Behavioral Approach
B.F. Skinner
ICSP254 Theories of Personality
B.F. Skinner
• “It is the environment which must be changed” – B.F. Skinner
Introduction
• Skinner contended that psychology is the science of behavior
of an organism.
• Other theorists look inside the person for causes, motives, and
drives that originated within us. Skinner, in contrast, made no
reference to internal states that account for behavior.
• Unconscious, defense mechanisms, traits, etc. cannot be
seen – therefore – have no place in scientific psychology
• Human beings are “empty organisms” meaning that there is
nothing inside us that can explain behavior in scientific terms
Introduction
• His choice of experimental subjects differ greatly from other
theorists, using rats and pigeons
• What can we learn from pigeons about human personality?
• Animals show simpler behavioral response to stimuli, so it’s
easier to study them and extrapolate to humans (which simply
have different intensity of responses)
Theory of Operant Conditioning
• We learn as a result of reward or punishment
• Thorndike’s Law of Effect – behaviors are initially emitted at
random, in a trial and error fashion. These random behaviors
are followed by pleasurable consequences (reward) become
stronger. Those followed by unpleasant consequences
(punishment) become weaker and less frequent
Agenda
Reinforcement and Punishment
Schedules of Reinforcement
Rates and Pattern of Responding
Other Key Concepts
Reinforcement and Punishment
• Reinforcement – to increase the target behavior. It brings
subject into a more desirable state
• Punishment – to decrease the target behavior. It brings
subject into a less desirable state
Reinforcement and Punishment
• Reinforcement and Punishment can be either positive or
negative
• Positive – something is “added”
• Negative – something is “subtracted”
There are 4 possible combinations:
Positive reinforcement, negative reinforcement
Positive punishment, negative punishment
Positive Reinforcement
• Positive = something is “added”
• Reinforcement = to increase the target behavior. It brings subject
into a more desirable state
• Putting both together, positive reinforcement is when something is
added to increase behavior, a.k.a., reward
• After target behavior is performed, something of value is given to
the person. It is reinforcement because it increases the target
behavior.
• Ex. A child is given a sticker after she makes her bed. Something is
added (sticker) that makes the child more likely to make her bed
(target behavior)
Negative Reinforcement
• Negative = something is “subtracted” or taken away
• Reinforcement = to increase target behavior
• Negative reinforcement is relief.
• Ex. You get a headache. You take a Tylenol (target behavior)
and then headache goes away (something is subtracted).
You’re more likely to take Tylenol in the future when you have
another headache (increase target behavior)
Positive Punishment
• Positive = something is “added”
• Punishment = to decrease target behavior
• Positive punishment is pain
• Ex. The child jumps on the couch (target behavior) and then
get hit by the mom (something is added, pain). The child is
less likely to jump on the couch in the future.
Negative Punishment
• Negative = something is “subtracted”
• Punishment = to decrease target behavior
• Negative punishment is loss
• Ex. A child hit her sibling (target behavior) and got her tablet
taken away by the parent (something is subtracted). Child is
less likely to hit sibling (decrease target behavior) in the future.
Tips
• Think of Positive (+) and Negative (-) as mathematical signs to
remember that something is “added” or “subtracted”
• Ask yourself “what is the target behavior?”
• What happen after target behavior is performed? (is
something added or subtracted?)
• Is subject more or less likely to do target behavior in the
future?
Example 1
• A child did not get the toy that he wanted. He then started
yelling loudly in the department store. The mother scolds the
child and the child quiets down.
• What type of contingency is controlling child’s behavior?
First, what is the target behavior?
Is something added or subtracted?
Is child more or less likely to perform target behavior in the
future?
Positive Punishment
1. Child’s target behavior is yelling
2. After child yell, mother scolded him (something is added) –
positive
3. After being scolded, child is probably going to yell less in the
future (to decrease target behavior – punishment
Example 2
• A child did not get the toy that he wanted. He then started
yelling loudly in the department store. The mother scolds the
child and the child quiets down.
