more similar to the final,
desired response
–Successive approximations
–Animal training- seeing eye dogs
Biological Limits on Learning
• Operant conditioning always works best
when they capitalize on inborn
• Beware of instinctive drift
• Humans can be affected by biology,
genetics, & the evolutionary history of
our species
Skinner: The Man and the Myth
• Burrhus Frederick Skinner,
– Better known as B.F.
• Much misinformation is
circulated about his life &
– e.g., his daughters grew up
normal, despite rumors
that they were