Exogenous Theories: Skinner

Biographical Sketches

History of Social Learning Theory

Behaviorism

emphasis: individuals  should only be studied in terms of observable behavior

2 types:

methodological behaviorism – believes that inner experiences do not exist because they are unobservable (e.g., animals)

radical behaviorism – mental processes and structures may exist, but cannot be studied in verifiable ways; e.g., Skinner saw thoughts as byproducts

Classical Conditioning and Ivan Pavlov

A neutral stimulus (NS) is chosen and does not cause any particular reaction (e.g., a bell might cause looking behavior, but not salivation).

1. An unconditioned stimulus (US) is presented after NS
(e.g., pairing a bell with the presentation of food, for example)

2. US and CS pairing elicits an unconditioned response (UR). This transforms the NS into a conditioned stimulus (CS).
(e.g., bell + food ‡ salivation)

3. Over time, CS alone can elicit a conditioned response (CR)
    (e.g., bell causes salivation when presented alone)

But, no new behaviors are learned, only new signals for a reflexive response.

Roots of US Behaviorism


John Watson & conditioned fear – established behaviorism in the US

Edward Thorndike & the law of effect – new type of conditioning based on the response consequences

B.F. Skinner & operant conditioning – uncovered laws governing how behavior is shaped by its effects – behavior produce consequences which in turn affects behavior

operant = general class of behaviors (e.g., pecking at a key); each specific occurrence of the response = response
 
General Orientation to the Theory

STRUCTURAL COMPENENTS OF OPERANT CONDITIONING

Assumptions

Problems for Study
phenomena to be explained: basic laws that relate behavior to the environment; potential to explain on mathematical terms

4 factors involved:


Methods of Study


Internal Principles

A. contingent reinforcement – reinforcement follows the response; role of primary (unconditioned) and secondary (conditioned) reinforcers

B. discriminative stimulus – in operant conditioning, the operant follows the discriminative stimulus and precedes the reinforcing stimulus

C. Shaping - Successive approximations to desired behavior are reinforced

Bridge Principles

Schedules of reinforcement

1. Continuous reinforcement - Reinforcement comes after each desired response (often useful in shaping)

2. Intermittent or partial reinforcement

Ratio schedules:
i. Fixed-ratio: Reinforcement after fixed number of responses
ii. Variable-ratio: Reward after variable number of responses

Interval schedules
i. Fixed-interval: Reinforcement after constant time elapses
ii. Variable-interval: Reward after varying time intervals

3. concurrent schedules & extinction
if a behavior continues to occur even in the absence of reinforcement, it might mean that a concurrent schedule or random reinforcement was used

Generalization

stimulus generalization – transfer of previous learning to new situations
response generalization – different responses occur with the same discriminative stimulus (e.g., possible responses to a bike can include pedaling, balancing, steering, and later tricks)

Behavior chains

in order to get complex behaviors, simple behaviors must be chained together – reinforcement occurs for the last behavior in the chain

Change Mechanisms

reinforcement (generally) – 4 specific types:

Positive Reinforcement (R+) - Increases Behavior
Punishment - Decreases Behavior
Negative Punishment - Decreases Behavior
Negative Reinforcement (R-) - Increases Behavior

THE RESEARCH & EVALUATION

Discrimination learning: changing behavior in the face of a discriminative stimulus

Contributions & Criticisms

+ scientific methodology
+ laws of operant conditioning
+ practical applications
+ behavior modification & token economies

– reductionism
– verbal learning
– definition of behavior
– nature of reinforcement

 Evaluation

Scientific worthiness
testability                             (high)
external validity                   (high)
predictive validity                (med)
internal consistency             (high)
theoretical economy            (high)

Developmental adequacy
temporality                                      (present)
cumulativity                                     (present)
directionality                                    (absent)
new mode of organization                (absent)
increased capacity for self control    (absent)

Pedagogical Usefulness
interpretability        (med)
versatility                (high)
availability              (high)
guidance                 (high)