• What type of contingency is controlling mother’s behavior?
First, what is the target behavior?
Is something added or subtracted?
Is child more or less likely to perform target behavior in the
future?
Negative Reinforcement
1. Mother’s target behavior is scolding
2. When mother performed target behavior, child quiets down
(something is subtracted) – negative
3. Mother is more likely to increase target behavior (scolding)
in the future – reinforcement
Agenda
Reinforcement and Punishment
Schedules of Reinforcement
Rates and Pattern of Responding
Other Key Concepts
Schedules of Reinforcement
• Teaching of new behaviors generally accomplished through
reinforcement rather than punishment
• Acquisition phase – period during which new learning occurs
• Extinction phase – period in which reinforcement is withheld
• Operant strength – strengths of behavior measured by rate of
responding (i.e., how often do the pigeons peck) during both
acquisition and extinction phase.
Types of Reinforcement
Continuous
Intermittent
Continuous Reinforcement
• Reinforcing every occurrence of behavior
• Best for acquiring new behavior
• But highly susceptible to satiation and extinction
• Satiation – reinforcer losing its value through overuse
• To resolve this issue, after acquisition phase, schedule of
reinforcement is best changed from continuous to
intermittent, a change termed thinning
Intermittent Reinforcement
• Subject is not reinforced for every occurrence of behavior
fixed
interval
(of time)
Reinforcement to Actual Behaviors
Variable
Ratio
Fixed Interval (FI)
• Reinforcement occurs the first time target behavior is emitted
after the fixed time interval elapsed
• Ex. Child taken to Swensens for ice cream if she completes her
homework (target behavior) provided at least one week has
passed (fixed interval) since she was last reinforced
• Response rate is usually low during most of the interval and
increase significantly at the end of the interval
Variable Interval (VI)
• Reinforcement occurs the first time target behavior is emitted
after a variable, unpredictable interval of time elapsed.
• Ex. Pigeon receive feed if they peck once at end of 20
seconds interval, then at 30 seconds, then after 40 seconds
• Response rate: Here, subject can’t anticipate when
reinforcement might occur and therefore continue to perform
behavior at moderate rate and without pause
Fixed Ratio (FR)
• Reinforcement occurs after contain, unchanging number of
responses are emitted.
• Ex. You get to eat chocolate after every 500 push ups.
• Response rate is typically moderate to high, and subject may
pause after reinforcement is provided, especially if the ratio is
large (i.e., many responses are required before
reinforcement)
Variable Ratio (VR)
• Reinforcement occurs after an unpredictable number of
responses are emitted.
• Ex. Slot machine, one cannot predict how many times of
playing required to win money (reinforcement)
• Response rate is high (subject continuing to perform the
behavior) and with little pause
Agenda
Reinforcement and Punishment
Schedules of Reinforcement
Rates and Pattern of Responding
Other Key Concepts
Rates of Responding
Variable
Ratio
During Acquisition:
Fixed
Ratio
Variable
Interval
Fixed
Interval
Memory Aid
• To help you remember schedules, keep in mind first that
linking reinforcement to actual behavior (i.e., ratio) is stronger
than linking it to passage of time (i.e., interval)
• Next, remember that unpredictability (i.e., variable) keeps the
subject guessing and trying harder than predictability (i.e.,
fixed)
Resistance to Extinction
Variable
Ratio
• During Extinction:
• Follows exactly same pattern
where variable ratio (VR) is
the most resistant to
extinction
• Behaviors learned through
fixed interval (FI) extinguished
most easily and quickly
Fixed
Ratio
Variable
Interval
Fixed
Interval
Pattern of Responding
Fixed schedules result
in pauses after
reinforcement
(scalloped patterns)
Fixed interval (FI)
appears most
scalloped
Variable schedules
result in more
uninterrupted
behaviors
To Summarize
• New learning occur best with continuous reinforcement
• To maintain behavior, reinforcement should be thinning out to
intermittent schedule
• Of the schedules, variable ratio (VR) results in greatest rates of
responding during acquisition and greatest resistance to
extinction
Agenda
Reinforcement and Punishment
Schedules of Reinforcement
Rates and Pattern of Responding
Other Key Concepts
Operant Extinction
• Operant extinction results from stopping to reinforce behaviors
that has previously been reinforced
• At first, withholding reinforcement will usually result in an
increase in behavior. Why?
