Learning Principles: B. F. Skinner

• Burrhus Frederic Skinner (March 20, 1904 – August 18, 1990)

Early life• B.F. Skinner was born on March 20, 1904

in Susquehanna, a small railroad town in the hills of Pennsylvania just below Binghamton, New York.

• Skinner’s father was a lawyer• With one younger brother, he grew up in

a home environment he described as "warm and stable".

Early life (Cont…)• Skinner went to Hamilton College, New York,

as he wanted to become a writer.• After getting his B.A. in English literature in

1926, Skinner attended Harvard University, where he later received a PhD in 1931.

• His literary skills disenchanted him, and was inspired by John B. Watson’s Behaviorism. He acquired a degree in psychology, which led to the development of his influential operant behaviorism.

Books by B.F. Skinner• The Behavior of Organisms: An Experimental

Analysis (1938)• Walden Two (1948)• Science and Human Behavior (1953)• Schedules of Reinforcement (1957)• Verbal Behavior (1957)• The Analysis of Behavior: A Program for Self

Instruction (with James Holland, 1961)• The Technology of Teaching (1968)• Contingencies of Reinforcement: A Theoretical

Analysis (1969)

Books by B.F. Skinner (Cont…)• Beyond Freedom and Dignity (1971)• About Behaviorism (1974)• Particulars of My Life: Part One of an Autobiography (1976)• Reflections on Behaviorism and Society (1978)• The Shaping of a Behaviorist: Part Two of an Autobiography

(1979)• Notebooks (with Robert Epstein, 1980)• Enjoy Old Age: A Program of Self-Management (with M.

Vaughan, 1983)• A Matter of Consequences: Part Three of an Autobiography

(1983)• Upon Further Reflection (1987)• Recent Issues in the Analysis of Behavior (1989)

Operant Conditioning(Instrumental Conditioning)

• Skinner is regarded as the father of Operant Conditioning

• Skinner believed that the best way to understand behavior is to look at the causes of an action and its consequences. He called this approach operant conditioning

• It was the dominant school in American psychology from the 1930s through the 1950s.

B. F. Skinner’s influence

Skinner's theory of operant conditioning was based on thework of Thorndike (1905).• Law of Effect: rewarded behavior is likely to recur.

• OperantAny activity behavior that operates upon the environment to generate consequences

• Operant ConditioningThe behavior is followed by consequence, and the nature of the consequence modifies the organisms tendency to repeat the behavior in the future

B. F. Skinner’s Experiment

Operant Conditioning

There are two types of consequences:positive (sometimes called pleasant)

Strengthens Behavior

negative (sometimes called unpleasant)

Weakens behavior

Reinforcer Any event that STRENGTHENS the behavior it follows.There are 2 types of reinforcement1. Positive reinforcement2. Negative reinforcement

Positive Reinforcement

Strengthens a response by presenting a pleasant stimulus after a response.

Negative Reinforcement

• Strengthens a response by reducing or removing an aversive (unpleasant) stimulus.

Punishment

An event that DECREASES the behavior that it followsThere are 2 types of punishment1. Positive Punishment2. Negative Punishment

Positive Punishment

It involves the presentation of an unfavorable event or outcome in order to weaken the response it follows

Negative PunishmentWhen a favorable event or outcome is removed after a behavior occurs, to decrease the following response

Do rewards or punishment work?

Reinforcement Schedules

• Stimuli are presented in the environment according to a schedule of which there are two basic categories:

ContinuousIntermittent

Continuous Reinforcement• Continuous reinforcement refers to

reinforcement being administered to each instance of a response

Intermittent reinforcement

Intermittent reinforcement lies between continuous reinforcement and extinction. It is the random or periodic administration of reinforcement for the desired response.

TYPE MEANING OUTCOME

Fixed Ratio

Reinforcement depends on a definite number of responses

Activity slows after reinforcement and then picks up

Variable Ratio

Number of responses needed for reinforcement varies

Greatest activity of all schedules

Fixed Interval

Reinforcement depends on a fixed time

Activity increases as deadline nears

Variable Interval

Time between reinforcement varies

Steady activity results

Give me a child and I’ll shape him

into anything

If you're old, don’t try to

change yourself,

change the environment

The real problem is not whether

machines think, but whether

men do