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This article is a generaltimeline of psychology.

• c. 1550 BCE – TheEbers Papyrus mentioneddepression andthought disorders.^[1]
• c. 600 BCE – Many cities in Greece had temples toAsklepios that provided cures for psychosomatic illnesses.^[2]
• 540–475Heraclitus^[3]
• c. 500Alcmaeon^[3] – suggested theory of humors as regulating human behavior (similar toEmpedocles' elements)
• 500–428Anaxagoras^[3]
• 490–430Empedocles^[3] proposed a first natural, non-religious system of factors that create things around, including human characters. In his model he used four elements (water, fire, earth, air) and four seasons to derive diversity of natural systems.
• 490–421Protagoras^[3]
• 470–399Socrates^[3] – Socrates has been called the father of western philosophy, if only via his influence on Plato and Aristotle. Socrates made a major contribution topedagogy via his dialectical method and toepistemology via his definition of true knowledge as true belief buttressed by some rational justification.
• 470–370Democritus^[3] – Democritus distinguished between insufficient knowledge gained through the senses and legitimate knowledge gained through the intellect—an early stance onepistemology.
• 460 BC – 370 BCE –Hippocrates introduced principles of scientific medicine based uponnaturalistic observation and logic, and denied the influence of spirits and demons in diseases. Introduced the concept of "temperamentum"("mixture", i.e. 4temperament types based on a ratio between chemical bodily systems.^[4][5]Hippocrates was among the first physicians to argue that brain, and not the heart is the organ of psychic processes.
• 387 BCE –Plato suggested that the brain is the seat of mental processes. Plato's view of the "soul" (self) is that the body exists to serve the soul: "God created the soul before the body and gave it precedence both in time and value, and made it the dominating and controlling partner." fromTimaeus^[6]
• c. 350 BCE –Aristotle wrote on thepsuchê (soul) inDe Anima, first mentioning thetabula rasa concept of the mind.
• c. 340 BCE –Praxagoras
• 371–288Theophrastus^[3]
• 341–270Epicurus^[3]
• c. 320Herophilus^[3]
• c. 300–30Zeno of Citium taught the philosophy ofStoicism, involvinglogic andethics. In logic, he distinguished between imperfect knowledge offered by the senses and superior knowledge offered by reason. In ethics, he taught that virtue lay in reason and vice in rejection of reason. Stoicism inspiredAaron Beck to introducecognitive behavioral therapy in the 1970s.^[7]
• 304–250Erasistratus^[3]
• 123–43 BCE –Themison of Laodicea was a pupil ofAsclepiades of Bithynia and founded a school of medical thought known as "methodism." He was criticized by Soranus for his cruel handling of mental patients. Among his prescriptions were darkness, restraint by chains, and deprivation of food and drink.Juvenal satirized him and suggested that he killed more patients than he cured.^[4]
• c. 100 BCE – TheDead Sea Scrolls noted the division of human nature into two temperaments.^[8]

