4 Neobehaviorist Psychologists

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4 Neobehaviorist Psychologists

• Edward Tolman
• Edwin Guthrie
• Clark Hull
• B. F. Skinner

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Edward Tolman

• Cognitive behaviorism
• 1911 - Graduated from MIT with a degree in
  electrical chemistry
• 1915 Graduated from Harvard with a PhD in
  psychology
• Most influenced by Robert Yerkes who used
  Watsons textbook and who rejected the use of
  introspection

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Edward Tolman

• Taught at Northwestern 1915 1918 when he was
  fired for pacifist activities
• Moved to Cal Berkley where he taught for 40
  years

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Edward Tolmans Psychology

• Studied the behavior of rats running in mazes
• Determined that the rats behavior was more than
  building S -gt R connections
• Rats behaved with intelligence and purpose

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Purposive Behavior

• Watson excluded purpose and cognition from
  psychological study Tolman felt this was an
  error
• Attempted to develop a behaviorism based on
  objective behavior, but included the purpose of
  behaviors

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Purposive Behavior in Animals and Men

• Most of the book concerned rat behavior in mazes
• Completely rejected mentalistic psychologies and
  endorsed behaviorism
• Psychology should be the study of objective
  behavior and it should include behaviors that are
  purposive, goal-directed and cognitive

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Example of a purposive behavior

• When a rat learns to run a maze it not only
  expects to get a reward, but learns that a
  specific reward will be there
• Different rewards have different values to the
  animal
• When reward was switched to a less valued reward,
  rats ran slower and made more errors

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Latent learning and cognitive maps

• 1929 - Rats were placed on a maze with no reward
  and then later given a reward
• Control group food in the goal box on all 7
  days
• Ex. group 1 no food for 1st 6 days, food in
  goal box on day 7
• Ex. Group 2 no food for 2 days, food available
  on day 3 - 7
• Results experimental groups performed like the
  control the day after the transition from no food
  to food in the goal box

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Latent learning and cognitive maps

• Conclusion rats must have learned the maze
  during the unrewarded trial, and they developed a
  cognitive map of the maze.
• Tolman referred to this as latent learning
• Learning without reinforcement a major problem
  for more radical behaviorists

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Law of least effort

• Rats placed on an elevated maze with no walls and
  allowed to explore
• 3 routes to the goal box that were of different
  lengths
• Rats then made hungry and placed on the maze
  they chose the shortest route
• Block the shortest route, they took the second
  shortest, etc.
• Conclusion their cognitive map included the
  whole maze not just one route

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1937 Place Learning

• Presented in his APA presidential address
• Use of a plus maze to determine how rat solve
  mazes

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Response versus place learning

• Modified plus maze
• Response learning start at either S1 or S2
  food always found by turning left
• Place learning Start at either S1 or S2 food
  always at F1 or at F2
• Results response learning very slow place
  learning very rapid

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Tolmans model

• Three variables influence behavior
• Independent variable conditions of the
  experiment what is controlled
• Intervening variables subject variables, age,
  skill, past experiences
• Dependent variable what is measured
• Behavior as measured by the dependent variable is
  a function of the independent and intervening
  variables

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Two major criticisms of Tolman

• He did not develop a true theory of learning
  showing a clear theoretical position
• Objection to his writings as being subjective and
  mentalistic

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2 important contributions of Tolman

• Support of the rat as appropriate subjects for
  psychological study
• Most important was his realization that Watsons
  behaviorism had thrown out the baby with bath
  water in rejecting all mentalism

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Edwin Guthrie and Clark Hull

• 2 very different people
• Guthrie received a degree in mathematics, but
  became more interested in philosophy
• He read Bertram Russell and Whiteheads Principia
  Mathematic and decided the use of deduction in
  philosophy would never lead to an understanding
  of the mind

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Clark Hull

• A well-known psychologist who had studied
  aptitude testing and hypnosis for 12 years when
  he read Principia Mathematic
• He felt this work could serve as a model for a
  psychological system of behavior
• Both became behaviorists, but for 2 different
  reasons

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Edwin Guthrie

• 1912 - PhD in philosophy
• Changed from an interest in the association of
  ideas to the more behavioral perspective of the
  association of responses
• Very similar opinions to those of Watson
  minimized the importance of reinforcement
  maximized the importance of contiguity

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Contiguity Theory

• Behavior is a function of the environment
• If food is available, an animal will emit
  responses to obtain it successful responses
  will be learned
• The S-gtR association is learned through one trial
  learning

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The role of reinforcement

• Reinforcement (getting the food) is only
  important because it ends the activity
• The last act is the one that is learned and that
  learning persists
• Unsuccessful acts are not learned because they
  are displaced by later successful acts

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Studies supporting contiguity theory

