Toward a Science of Behavior Background –2 nd decade of 20 th century: disagreement within psychology On value of introspection On existence of mental.

Toward a Science of Behavior

• Background– 2nd decade of 20th century: disagreement

within psychology• On value of introspection• On existence of mental elements• On the need to remain a pure (unapplied)

science

– Functionalism movement was evolutionary, not revolutionary

Attack of the Behaviorists– Protest against both structuralism and

functionalism

– Deliberately abrupt

– Designed to shatter the two dominant schools

John B. Watson (1878-1958)• Watsonian Behaviorism

– Ultra-Scientific

– Dealt solely with observable behavioral acts

– Objective descriptions of the data

– Rejection of mentalistic concepts and terms

– Consciousness comparable to soul, introspection irrelevant

John B. Watson (1878-1958)• Watson organized and

promoted already existing ideas– Philosophical tradition of

objectivism and mechanism

– Animal psychology

– Behaviorism was a Functional psychology

Behaviorism• Basic ideas were not new,

philosophically speaking– Descartes (mechanistic description of

the body)– Comte (positivism; Emphasis on

undebatable facts)– Positivism became part of the

zeitgeist in science• Resulting science of behavior viewed

human beings as machines

Animal Psychology• Behaviorism’s Background

– Watson: “Behaviorism is a direct outgrowth of studies in animal behavior....”

– Animal psychology was a product of evolutionary theory

• Science was willing to accept the mental life of nonhumans..

Plant Psychology

…perhaps a little too willing.• Alfred Binet (1889)

– The Psychic Life of Micro-Organisms (1889)

• Francis Darwin (1908)– Consciousness in plants

Jacques Loeb (1859-1924)• Significant step toward objectivity in animal

psychology• Tropism or “involuntary forced movement”

as basis for theory of animal behavior: consciousness not necessary

• Did not totally reject consciousness for more evolved species

• It’s all about reflexes - Consciousness revealed by associative memory which is just a very complex association

• Taught Watson at Chicago

Tools of the Behaviorist’s Trade• Rats, Ants, and the Animal Mind

– Robert Yerkes (Yale): Inspired by Pavlov and strengthened comparative psychology in the U.S.• The Dancing Mouse (1905)

– Willard S. Small• 1900: introduced the rat maze• Used mentalistic terms

– Charles Henry Turner• A Preliminary Note on Ant Behavior (1906)• May have inspired Watson’s adoption of the term

“Behaviorism”

• Lack of funding for comparative psychologists– Harvard president: “no future in

Yerkes's...Comparative psychology”– His students took up applied jobs when none

available in comparative– Margaret Floy Washburn publishes The Animal

Mind (1908) which may have been the last book of the time to attribute mental states to animals

The Death of Comparative Psychology

– 1906: Pavlov lecture reprinted in Science– 1909: description of Pavlov’s work published by

Yerkes and Morgulis in Psychological Bulletin– 1911: Journal of Animal Behavior (later Journal

of Comparative Psychology) published– Objective psychology and Watson’s research

supported by Pavlov’s work– Conscious experience disappearing from animal

psychology

…and the resurrectionYou can study animals, but be objective.

Hans (Again) 1904• Wilhelm von Osten: Animal intelligence

• Oskar Pfungst (Stumpf’s student)

• Owned by Wilhelm von Osten– Osten’s goal: prove humans and animals have

similar mental processes– Animals simply lack education

• After exposure, von Osten accused Hans of deceit

• Watson used this case to demonstrate the dangers of making assumptions about the conscious operations of the animal mind

• Hans’ “intelligence” would have been understood immediately if it was explored according to Behaviorist models

Hans (Again)

American Connectionism• Edward Lee Thorndike (1874-1949)

– Educated in the U.S.– Wanted to study child development at

Harvard with James – settled for chicks– Finished Ph.D. with Cattell at Columbia– Animal Intelligence (1898): First

psychology dissertation based on nonhumans

– Eventually got back to humans and education

Edward Lee Thorndike (1874–1949)• Connectionism

The mind is a device that connects…situations, elements of situations, and compounds of situations with…responses, readiness to respond, facilitations, inhibitions, and directions of responses.

