History of Psychology

circa 290 BC

Aristotle, a pupil (but not a follower) of Plato, is a supporter of the Hippocratic theory of mental disorders

circa 124

Asclepiades becomes the first to note the difference between acute and chronic mental disorders as well as distinguishing between illusions, delusions, and hallucinations.

circa 90

Aretaeus becomes the first to describe the phases of mania and melancholia and to consider these two pathological states as expressions of the same illness.

circa 180

Galen makes many original contributions concerning the anatomy of the nervous system and performs a major service to the future sciences of psychology, physiology, medicine, and biology by compiling and integrating existing knowledge in those fields.


The first mental hospital in the world is established in Baghdad. Treatment of the patients is thought to have been very humane.

circa 1484

Johann Sprenger and Heinrich Kraemer prepare the book, Malleus Maleicarum — directed by the papal bull of Pope Innocent VIII — to aid the clergy of Europe in the detection and exorcism of devils. The prevalent therapy for the mentally ill becomes threats, insults, curses, and various methods of physical torture.

circa 1510

Paracelsus publicly insists that ‘dancing mania’ is not demon possession but a disease that should be treated as any other disease.


The monastery of St. Mary of Bethlehem at London is officially converted into a mental asylum by King Henry VIII. Conditions there quickly become dangerous and chaotic, and treatment provided the patients is either nonexistent or cruel. The hospital eventually becomes popularly known as ‘Bedlam.’ See the motion picture Bedlam (1946): directed by Mark Robson, produced by Val Lewton; starring Boris Karloff and Anna Lee (with a small role by newcomer Jason Robards).


Reginald Scot publishes The Discovery of Witchcraft, which denied the common belief that demons cause mental disorders.


Rene Descartes publishes Passions of the Soul, affirming deductive reasoning, asserting the doctrines of duality and nativism, and making the ultimate pronouncement concerning the primacy of existence: cogito ergo sum (I think therefore I am).


Thomas Hobbs opposes Descartes’ notion of innate ideas and holds that sensations are the source of all knowledge. Hobbs initiated the philosophical school of (British) empiricism.


John Locke extends empiricism and becomes known as its founder. In his work Essay Concerning Human Understanding, he puts the essence of his doctrine in the famous comparison of an infant’s mind to a ‘blank slate’ or tabula rasa, and draws a distinction between primary and secondary qualities of matter.

circa 1730

George Berkeley asserts that there are no primary qualities; all knowledge is dependent upon the experiencing person. The only reality is mind.

circa 1740

David Hume argues that ‘mind’ is only a name for a flow of ideas, memories, imagination, and feelings. Mind is not a true entity but rather a secondary quality itself, like matter, that is only observable through the perception of a sentient organism.


David Hartley systematise and organises the various concepts of British Empiricism into the formal doctrine of associationism.


Benjamin Rush begins working for reform in the treatment of institutionalised patients in US (at Pennsylvania Hospital).


Philippe Pinel begins the reformation of mental institutions as director of La Bicetre of Paris. Later in his life, Pinel would be saved from the hands of a mob suspecting him of anti-revolutionary activities by a soldier he had once freed from asylum chains.


In Great Britain, William Tuke improves treatment of mental patients. Treatment methods are called Moral Therapy and include such methods as friendly association (support), discussion (group therapy), and purposeful activity.

German physician F J Gall (1758—1828) founds the practice of phrenology.


Thomas Young proposes the trichromatic theory of colour vision as a physiological limitation of human vision. As early as 1725, J C Le Blon expressed a primitive form of trichromacy but he, and most 18th-century writers, took it to be a property of the world rather than of human vision.


Lamarck publishes Recherches sur l’organisation des corps vivant.


W A Sarturner (1783—1841) isolates morphine.


British Empiricism rolls on… James Mill says ‘mind’ is developed from elements and can therefore be reduced to elements by analysis. Medical Institution of Yale College is founded.


Benjamin Rush publishes the first systematic treatise on psychiatry in the US, Medical Inquiries and Observations upon the Diseases of the Mind.


Johannes Muller publishes the first volume of Handbook of Physiology, summarising the physiological research of the period. In later years, Muller devised the doctrine of specific nerve energies.