• c. 50 –Aulus Cornelius Celsus died, leavingDe Medicina, a medical encyclopedia; Book 3 covers mental diseases. The term insania, insanity, was first used by him. The methods of treatment included bleeding, frightening the patient, emetics, enemas, total darkness, and decoctions of poppy or henbane, and pleasant ones such asmusic therapy, travel, sport, reading aloud, and massage. He was aware of the importance of the doctor-patient relationship.^[9]
• c. 100 –Rufus of Ephesus believed that the nervous system was instrumental in voluntary movement and sensation. He discovered the optic chiasma by anatomical studies of the brain. He stressed taking a history of both physical and mental disorders. He gave a detailed account of melancholia, and was quoted by Galen.^[4]
• 93–138 –Soranus of Ephesus advised kind treatment in healthy and comfortable conditions, including light, warm rooms.^[4]
• c. 130–200 –Galen "was schooled in all the psychological systems of the day: Platonic, Aristotelian, Stoic, and Epicurean"^[5] He advanced medicine by offering anatomic investigations and was a skilledphysician. Galen developed further the theory of temperaments suggested byHippocrates, that people's characters were determined by the balance among four bodily substances. He also distinguished sensory from motor nerves and showed that the brain controls the muscles.
• c. 150–200 –Aretaeus of Cappadocia^[5]
• 155–220Tertullian^[3]
• 205–270Plotinus wroteEnneads a systematic account of Neoplatonist philosophy, also nature of visual perception and how memory might work.^[6]
• c. 323–403 –Oribasius compiled medical writings based on the works ofAristotle,Asclepiades, andSoranus of Ephesus, and wrote on melancholia in Galenic terms.^[4]
• 345–399 –Evagrius Ponticus described a rigorous way of introspection within the early Christian monastic tradition. Through introspection, monks could acquire self-knowledge and control their stream of thought which signified potentially demonic influences. Ponticus developed this view inPraktikos, his guide to ascetic life.^[10]
• c. 390 –Nemesius wroteDe Natura Hominis (On Human Nature); large sections were incorporated in SaintJohn Damascene'sDe Fide Orthodoxia in the eighth century. Nemesius' bookDe Placitis Hippocratis et Platonis (On the Doctrines of Hippocrates and Plato) contains many passages concerning Galen's anatomy and physiology, believing that different cavities of the brain were responsible for different functions.^[4][6]
• 397–398 –St. Augustine of Hippo publishedConfessions, which anticipated Freud by near-discovery of the subconscious.^[11] Augustine's most complete account of the soul is inDe Quantitate Animae (The Greatness of the Soul). The work assumes a Platonic model of the soul.^[6]
• 5th century –Caelius Aurelianus opposed harsh methods of handling the insane, and advocated humane treatment.^[4]
• c. 423–529 –Theodosius the Cenobiarch founded a monastery at Kathismus, near Bethlehem. Three hospitals were built by the side of the monastery: one for the sick, one for the aged, and one for the insane.^[4]
• c. 451 – PatriarchNestorius of Constantinople: his followers dedicated themselves to the sick and became physicians of great repute. They brought the works ofHippocrates,Aristotle, andGalen, and influenced the approach to physical and mental disorders in Persia and Arabia^[4]

• 625–690 –Paul of Aegina suggested that hysteria should be treated by ligature of the limbs, and mania by tying the patient to a mattress placed inside a wicker basket and suspended from the ceiling. He also recommended baths, wine, special diets, and sedatives for the mentally ill. He described the following mental disorders: phrenitis, delirium, lethargus, melancholia, mania, incubus, lycanthropy, and epilepsy
• c. 800 – The firstbimaristan was built inBaghdad. By the 13th century, bimaristans grew into hospitals with specialized wards, including wards for mentally ill patients.^[12]
• c. 850 –Ali ibn Sahl Rabban al-Tabari wrote a work emphasizing the need forpsychotherapy.^[13]
• c. 900 –Ahmed ibn Sahl al-Balkhi urged doctors to ensure that they evaluated the state of both their patients' bodies andsouls, and highlighted the link between spiritual or mental health and overall health.^[14]
• c. 900 –al-Razi (Rhazes) promoted psychotherapy and an understanding attitude towards those with psychological distress.^[15]