• Learning is connecting!

• A revised version of Locke’s Associationism

Edward Lee Thorndike (1874–1949)• Edward Lee Thorndike (1874-1949)

– Laboratory work and learning theory of connectionism were critical antecedents for behaviorism.

– Thorndike's work with cats and puzzle boxes drove his formulation of the law of exercise and the law of effect.

– He later published the truncated law of effect that cast doubt on the effectiveness of punishment.

Edward Lee Thorndike (1874–1949)• Cats and Puzzle Boxes

– Trap a cat…random behavior will evolve in to a specific behavior aimed at generating results

– Consequences led to the “stamping in” or “stamping out” of responses (Trial-and-Accidental-Success-Learning)

Edward Lee Thorndike (1874–1949)

• Law of Effect: If a behavior generates a desired result, it will be reinforced and vise versa

• Law of Exercise: Repetition will reinforce behavior ONLY of results are generated– Practice is not enough

– Punishment may be ineffective!

– (This doesn’t mean learning isn’t happening!)

Edward Lee Thorndike (1874–1949)

• Moved from animals to education

• His work supported the identical elements transfer theory over the doctrine of formal discipline.– DFD: “Latin will improve your

ability to study all subjects.”– IETT: “Mental exercises are fine, but

if you want to understand algebra, study math!”

Edward Lee Thorndike (1874–1949)

• After Thorndike

– Decreased role of consciousness

– Increased focus on experimental method

– Mechanism: behavior reduced to S-R elements

Talk is Cheap• “…I must acknowledge that the honor of having

made the first steps along this path belongs to E.L. Thorndike. By two or three years his experiments preceded ours…”

– Pavlov, 1928

Ivan Petrovitch Pavlov (1849-1936)• In general

– His work helped shift of associationism from subjective ideas to objective physiological responses

– Provided Watson with a new method

• Pavlov’s life– Intended to study for the priesthood– Read about Darwin, chose to study animal

physiology– Member of Russian (and soviet)

intelligentsia– Total dedication to research– 1890: professor of pharmacology at St.

Petersburg, Russia– 1904 nobel prize for work on digestion

Ivan Petrovitch Pavlov (1849-1936)

Russian PhysiologistsIvan Pavlov (1849-1936)• Shifted from physiology to psychology

with research into psychical reflex (classical conditioning).

• Variations of classical conditioning:

- US, UR, CS, CR• Evaluated the processes of extinction,

spontaneous recovery, disinhibition, stimulus generalization, discrimination etc.

Experimental Control • The tower of silence

– Pavlov concerned about outside influences affecting his results

– Controlled for such influences by designing special cubicles for dog and for experimenter

– Dog could not see experimenter

• Painstaking research– Standardized experimental conditions– Rigorous controls– Elimination of sources of error

Pavlov• Later work focused on experimental neurosis.• Assaulted the nervous system of dogs and studied

their responses.• Ultramaximal inhibition, a state of protective shock

with three different aftereffects:– Equivalent phase – same saliva, regardless of stimulus– Paradoxical phase – less triggers more and vise versa– Ultraparadoxical phase – attracted to negative stimuli

and repulsed by positive stimuli (human conversion experiences?).

Pavlov• Nobel prize in 1904

– The conditioned response is the basic unit of Behaviorism

– Work still stands due to meticulous experimental techniqueTower of Silence

• Declared intellectual war on Köhler and Gestalt psychology

Where’s my Prize?

• E.B. Twitmyer– U. Penn– 1902: dissertation on

reflexes– 1904: presentation at APA

• Topic: knee-jerk reflex• Findings: Conditioned

Knee-Jerk reflex

Twitmyer’s Experiment

Animal Rights• Reflexology, Behaviorism and

Animals– SPCA: England 1824

– ASPCA: U.S. 1866

• Pavlov, Darwin, and James all advocated “humane” use of animals

Summary of Pavlov

– Demonstrated study of higher mental processes in physiological terms

– Broad practical applicability– Continued the tradition of mechanism and atomism– Provided psychology with a basic element of

behavior– Behavior could be reduced to elements and studied

in experimental laboratory