Nurse Dorothea Dix begins her crusade to improve physical hygiene in asylums in the US. This eventually results in state funded and operated mental hospitals.

British Empiricism: John Stuart Mill says that elements may generate complex ideas but the ideas thus generated are not merely the sum of their component parts.


Soren Kierkegaard, champion of Existentialism, dies refusing the ministrations of the church.

circa 1857

Marshall Hall, pioneering the investigation of reflex behaviour, concludes that there are several levels of behaviour dependent upon certain broadly localised brain areas.

circa 1860

By this year, Dorothea Dix had convinced 38 states to build and maintain asylums to provide clean, safe living conditions for the mentally ill.

Ernst Weber begins bringing the experimental methods of physiology into the investigation of psychological processes. Weber develops the first truly quantitative law in psychology.

Weber’s Law: The amount of change needed to produce a just noticeable difference is a constant proportion of the original stimulus intensity.

Gustav Fechner would extend Weber’s work and advance psychological methods of measurement.

Gregor Mendal, Austrian monk, is investigating the basic properties of genetics in his pea garden.


Paul Broca discovers a major center in the brain for processing language located upon the 3rd lateral gyrus of the left frontal lobe.


Fritsch and E Hitzig find that electrical stimulation of certain frontal brain areas gives rise to motor responses.

Hermann von Helmholtz measures the rate of conduction of the nervous impulse and continues his development of theories of colour vision and hearing.


Friedrich Nietzsche publishes for the first time this year, further developing the philosophy of existentialism.


Wilhelm Wundt is analysing the content of consciousness via introspection and founds the world’s first psychological laboratory at the University of Leipzig, Germany.


Charles Darwin, the originator of the theory of evolution based upon the concept of survival of the fittest, dies.


Emil Kraepelin publishes Lehrguch der Psychiatrie, the first systematic classification of mental disorders.


Hermann Ebbinghaus publishes Uber das Gedachtnis (Concerning Memory), reporting his quantitative investigations of memory and learning.


William James publishes The Principles of Psychology, effectively demolishing the experimental introspective psychology of Wundt and helps prepare the way for different approaches to human behaviour such as functionalism and behaviourism. He becomes known as the founder of functionalism.


The American Psychological Association is founded.

James Rowland Angell receives the highest degree he ever earns, a Master’s of Arts from Harvard University. He will become a champion of Functionalism, instructor at the Universities of Minnesota and Chicago, Administrator of the University of Chicago, and President of Yale University.


Josef Breuer and Sigmund Freud publish Studies in Hysteria. Transference in the therapeutic relationship is first described.


Lightner Witmer, University of Pennsylvania, founds the first psychological clinic in the US.


Sigmund Freud publishes The Interpretation of Dreams


Ivan Petrovich Pavlov is investigating conditioned reflexes.

Alfred Adler meets Sigmund Freud this year and becomes a member of Freud’s inner circle.


Ivan Pavlov receives the Nobel Prize for Medicine for his work on the physiology of digestion.


The first practical test of intelligence is devised by Alfred Binet and Simon.


Ivan Pavlov publishes Conditioned Reflexes.


Sigmund Freud makes his only visit to the United States and delivers a series of lectures at Clark University.


Sigmund Freud’s lectures at Clark University are published as The Origin and Development of Psychoanalysis.

The International Psychoanalytic Association is founded with Carl Jung as its first president.

William James dies.


Alfred Adler parts with Sigmund Freud because of ‘theoretical issues’ and establishes his own school of psychoanalytic psychology. Adler’s psychoanalytic school of psychology is based upon the concept of feelings of inferiority.

Alfred Binet dies.


Carl Jung breaks from the Freudian circle, dissatisfied with Freud’s pansexual explanation of personality and Freud’s reluctance to approach the deeper layers of the unconscious (which Freud feared would result in psychoanalysis becoming associated with mysticism).

Jung publishes Symbols of Transformation.

Max Wertheimer develops Gestalt theory in Germany.