• 1025 – InThe Canon of Medicine,Avicenna described a number of conditions, includinghallucination,insomnia,mania,nightmare,melancholia,dementia,epilepsy,paralysis,stroke,vertigo andtremor.^[16]
• c. 1030 –Al-Biruni employed anexperimental method in examining the concept ofreaction time.^[17]
• c. 1180 – 1245Alexander of Hales
• c. 1190 – 1249William of Auvergne
• c. 1200 –Maimonides wrote aboutneuropsychiatric disorders, and describedrabies andbelladonna intoxication.
• 1215–1277Peter Juliani taught in the medical faculty of the University of Siena, and wrote on medical, philosophical and psychological topics. He was personal physician toPope Gregory X and later became archbishop and cardinal. He was elected pope under the nameJohn XXI in 1276.^[6][18]
• c. 1214 – 1294Roger Bacon advocated for empirical methods and wrote on optics, visual perception, and linguistics.
• 1221–1274Bonaventure
• 1193–1280Albertus Magnus
• 1225 –Thomas Aquinas
• 1240 –Bartholomeus Anglicus publishedDe Proprietatibus Rerum, which included a dissertation on the brain, recognizing that mental disorders can have a physical or psychological cause.
• 1247 –Bethlehem Royal Hospital in Bishopsgate outside the wall of London, one of the most famous old psychiatric hospitals was founded as a priory of the Order of St. Mary of Bethlem to collect alms for Crusaders; after the English government secularized it, it started admitting mental patients by 1377 (c. 1403), becoming known as Bedlam Hospital; in 1547 it was acquired by the City of London, operating until 1948; it is now part of the BritishNHS Foundation Trust.^[19]
• 1266–1308Duns Scotus
• c. 1270 –Witelo wrotePerspectiva, a work on optics containing speculations on psychology, nearly discovering the subconscious.
• 1295Lanfranc writesScience of Cirurgie^[6]
• 1317–1340 –William of Ockham, an English Franciscan friar and scholastic philosopher and theologian, is commonly known forOccam's razor, the methodological principle that the simplest explanation is to be preferred. He also produced significant works on logic, physics, and theology, advancing his thoughts about intuitive and abstracted knowledge.
• c. 1375 – English authorities regarded mental illness as demonic possession, treating it withexorcism andtorture.^[20]
• c. 1400 –Renaissance Humanism caused a reawakening of ancient knowledge of science and medicine.
• 1433–1499Marsilio Ficino was a renowned figure of the Italian Renaissance, a Neoplatonist humanist, a translator of Greek philosophical writing, and the most influential exponent of Platonism in Italy in the fifteenth century.^[5]
• c. 1450 – The pendulum in Europe swings, bringingwitch mania, causing thousands of women to be executed for witchcraft until the late 17th century.

• 1590 – Scholastic philosopherRudolph Goclenius coined the term "psychology"; though usually regarded as the origin of the term, there is evidence that it was used at least six decades earlier byMarko Marulić.

• c. 1600–1625 –Francis Bacon was an English philosopher, statesman, scientist, lawyer, jurist, author, and pioneer of the scientific method. His writings on psychological topics included the nature of knowledge and memory.
• 1650 –René Descartes died, leavingTreatise of the World, containing his dualistic theory of reality, mind vs. matter.
• 1672 –Thomas Willis published the anatomical treatiseDe Anima Brutorum, describing psychology in terms of brain function.
• 1677 –Baruch Spinoza died, leavingEthics, Demonstrated in Geometrical Order, Pt. 2 focusing on the human mind and body, disputing Descartes and arguing that they are one, and Pt. 3 attempting to show that moral concepts such as good and evil, virtue, and perfection have a basis in human psychology.
• 1689 –John Locke publishedAn Essay Concerning Human Understanding, which claims that the human mind is a Tabula Rasa at birth.

• 1701 –Gottfried Wilhelm Leibniz published theLaw of Continuity, which he applied to psychology, becoming the first to postulate an unconscious mind; he also introduced the concept of threshold.^[21]
• 1710 –George Berkeley publishedTreatise Concerning the Principles of Human Knowledge, which claims that the outside world is composed solely of ideas.
• 1732 –Christian Wolff publishedPsychologia Empirica, followed in 1734 byPsychologia Rationalis, popularizing the term "psychology".
• 1739 –David Hume publishedA Treatise of Human Nature, claiming that all contents of mind are solely built from sense experiences.
• 1781 –Immanuel Kant publishedCritique of Pure Reason, rejecting Hume's extreme empiricism and proposing that there is more to knowledge than bare sense experience, distinguishing between "a posteriori" and "a priori" knowledge, the former being derived from perception, hence occurring after perception, and the latter being a property of thought, independent of experience and existing before experience.
• 1783 –Ferdinand Ueberwasser designated himselfProfessor of Empirical Psychology and Logic at the Old University of Münster; four years later, he published the comprehensive textbookInstructions for the regular study of empirical psychology for candidates of philosophy at the University of Münster which complemented his lectures on scientific psychology.^[22]
• 1798 –Immanuel Kant proposed the first dimensional model of consistent individual differences by mapping the fourHippocrates'temperament types into dimensions of emotionality and energetic arousal.^[23] These two dimensions later became an essential part of all temperament and personality models.

