Psychology at the Dawn of the 20th Century

• Overview– 1892-1923: Structuralism dominated American

psychology and was first supplemented and then replaced by Functionalism

– 1924: Titchener conceded that Watsonian Behaviorism had engulfed the United States

– 1930: Other varieties of behaviorism emerged

The Stages1. 1913-1930: Watsonian Behaviorism2. 1930-1960: Neobehaviorism

• Core of psychology is the study of learning• Most behavior can be accounted for by the

laws of conditioning• Psychology must adopt the principle of

operationism (operational definitions)

3. 1960-present: Sociobehaviorism and the return to cognitive processes

Non-Watsonian Behaviorism• Karl S. Lashley (1890-1958)

– Watson’s student• Trained rats and then sliced their brains.

– Law of Mass Action– Principle of Equipotentiality

• Cortex is complicated and learning cannot be explained by simple Point-to-Point connections

• Actually confirmed Watson’s claim for the value of objective methods in psychology

Operationism ( or Operational Positivism)

• Percy W. Bridgman (1882-1961)– Physicist who promoted operationism

within physics (Nobel Prize 1946)– Psychologists followed (at least

through the 1920s-30s)• Make the language of science objective:

– Instead of “hunger” state that the animals were deprived for 24 hrs.

– Consciousness has no place in scientific psychology; It can’t be measured!

Neobehaviorism• Edward C. Tolman (1886-1959)

– Left MIT to study with Koffka• Gestalt background

– Landed at U.C. Berkeley– 1912: studies with Koffka– Dissatisfied with Watsonian

Behaviorism– Developed Purposive Behaviorism

• Professional experience– Instructor at Northwestern University– 1918 hired by the U. C. at Berkeley

• Taught comparative psychology

• Conducted research on learning in rats

• Formed his own form of behaviorism after becoming dissatisfied with Watson's

– During WWII was the office of strategic services (OSS), which later became the central intelligence agency (CIA)

Edward C. Tolman

Purposive Behaviorism

• How can one measure Purpose?– Behavior “reeks” of purpose– Learning is evidence of purpose– Intervening variables are the actual

determinants of behavior• S-R substituted with S-O-R• S-Hunger-R

Purposive Behaviorism• Rejected Thorndike’s Law of Effect

– Reinforcement has little to do with learning

– Repetition helps an animal understand the link between environment and expectations. These links are Sign Gestalts

– A rat in a maze makes choices based on expectations. When an expectation is confirmed, a Sign Gestalt is strengthened.

Purposive Behaviorism• Maze Experiments

– Rats completed mazes with the help of cognitive maps, not by following a sequence of movements

– Vary starting point – Rat still gets cheese!– Expectations could be modified

• The attribution of purpose to behavior was criticized by Watsonian behaviorists because it implied the existence of conscious processes

• Tolman responded that whether or not presence or degree of organisms were conscious was not relevant to him or did it affect behavioral responses

• Central focus was overt responses

Purposive Behaviorism

Intervening variables• The initiating causes as well as the results

of behavior must be observable and operationally defined

• Causes are independent variables– Environmental stimuli– Psychological drives– Heredity– Previous training– Age

Purposive Behaviorism

Learning theory

• Learning was central in Tolman’s purposive behaviorism.

• Rejected Thomdike's law of effect– Reward has little influence on learning– Proposed a cognitive explanation of learning in

its place

Purposive Behaviorism

Behaviorism in Sum

• A forerunner of the cognitive movement

• Intervening variables– Engendered scientific respect for operationally

defining internal states– A necessary and useful format for dealing with

hypothetical constructs used by Guthrie, Hull, and Skinner

The Age of the Rat

• The rat as an important research subject

• 1930’s-1960’s primary subject for neobehaviorists

• Assumption that one could generalize from rats to other animals and humans

• Simple, easy to study, readily available

Clark Leonard Hull (1884-1952)

• Hull’s life– Ill health

– Poor eyesight

– Polio at age 24

– Meet challenges with persistence and resolve

– Intense motivation to achieve

– University of Wisconsin (Ph.D. 1918): studied engineering before psychology

– Early work revealed continued interest in using objective methods • Concept formation• Effects of tobacco on behavioral efficiency• Applied area: Aptitude Testing (1928)• Practical methods of statistical analysis• Invented a machine for calculating

correlations• Hypnosis and Suggestibility (1933)

