1. Rene Descartes
French philosopher and mathematician who proposed mind-body interaction and the doctrine of innate ideas.
1637

2. John Locke
British philosopher who rejected Descartes’ notion of innate ideas and insisted the mind at birth is a “blank slate” (tabula rasa).
1690

3. Philippe Pinel
Released the first mental patients from their chains at the Bicetre Asylum in France and advocated more humane treatment of mental patients.
1793

4. Ernst Weber
Published The Sense of Touch in which he discussed the just noticeable difference (jnd) and what we now call Weber’s Law.
1834

5. Phineas Gage
Suffered massive brain damage when a large iron rod accidently pierces his brain, leaving his intellect and memory intact but altering his personality.
1848

6. Charles Darwin
Published On the Origin of Species by Means of Natural Selection, synthesizing much previous work on the theory of evolution, including that of Herbert Spencer, who coined the phrase “survival of the fittest.”
1859

7. Wilhelm Wundt
First laboratory devoted specifically to the study of psychological phenomenon in Leipzig, Germany.
1879

8. Sigmund Freud
Published Interpretation of Dreams to begin a study of the unconscious mind.
1900

9. Mary Whiton Calkins
Became the first woman president of the American Psychological Association.
1905

10. Ivan Pavlov
Began publishing studies of conditioning in animals.
1905

11. Margaret Floy Washburn
Became the first female psychology Ph. D. awarded at Cornell University in 1894.
Her principal research interests were animal behavior and the basic psychological processes of sensation and perception. The book she is best known for was “The Animal Mind.”
1908

12. John B. Watson
Outlined the tenets of behaviorism in a Psychological Review article, “Psychology as the Behaviorist Views It.”
1913

13. Leta Stetter Hollingsworth
Published The Psychology of Subnormal Children, an early classic in the study of varying levels of intelligence.
1920

14. Francis Cecil Sumner
Received a Ph. D. degree in psychology from Clark University, becoming the first African-American to earn a psychology doctorate.
1920

15. Hermann Rorschach
Swiss psychologist who introduced the Rorschach Inkblot test.
1921

16. Mary Cover Jones
Reported reconditioning a fear reaction in a child (Peter), a forerunner of systematic desensitization developed by Joseph Wolpe.
1924

17. Walter Cannon
Coined the term “homeostasis,” discussed the fight- or-flight response and identified hormonal changes associated with stress.
1932

18. Solomon Asch
Published studies of effects of conformity on judgment of line length.
1950

19. Carl Rogers Published Client-Centered Therapy
Humanistic psychologist who emphasized the importance of current environmental influences on our growth potential.
1951

20. Abraham Maslow
Proposed a hierarchy of motives ranging from physiological needs to self actualization.
1954

21. George Miller
In his Psychological Review article, “The Magical Number Seven, Plus or Minus Two: Some Limits on Our Capacity for Processing Information,” Miller coined the term chunk for memory researchers.
1956

22. Burrhus Frederick Skinner
A leading behaviorist, he rejected introspection and studied how consequences shape behavior.
With Charles Ferster publishes Schedules of Reinforcement.
1957

23. Noam Chomsky
Reasoned that we are born with an innate language acquisition device.
His critical review of B. F. Skinner’s Verbal Behavior appeared in the journal Language.
1959

24. Harry Harlow
Outlined “The Nature of Love,” his work on attachment in monkeys.
1959

25. Albert Ellis
Reason and Emotion in Psychotherapy appeared; a milestone in the development of rational-emotive therapy (RET).
1962

26. Raymond Cattell
Distinguished between fluid and crystallized intelligence.
1963

27. Stanley Milgram
“Behavioral Study of Obedience” appeared in the Journal of Abnormal and Social Psychology.
1963

28. Beatrix and Allen Gardner
Began training a chimpanzee (Washoe) in American Sign Language at the University of Nevada, Reno.
1966

29. Albert Bandura Published Social Learning Theory. Bobo Doll studies.
1971

30. Elizabeth Loftus
Published Eyewitness Testimony.
1979

31. Roger Sperry
Received a Nobel prize for research on split-brain patients.
1981

32. Martin Seligman
Published Learned Optimism, which foreshadows the “positive psychology” movement.
1991