Edward Lee Thorndike provides the basis for the development of operant conditioning theory with his formulation of the Law of Effect. Working on his doctorial dissertation under the supervision of William James, Thorndike conducts several experiments to determine how cats would solve the problem of escaping from a box. The cats, to Thorndike’s surprise, do not systematically tackle the problem but instead seem to emit an extended series of random behaviours. However, after several trials, the cats became more prone to emit the response that results in their escape. Thorndike formulated the Law of Multiple Response to explain the tendency of an organism to emit species-typical responses in a hierarchy, and the Law of Effect to explain how a response low in the hierarchy could be moved up the hierarchy by its consequences.

John Broadus Watson publishes Psychology as the Behaviourist Views It.


Accidentally, ‘experimental neurosis’ is developed in Ivan Pavlov’s laboratory during discrimination experiments with dogs.

John B Watson publishes his text Behavior: An Introduction to Comparative Psychology.


The Stanford-Binet Intelligence Scale is published.


John B Watson publishes Psychology from the Standpoint of a Behaviorist.


John B Watson and his graduate assistant, Rosalee Rayner, demonstrate learned phobic responses in ‘Little Albert’ and conclude that classical conditioning can account for conditioned fear responses in human beings. Little Albert, while playing with a white rat (CS), is subjected to the loud and frightening noise of Watson banging on a suspended pipe (UCS). After several trials of this, Little Albert began crying at the sight of the white rat alone (CR). Later in the year, Watson is asked to resign his university post following the announcement of his plans to divorce his wife and marry Rayner.

Sigmund Freud publishes Beyond the Pleasure Principle.

Wolfgang Kohler publishes Physische Gestalten, interpreting Gestalt as a field theory.


Hermann Rorschach first publishes his inkblot test in Psychodiagnostik in Switzerland.


Hermann Rorschach dies.


Georg Groddeck publishes his book The Book of the It then posts the manuscript to Sigmund Freud. Freud incorporates the material into an article he had in progress about the Ego and the Ego-Ideal. Sigmund Freud publishes Das Ich und das Es (which was mistranslated into English as ‘The Ego and the Id’ but was literally The Ego and the It) which combined the concepts of Freud’s Ego and Ego-Ideal with Groddeck’s It into the totality of the human psyche. Groddeck was at least influenced in his thinking by the writings of philosopher Friedrich Nietzsche.


Jacques Loeb, prominent physiologist and champion of the mechanistic viewpoint in biology, dies.

Mary Cover Jones, former student of John B Watson, reports using early behavioural therapies in the case of ‘Peter.’

Kurt Koffka publishes The Growth of the Mind, further advancing Gestalt theory.


Wolfgang Kohler publishes The Mentality of Apes, further advancing Gestalt theory.


Martin Heideggar further develops the philosophy of existentialism in his publication Sein Und Zeit (Being and Time). The essence of existentialism, as put forth by Heideggar, is that the individual exists simply by virtue of his acting in the world, and the world exists only because there are individual minds to perceive it.

Operationism is developed and defended by Percy W Bridgman, physicist and mathematician, in his publication Logic of Modern Physics. Operationism holds that the validity of a scientific finding or theoretical construct is contingent upon the validity of the operations involved in arriving at that finding or construct.


Edward C Tolman publishes Purposive Behavior in Animals and Men, beginning the development of his gestalt-behaviouristic system.


Carl Jung publishes Psychological Types, attempting to bring order into the diversity presented by individual differences in personality through the delineation of a conceptual model which includes two basic attitudes (introversion and extroversion) and four essential psychological functions common to humankind (thinking and feeling, and sensation and intuition).


Ivan Pavlov dies.


The Stanford-Binet Intelligence Scale is revised.


Lauretta Bender introduces the Visual-Motor Gestalt Test.

Burrhus Frederic Skinner publishes The Behavior of Organisms, stating the principles of operant conditioning in operational terms.


Operationism comes under criticism. S S Stevens, American psychologist, points out in a key article that there are fundamental differences between physics and psychology, and that many psychologists believe that certain concepts can be useful even though not immediately specifiable in operational terms.

The Wechsler-Bellevue Intelligence Test, incorporating age norms and deviation IQs, is published.

Sigmund Freud dies.


B F Skinner is training pigeons to steer missiles into Japanese battleships.


Carl Rogers publishes Counseling and Psychotherapy, describing client-centred therapy for the first time.