Clark Leonard Hull (1884-1952)

• 1929: research professor at Yale• Interested in developing a theory of behavior

based on Pavlovian conditioning– 1930’s articles about basic conditioning and its

usefulness in understanding complex higher-order behaviors

• Principles of Behavior (1943), a theoretical attempt to account for all behavior

• A Behavior System (1952), the final form of Hull’s theory

Clark Leonard Hull (1884-1952)

The Spirit of Mechanism• Omitted mentalistic terms, including

consciousness and purpose

• Used mechanistic terms

• Human behavior – Mechanistic, robotic– Automatic– Reducible to the language of physics

• Machines could be constructed that would display human cognitive functions

Drive Theory• Drive

– An intervening variable

S > D > R– a “stimulus arising from a state

of tissue need that…activates behavior”

– Drive reduction is the only basis of reinforcement

Drive Theory• Drive strength is empirically

determined using key characteristics of the environment or of the resulting behavior

• Length of deprivation– Intensity, strength, and energy

expenditure of the behavior– Hull emphasized the latter measure

of response strength

• Reinforcement: reduction or satisfaction of a drive

• Primary drives: arise from a state of physical need and are vital to the organism’s survival

• Secondary drives– Are learned– Are situations or environmental stimuli

associated with the reduction of primary drives– As a result of the association with primary

drives, become drives themselves

Drive Theory

•SER = SHR x D x V x K–

SER : Potential for action• Will you smoke the cigarette?

–SHR : Habit strength• How long have you been smoking?

– D : Drive strength• How long since last smoke?

– V : Stimulus intensity dynamism• Is anyone else smoking?

– K : Incentive motivation• Are there rewards or consequences?

• “When a stimulus-response relationship is followed by a reduction in a bodily need, the probability increases that on subsequent occasions the same stimulus will evoke the same response”– Reinforcement defined in terms of the reduction of

a primary need– Primary Reinforcement (reduction of a primary

drive) is the basis for learning– Secondary Reinforcement (reduction of a secondary

drive)

Law of Primary Reinforcement

• Habit Strength: the strength of the S-R connection– A function of the number of reinforcements that have

occurred– Refers to the persistence of the conditioning

• Learning cannot occur without reinforcement– Reinforcement necessary for drive reduction– Hull’s system as ultimately based on need-reduction is

contrasted with Tolman’s cognitive approach

Law of Primary Reinforcement

Comment on Hull• Experienced the same type of attacks as those

directed at Watson and other behaviorists

• Pronounced effect on psychology through– The amount of research generated and provoked– The achievements of his students and followers– Defending, extending, and expounding objective

behaviorism

• Called a “theoretical genius”

Burrhus F. Skinner (1904-1990)

• One of the most influential psychologists in the 20th century– Beginning in 1950’s, the

major embodiment of behaviorism

– Large and loyal group of followers

B.F. Skinner (1904-1990)

• Developed and wrote about subjects that had considerable impact– Behavioral control– Behavior modification– Utopian society (Walden Two)– Beyond Freedom and Dignity, a

national bestseller

• Became a celebrity in his own right

B.F. Skinner (1904-1990)

• Skinner’s life– Built things as a child and worked with and

observed animals– Used his early life experiences as a base for his

system of psychology– A product of past reinforcements– Seemingly predetermined, lawful, and orderly

• 1925: Hamilton college (NY): degree in English, no courses in psychology, phi beta kappa

• Worked at writing for two years after favorable feedback from Robert Frost

• Depressed by lack of success as a writer Read about Pavlov's and Watson's experimental work

• 1931: PhD from Harvard

B.F. Skinner (1904-1990)

• Dissertation: a reflex is a correlation between S and R• 1938: The Behavior of Organisms; Covered basic

points of his system• 1953: Science and Human Behavior; Basic textbook

for his system• Toward end of life

– Lived in a controlled environment

– Enjoyed writing: a source of positive reinforcement

– Published “Intellectual Self-Management in Old Age”

– Described his feelings of dying with leukemia in a radio interview

B.F. Skinner (1904-1990)

• 1990: vigorously attacked the growth of cognitive psychology in a paper delivered at the Boston meeting of the American Psychological Association

• 1990 (final article): “can psychology be a science of mind?”