• Prevailing theory animals would learn a task to
  maintain homeostasis
• Guthrie showed that rats would learn a task to
  get water sweetened with saccharin. No
  nutritional or survival value

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Studies supporting contiguity theory

• Male rats will learn to run a maze if a receptive
  female is in the goal box. Even if they are
  prevented from copulating
• Both presented as evidence of animals learning
  without being reinforced indicating that
  reinforcement was not important

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Movements versus whole acts

• Guthrie proposed
• Watson and others studied whole acts because
  they were easy to measure
• Movements that make up whole acts should be
  studied
• Individual movements are learned in one trial
  learning
• Putting these individual movements to create
  whole acts requires practice

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Criticisms of Guthrie's Contiguity theory

• Early appeal of his theory was its simplicity
• This simplicity was later criticized for ignoring
  or failing to address problems in learning his
  theory couldnt explain he had mistaken
  incompleteness for simplicity
• Theory based on very little experimental data.
  Took a more philosophical approach to theorizing

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Clark Hull

• His goal was to develop universal laws of
  behavior
• Major enduring contribution to psychology was the
  application of formal logic to psychological
  problems
• Form theoretical suppositions or constructs
• Develop predictions of the theory
• Test predictions

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Hulls behaviorism

• Greatest influences were Darwins theory of
  evolution - Importance of adaptability, natural
  selection, and continuity of behavior in
  evolution
• He did not study species specific behaviors
• Looking for universal laws that could explain
  both human and nonhuman behavior
• Mathematics attempted to develop very complex
  mathematic formulas that could predict behavior

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The importance of intervening variables

• Watson and others were interested in describing
  the formation of the connections between stimulus
  and response
• Hull more interested in the nature of the
  connections (habit strength) and the variables
  that influenced their development

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Hulls concept of reinforcement

• Watson reinforcement was only important in that
  it kept the animal on task
• Guthrie it ended the behavior and the last
  behavior was learned
• Hull reinforcement strengthened the connection
  between a stimulus and a response

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Hulls concept of reinforcement

• Positive reinforcement anything that reduces
  tension
• Negative reinforcement creates tension to be
  avoided
• Two issues to be addressed
• Motivation had to be part of reinforcement
• His approach had to hold for both humans and
  nonhumans

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The concept of drive

• Reinforcement meant the reduction of a drive
  state
• If drive increased, then the level of response
  would increase to decrease the level of drive
• Different species may have different drives, but
  reduction of drive was the basis of reinforcement

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Basis of Theory

• 1. Habit strengths could form in a single trial,
  but were strengthened through repetition and
  reinforcement
• Complex behaviors different stimuli may become
  associated with other stimuli and with more than
  one response
• The habit strength between the stimulus and
  different responses differed
• The response evoked by a stimulus depended on
  which response had the greatest habit strength

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2 additional variables added to formula

• Incentives some objects were more preferred 2
  objects may both reduce drive, but one increases
  the speed of learning because it is more
  preferred
• Inhibition
• Reactive inhibition
• Conditioned or learned inhibition

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Criticisms of Hulls drive reduction theory

• Behaviorists too much reliance on intervening
  variables incentives, drives, etc. not
  observable
• Humanists dehumanizing humans and ignoring
  individual differences
• His mathematic formulas called fantasies because
  they assume learning is a continuous process when
  it is not

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Hulls contributions

• Previously mentioned system of formal logic
  used in psychology
• His theories and ideas were so clear and well
  formulated that they became excellent targets for
  others

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B. F. Skinner the radical behaviorist

• 1930s and 1940s Guthrie and Hull were the
  leading behaviorists in psychology
• 1950s and 1960s behaviorism dominated by
  Skinner
• Tolmans works were neglected for this period,
  but later became important for the development of
  cognitive psychology

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Influences on Skinner

• Neurophysiologists Pavlov and Sherrington study
  of the reflex
• Watsons behaviorism

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Operant conditioning

• Classical conditioning the animal responds to
  the environment learning results from the
  environment
• Operant conditioning the animal operates on the
  environment the animal performs arbitrary
  behaviors and if a behavior is rewarded it will
  occur again
• The animal controls the response rate not the
  experimenter

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Schedules of reinforcement

• Accidental beginning he was studying the nature
  of reinforcement and only had enough food for a
  few trials
• 3 different schedules
• Continuous
• Ratio fixed and variable
• Interval fixed and variable

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Other contributions

• System of behavioral training called shaping
  use of successive approximations
• Behavior modification training

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Skinner and controversy

• Skinner sought out controversy
• Walden II utopian society based upon behavioral
  control
• When asked if his house was on fire and he could
  save his children or his books, he replied he
  would save his books. His writings would make
  greater contributions than his genes
• Heir conditioner
• Strongly attacked public education practices