• c. 1800 –Franz Joseph Gall developed cranioscopy, the measurement of the skull to determine psychological characteristics, which was later renamedphrenology; it is now discredited.
• 1807 –Georg Wilhelm Friedrich Hegel publishedPhenomenology of Spirit (Mind), which describes his thesis-antithesis-synthesis dialectical method, according to which knowledge pushes forwards to greater certainty, and ultimately towards knowledge of the noumenal world.
• 1808 –Johann Christian Reil coined the term "psychiatry".

• 1812 –Benjamin Rush became one of the earliest advocates of humane treatment for the mentally ill with the publication ofMedical Inquiries and Observations Upon Diseases of the Mind,^[24] the first American textbook on psychiatry.^[25]

• 1829 –John Stuart Mill's fatherJames Mill publishedAnalysis of the Phenomena of the Human Mind (2 vols.).^[26]

• 1840 –Frederick Augustus Rauch (1806–1841) publishedPsychology, or a View of the Human Soul, including Anthropology
• 1843 –Forbes Benignus Winslow (1810–1874) publishedThe Plea of Insanity in Criminal Cases, helping establish the plea of insanity in criminal cases in Britain.
• 1844 –Søren KierkegaardThe Concept of Anxiety, the first exposition onanxiety.
• 1848 – Vermont railroad workerPhineas Gage had a 3-foot rod driven through his brain and jaw in an explosives accident, permanently changing his personality, revolutionizing scientific opinion about brain functions being localizable.
• 1849 –Søren Kierkegaard publishedThe Sickness Unto Death.

• 1852 –Hermann Lotze publishedMedical Psychology or Physiology of the Soul.
• 1856 –Hermann Lotze began publishing his 3-volume magnum opusMikrokosmos (1856–64), arguing that natural laws of inanimate objects apply to human minds and bodies but have the function of enabling us to aim for the values set by the deity, thus making room for aesthetics.
• 1859 –Pierre Briquet publishedTraite Clinique et Therapeutique de L'Hysterie.

• 1860s –Franciscus Donders first used human reaction time to infer differences in cognitive processing.
• 1860 –Gustav Theodor Fechner publishedElements of Psychophysics, founding the subject ofpsychophysics.
• 1861 –Paul Broca discovered an area in the leftcerebral hemisphere that is important for speech production, now known asBroca's area, foundingneuropsychology.
• 1869 –Francis Galton publishedHereditary Genius, arguing foreugenics. He went on to foundpsychometrics,differential psychology, and thelexical hypothesis of personality.

• 1872 –Douglas Spalding published his discovery ofpsychological imprinting.
• 1874 –Wilhelm Wundt publishedGrundzüge der physiologischen Psychologie (Principles of Physiological Psychology), the first textbook of experimental psychology.
• 1878 –G. Stanley Hall was awarded the first PhD on a psychological topic from Harvard (in philosophy).
• 1879 – Wilhelm Wundt opened the first experimental psychology laboratory at theUniversity of Leipzig in Germany.