Hathaway and McKinley publish the Minnesota Multi-phasic Personality Inventory.


Walter Cannon, who coined the term ‘homoeostasis’ to describe the physiological mechanism of state constancy in the body, dies.


Edwin R Gutherie and Horton publish Guthrie’s only known experiment. Gutherie supported a contiguity theory of learning.


B F Skinner publishes Walden Two.

Neal Miller demonstrates fear as an acquired drive.


E L Thorndike dies.


Kenneth Spence continues research upon Hull’s system, seeking the crucial experiment to determine if learning can occur without reinforcement.

William K Estes begins development of his stimulus-sampling theory of learning, which began as a form of stimulus-response associationism and an attempt to formalise Gutherie’s ideas.

John Dollard and Neal Miller publish Personality and Psychotherapy, applying learning principles to therapy.

P E Meehl publishes On the Circularity of the Law of Effect and reformulates the theory of reinforcement. According to Meehl, all reinforcers are transituational.


Hull revises his theory in Essentials of Behavior.


The first edition of the American Psychiatric Association’s Diagnostic and Statistical Manual is released.

Hull makes further revisions to his theory in his final publication, A Behavior System.

Charles Sherrington, who named the reflex arc, dies.


B F Skinner publishes Science and Human Behavior.


Fred D Sheffield develops the concept of reinforcement as events that elicit general locomotor excitation in his A Drive-induction Theory of Reinforcement.

Julian Rotter publishes Social Learning and Clinical Psychology, hoping to translate experimental theories into practical clinical procedures. His theory requires the inference of private actions (such as, expectancy) and value judgements (reinforcement value) by the subjects.


Kenneth Spence publishes Behavior Theory and Conditioning, revising Hull’s system yet again.


B F Skinner publishes Verbal Behavior.


Wolpe’s Psychotherapy by Reciprocal Inhibition helps start the behavioural therapy movement.

John B Watson dies.


David Premack begins his studies of high-probability behaviours having reinforcing effects.

Edwin Guthrie dies.

E C Tolman dies.


Hobart Mowrer publishes Learning Theory and Behavior, outlining his views historically from their origins in Hullian drive-reduction terms to their ‘final’ formulation in sign-expectancy, two factor theories. Mowrer is particularly critical of Neal Miller’s theory of fear reduction.


Carl Jung dies.


David Premack publishes Reversibility of the Reinforcement Relation and establishes high probability responses as adequate reinforcers of low-probability responses. The theory becomes known as the Premack Principle.

Thomas Kuhn publishes The Structure of Scientific Revolutions, arguing that important changes in science occur through revolutions and that paradigms, or scientific models, collapse and are replaced by new models.


Pierre Janet publishes The Major Symptoms of Hysteria, pioneering the psychodynamic approach to therapy.

Albert Bandura is investigating vicarious learning and will soon demonstrate that children who watch people behave aggressively, either in person or on video, tend to play more aggressively themselves.


E J Capaldi investigates the partial reinforcement effect.


M E P Seligman and Steven Maier develop the theory of Learned Helplessness.


Neal Miller and DiCara demonstrate the instrumental conditioning of changes in heart rate by rats. This erodes a long-standing distinction that instrumental conditioning works on voluntary responses and classical conditioning works on involuntary reflexes.


Abraham Maslow, humanistic psychologist who originated the Hierarchy of Needs concept, dies.


B F Skinner publishes Beyond Freedom and Dignity.

B F Skinner publishes About Behaviorism.


Neal Mackintosh publishes The Psychology of Animal Learning, still considered to be one of the leading authoritative texts in the area of learning theory.


William F Crowder trains the first bomb-detecting dogs in a practical application of learning theory, discrimination and generalisation.


Comparative psychologists Maury Haraway and Ernest Maples begin studying the species-typical vocalisations of gibbons.


The Diagnostic and Statistical Manual of Mental Disorders, 3rd Edition is released.

Jean Piaget dies.

John Dollard dies.


David Wechsler, originator of the Wechsler Scales for measuring intelligence, dies.


O H Mowrer dies.


Carl Rogers, founder of Humanistic Psychology, dies.


Konrad Lorenz dies.


William F Crowder dies.

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