• Response burst – increase in behavior after reinforcement first
withheld
• Overtime, unreinforced behaviors will be extinguished
Superstitious Behavior
• Superstitious behavior results from accidental reinforcement or
from non-contingent reinforcement
• Ex. you have a “lucky” necklace. Last time you happen to
wear this necklace, you won the lottery. You somehow
assumed that it was the necklace that gave you the luck.
Thus, you came to believe in the “lucky” necklace and wear it
everyday.
Discrimination Learning
• Target behaviors are reinforced in certain circumstances, but
not in others
• Subject learns to “discriminate” between those situations in
which reinforcement will be coming and those in which it will
not.
• The stimulus that signals reinforcement will take place is known
as the discriminative stimulus
• The stimulus that signals reinforcement will not take place is
known as the S delta
Discrimination Learning (2)
• Ex. Pigeon pecks the bar when the light is green (discriminative
stimulus) because it learned that he will be reinforced. He does
not peck when the light is red (S Delta) because there is no
reinforcement when light is red
• Ex. A child only whines to grandmother because she will pay
attention but he does not whine around his mom who ignores
whining behavior. Here, the grandmother serves as
discriminative stimulus while mom serves as S delta.
Stimulus Generalization
• Stimulus generalization – occurs when a subject begins to emit
the target behavior in the presence of stimuli similar to but not
exactly the same as the discriminating stimulus
• Ex. Pigeon gets food when it pecks at green light might also
peck at blue light, expecting reinforcement
• Ex. Child who gets attention when he whines in front of
grandmother may also whine in presence of other older
woman, expecting reinforcement
Response Generalization
• Response generalization – performing behavior that is similar
but not identical to the one that has previously been
reinforced.
• Ex. A dog sits and get reinforced with biscuit. Later, the dog lie
down on the ground (similar but not identical behavior)
hoping to get a biscuit also.
Stimulus vs. Response Generalization
• You have to decide what’s changing: the stimulus or the
response
• Ex. Child’s behavior of whining is the same, but stimulus to
which he does has changed (grandmother to elderly), hence
it is stimulus generalization
• Ex. When the dog changed behavior, his response has
changed, hence it is response generalization
Shaping
• Shaping – teaching a subject to emit a desired behavior by
providing reinforcement as the person gets closer and closer
to the desired behavior
• In other words, subject is reinforced for behaviors that
“approximate” the desired behavior
• Ex. Teaching an autistic child to say own name
Premack Principle
• Also known as “Grandma’s rule”
• Premack principle – a high frequency behavior (i.e.,
something a person likes to do) is used to reinforce a low
frequency behavior
• Ex. If you eat your spinach (low frequency behavior), you can
go out to play (high frequency behavior)
Behavioral Contrast
• A situation where two behaviors have been equally enforced,
then only one behavior is reinforced. Typically, the behavior
that is being reinforced increases in frequency while the
behavior that is no longer being reinforced decreases.
Questions about Human Nature
Past
Present
Free Will
Determinism
Nature
Nurture
• Past or Present?
Childhood experiences more important
because our basic behaviors are learned in
childhood
• Free Will or Determinism?
People functioned like machines, in an
orderly predetermined way. Behaviors
controlled by reinforcer.
• Nature or Nurture?
People are products of learning (nurture)
Questions about Human Nature
Uniqueness
Universality
Equilibrium
Growth
• Unique or Universal?
Each person is unique because we are
shaped (learned) by diff experiences
• Equilibrium or Growth?
Equilibrium
• Optimism or Pessimism?
Optimism
Pessimism
Pessimistic conception of people as
helpless and passive robots