• Died in 1990 at the age of 86

B.F. Skinner (1904-1990)

Skinner’s Behaviorism• Devoted to the study of responses

• Concerned with describing behavior rather than explaining it

• Dealt only with observable behavior

• No presumptions about internal entities– The “Empty Organism” approach– Internal physiological and mental events exist

but not useful to science

Skinner’s Behaviorism• Single-subject design

– Large numbers of subjects not necessary – Statistical comparisons of group means not

necessary– A single subject provides valid and replicable

results• Cannot predict behavior of a particular individual

from knowledge of the average individual

– Journal of the experimental analysis of behavior established because mainstream journals did not accept an N of 1.

Operant conditioning• Contrasted with respondent (Pavlovian) conditioning,

which is elicited by a specific observable stimulus• Operant behavior

– Occurs without an observable external stimulus– Operates on the organism’s environment– The behavior is instrumental in securing a stimulus

such as food – More representative of everyday learning– Most effective approach to science of behavior: the

study of the conditioning and extinction of operants

• Studied bar pressing in the plexiglas “skinner box”: the rate of response

• Law of acquisition: “the strength of an operant behavior increases when it is followed by the presentation of a reinforcing stimulus”– Key variable: reinforcement– Practice provides opportunities for additional

reinforcement• Thorndike and Hull: explanatory• Skinner: strictly descriptive

Operant conditioning

Skinner Boxes

Could be programmed and automated!!!

Research Foci

1. Role of punishment in response acquisition

2. Schedules of reinforcement

3. Extinction of operants

4. Secondary reinforcement

5. Generalization

Subjects included humans as well as animals

• Reinforcement is necessary in operant behavior and can be delivered on different Schedules.

• Continuous Schedule: Pellet for every push– Fast acquisition and fast loss of behavior

• Partial Schedule– Fixed or variable time of delivery or rate

• Slower acquisition and slower loss

– Ratio (of responses)• Fast learning as long as ratio isn’t too high

Reinforcement Schedules

Is Conversation Operationally Conditioned?

• Sounds made in speech are a type of behavior– Can be reinforced by other sounds or behavior– Listener controls speaker’s subsequent behavior

through reinforcement or punishment

Inventions and Public Profile

• Aircribs– Mechanized environment

invented to relieve menial labor

– Not commercially successful

– Daughter reared in it with no ill effects

Teaching Machine• Teaching machine

– Invented in the 1920’s by Pressey– Not enthusiastically received

• Surplus of teachers• No public pressure to improve

learning• Promoted by Skinner in the 1950s

– Better reception, but computers were ready for applications

– Technology of Teaching (1968)

Pigeon Missile

• Pigeon-guided missiles– Developed by skinner during WWII– They Worked!– Military wasn’t impressed.

• Novel of a 1,000-member rural community

• Behavioral control through positive reinforcement

• Outgrowth of skinner’s midlife depression, expressing his own conflicts and despair

• Reflected mechanism of Galileo, Newton, and the associantionists

Walden Two (1948)

Applied Psychology

• Behavior modification through positive reinforcement is alive and well

• Operant conditioning is widely used in psychiatric hospitals and Business

• Research emphasizes the effectiveness of reinforcement over punishment (most of the time)

Criticisms of Skinner’s Behaviorism• His extreme positivism• His opposition to theory and willingness to

extrapolate beyond the data– Grand predictions about society based on a

single rat?• His position that all behaviors are learned

– Instinctive drift could ruin an animal show• His position on verbal behavior

– Chomsky argues for an inherited ability to construct sentences

Criticisms of Skinner’s Behaviorism

• ". . . There is no reason," he declares, "why progress toward a world in which people may be automatically good should be impeded." No reason at all - provided you are willing to view yourself as a baby, a retardate or a psychotic.– Ayn Rand reviewing Beyond Freedom and Dignity

Skinner’s Contributions

• Contributions of Skinner’s Behaviorism– Operant conditioning works!– Reinforcement schedules follow Skinner’s laws

