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Chapter 7: Behavior and Its Consequences
W. J. Wilson, Psychology
November 7, 2016
Basic Tools and Issues Reinforcement versus contiguity theory
Flexibility, purpose, and motivation Operant psychology
Conditioned reinforcement The Relationship between Behavior and
Payoff Different ways to schedule payoff Choice Choice is
everywhere Impulsiveness and self-control Behavioral economics:
Are reinforcers all alike? Theories of Reinforcement Drive reduction
The Premack principle Problems with the Premack principle
Behavioral regulation theory Selection by consequences
Reinforcement or Contiguity?
• Thorndike (a reinforcement theorist):
• Law of effect: positive consequences strengthen responses;
negative consequences weaken responses
Reinforcement or Contiguity?
• Guthrie (a contiguity theorist):
• Reinforcement not necessary: S & R occur together and they
become associated.
• Learning requires only 1 trial
S-R v S-S Learning
• Thorndike & Guthrie: S-R
• Response is strengthened; no learning about anything
• MacFarlane (1930): Swimming rats disproved S-R.
• Tolman: S-S
• S is learned about; specific Rs are not learned
S-R v S-S Learning
• Tolman et al. (1946): Circuitous path
study
• Tolman et al. (1946): Plus-maze study
• Tolman & Honzik (1930): Reinf-NonReinf
Study
• – All illustrate that Rs not learned
• – T & H: Reinforcement unnecessary
Skinner’s Operant Psychology
• “Atheoretical” - focussed entirely on S & R; mind (and brain)
irrelevant to a science of behavior.
• Operants: Rs that operate on environment (& can be made
whenever the animal wants, hence they seem voluntary)
• Superstitious behaviors
• Stimulus control: SD and S∆
• Cumulative recorder
Schedules of Reinforcement
Continuous reinforcement: CRF
Partial reinforcement:
• Fixed Ratio (FR1 is special case: continuous reinforcement)
• Fixed Interval — scalloped cumulative record
• Varied Ratio — highest rate of responding
• Varied Interval — slow, steady rate
• others are possible: e.g., DRL
• Partial Reinforcement Effect
Choice
• Concurrent schedules allow examination of choice behavior
• Herrnstein (1961) Matching Law:
B1 /(B1 + B2 ) = R1 /(R1 + R2 )
(1)
• e.g., behavior occurs proportionally to the extent to which it
is reinforced.
• Choice is everywhere — even if only 1 behavior is being
measured, many others are always available to the subject.
Quantitative Law of Effect
Herrnstein (1970):
B1 = KxR1 /(R1 + RO )
(2)
• K: constant reflecting all possible behavior in a given situation
• RO : constant reflecting total reinforcement value of all other
behaviors.
• K & R will vary from animal to animal
• Bouton suggests implications for understanding attraction of
drugs to some people, especially those with low RO
Impulsiveness
• Animals (human and non-human) will select small soon
reward over large delayed reward
• If choice is made well in advance of the rewards, larger one is
usually chosen, even if it comes later.
• Rachlin suggests that “pre-commitment” can avoid impulsive
choice.
• Implications for behavior on “Deal or No Deal?”
Behavioral Economics
Are All Reinforcers alike?
• Tinklepaugh (1928): monkeys, banana, lettuce. Tells us about
substitutability, cognition.
• Reinforcers can be substitutes, independent, or complements.
• PCP cost goes up, alcohol substitutes
• Alcohol cost goes up, PCP independent!
• Alcohol cost goes up, cigarettes act as complements.
• An understanding of substitutability is necessary to an
understanding of reinforcement.
Theories of Reinforcement
Hull’s Drive Reduction
• Drive arises from need — shortage of a biological essential
• Drive reduction is reinforcing
• BUT: many reinforcers unrelated to need
Theories of Reinforcement
Premack Principle
• More-preferred R will reinforce a less-preferred R.
• Measure which of two Rs is more preferred, can safely predict
that it will reinforce the other one.
• Sometimes adequate or appropriate measure of preference is
difficult
Theories of Reinforcement
Behavior Regulation Theory (response deprivation hypothesis)
• Preferred level for every R
• If R is prevented to a point below its preferred level, animal
will engage in it more when given the opportunity.
• Result is that a “ledd-preferred” R, if prevented, will then
reinforce a more-preferred R.
• “Bliss point” illustrates preferred level of each of two Rs when
preference is measured.
• When sched of reinf constrains extent to which Rs can occur,
the level of each will achieve the “minimum distance” to the
bliss point.
• Behav Regul theory works well for ratio scheds, but Matching
does better for interval scheds.
Selection by Consequences
• Recent interest in application of natural selection to
behavioral choice and reinforcement.
• Variation in behavior ensures that multiple Rs are available;
consequences select the ones that “survive.”
• Remains to be seen how valuable this approach is to
understanding reinforcement & onstrumental conditioning.