– Shaped American psychology for 30 years

– His goal: the improvement of society

– Strength and ramifications of his radical behaviorism

Sociobehaviorism

– Social learning or sociobehaviorist approach

• Stimulated by many, including some behaviorists

• Reflected the broader cognitive revolution in psychology

– 1995: consciousness overtly and publicly returned to psychology

Albert Bandura (1925-)

• Background– Experience with the psychopathology of

ordinary life– 1952: PhD from the university of Iowa– 1981: APA distinguished scientific

contribution award

Albert Bandura (1925-)

• Social cognitive theory– Behavioristic

• Less extreme than skinner’s behaviorism

• Reflects current zeitgeist in its interest in cognitive variables

– Research focus: observation of the behavior of humans in interaction

– Emphasizes the role of reinforcement in learning and behavior modification

Albert Bandura (1925-)

– Cognitive aspect stresses the influence of thought processes on external reinforcement schedules

– Reactions to stimuli are self-activated, person-initiated rather than automatic

– Reinforcer effective if• Person is consciously aware of what

is being reinforced• Person anticipates the same

reinforcer if the behavior is repeated

– Vicarious reinforcement: learning “by observing how other people behavior and seeing the consequences of their behavior” rather than directly experiencing the consequences of one’s own

– Assumes human capacity to anticipate and appreciate those outcomes

– One can regulate one’s behavior by • Imagining those consequences, and• Making a conscious selection of the behavior to

manifest

– Is like the S-O-R model, with O being equal to cognitive processes

• Cognitive processes distinguish Bandura’s views from skinner’s – Who/what controls behavior?

• Skinner: whoever controls reinforcers• Bandura: whoever controls the models in a

society

Behavior modification

– Bandura’s goal: change or modify socially undesirable behavior

– Focus: external aspects of abnormality, i.E., Behavior

– The use of modeling– Bandura’s form of behavior therapy is

widely used in diverse settings and has strong research support

Comment– Criticized by traditional behaviorists who

deny cognitive processes – Positive aspects of Bandura’s theory

• Widely accepted in psychology• Consistent with the functionalism of

American psychology • Objective• Amenable to precise laboratory methods• Responsive to the current cognitive zeitgeist• Applicable to practical problems

Julian Rotter (1916-)• Background

– Grew up comfortably in Brooklyn– Father lost his business in 1929 crash

• Turning point for the 13-year-old• Triggered life-long concern for social justice• Lesson on the effects of situational

conditions on personality and behavior

– Read Freud and Adler in high school– Learned that jobs scarce in psychology

• Cognitive processes– 1947: the first to use the term social

learning theory– Cognitive approach to behaviorism– Invokes the existence of subjective

experiences– Criticized Skinner’s study of single

subjects in isolation– Relies on rigorous, well-controlled

laboratory research– Studies only human subjects in

social interaction

– Deals with cognitive processes more extensively than Bandura• Both external stimuli and the reinforcement they

provide affect behavior

– Four cognitive principles determine behaviors1. Expectation of amount and kind of reinforcement2. Estimation of probability the behavior will lead to

a particular reinforcement3. Differential values of reinforcers and assessment

of their relative worth 4. Different people place different values on the

same reinforcer

• Locus of control: “beliefs about the source of our reinforcers” – Beliefs about the source of one’s

reinforcements – Internal locus of control: belief that

reinforcement depends on one’s own behavior

– External locus of control: belief that “reinforcement depends on outside forces such as fate, luck, or the actions of other people

– Is learned in childhood from the ways one is treated

• Comment– Rotter’s theory attracts followers who

• Are experimentally oriented• Think cognitive variables influence behavior

– A great many studies support his theory, particularly regarding internal and external locus of control

The fate of behaviorism

• Cognitive challenge to behaviorism from within modified the behaviorist movement

• Sociobehaviorists still consider themselves behaviorists – Are called methodological behaviorists because they employ

internal cognitive processes– Are contrasted with radical behaviorists like Watson and

skinner who do not deal with presumed internal states• Skinnerian behaviorism peaked in the 1980s• Declined after skinner’s death in 1990

• Today’s behaviorism, particularly in applied psychology, is different from forms it took from 1913 (Watson) to 1990 (skinner)

• In an evolutionary sense, the spirit of behaviorism still lives

Bandura et al., 1961