• 1882 – TheSociety for Psychical Research was founded in England.
• 1883 –G. Stanley Hall opened the first American experimental psychology research laboratory atJohns Hopkins University.
• 1883 –Emil Kraepelin publishedCompendium der Psychiatrie.
• 1884 –Ivan Pavlov began studying the digestive secretion of animals.
• 1884 –Tourette's Syndrome was first described.
• 1885 –Hermann Ebbinghaus publishedÜber das Gedächtnis (On Memory), a groundbreaking work based on self-experiments, first describing the learning curve, forgetting curve, and spacing effect.
• 1886 –John Dewey published the first American textbook on psychology, titledPsychology.
• 1886 –Vladimir Bekhterev established the first laboratory of experimental psychology in Russia atKazan University.
• 1886 –Sigmund Freud began private practice inVienna.
• 1887 –Georg Elias Müller opened the 2nd German experimental psychology research laboratory inGöttingen.
• 1887 –George Trumbull Ladd (Yale) publishedElements of Physiological Psychology, the first American textbook to include a substantial amount of information on the new experimental form of the discipline.
• 1887 –James McKeen Cattell founded an experimental psychology laboratory at theUniversity of Pennsylvania, the 3rd in the United States.
• 1887 –G. Stanley Hall founded theAmerican Journal of Psychology with a $500 contribution supplied byRobert Pearsall Smith of theAmerican Society for Psychical Research.
• 1888 –William Lowe Bryan founded the United States' 4th experimental psychology laboratory atIndiana University.
• 1888 –Joseph Jastrow founded the United States' 5th experimental psychology laboratory at theUniversity of Wisconsin–Madison.
• 1888 –G. Stanley Hall leftJohns Hopkins for the presidency of the newly foundedClark University in Worcester, Massachusetts
• 1889 –James Mark Baldwin published the first volume of hisHandbook of Psychology, titled "Sense and Intellect".
• 1889 –Edmund Sanford, a former student ofG. Stanley Hall founded the United States' 6th experimental psychology laboratory at Clark University.
• 1889 –Edward Cowles founded the United States' 7th experimental psychology laboratory at theMcLean Asylum in Waverley, Massachusetts
• 1889 –Harry Kirke Wolfe founded the United States' 8th experimental psychology laboratory at theUniversity of Nebraska.

• 1890 –Christian von Ehrenfels publishedOn the Qualities of Form, foundingGestalt psychology.
• 1890 –William James publishedThe Principles of Psychology.
• 1890 –James Hayden Tufts founded the United States' 9th experimental psychology laboratory at theUniversity of Michigan.
• 1890 –G. T. W. Patrick founded the United States' 10th experimental psychology laboratory at theUniversity of Iowa.
• 1890 –James McKeen Cattell left Pennsylvania forColumbia University where he founded the United States' 11th experimental psychology laboratory.
• 1890 –James Mark Baldwin founded the first permanent experimental psychology laboratory in the British Empire at theUniversity of Toronto.
• 1891 –Frank Angell founded the United States' 12th experimental psychology laboratory at theCornell University.
• 1891 –Edvard Westermarck described theWestermarck effect, where people raised early in life in close domestic proximity later become desensitized to close sexual attraction, raising theories about the incest taboo.
• 1892 –G. Stanley Hall et al. founded theAmerican Psychological Association (APA).
• 1892 –Edward Bradford Titchener took a professorship atCornell University, replacingFrank Angell who left forStanford University.
• 1892 –Edward Wheeler Scripture founded the experimental psychology laboratory atYale University, the 19th in United States.
• 1892–1893 –Charles A. Strong opened the experimental psychology laboratory at theUniversity of Chicago, the 20th in the United States, at whichJames Rowland Angell conducted the first experiments offunctionalism in 1896.
• 1894 –Margaret Floy Washburn was the first woman to be granted a PhD in Psychology after she studied underE. B. Titchener atCornell University.
• 1894 –James McKeen Cattell andJames Mark Baldwin founded thePsychological Review to compete withHall'sAmerican Journal of Psychology.
• 1895 –Gustave Le Bon publishedThe Crowd: A Study of the Popular Mind.
• 1896 –John Dewey published the paperThe Reflex Arc Concept in Psychology,^[27] foundingfunctionalism.
• 1896 – The first psychological clinic was opened at theUniversity of Pennsylvania byLightner Witmer; although often celebrated as marking the birth ofclinical psychology, it was focused primarily on educational matters.
• 1896 –Edward B. Titchener, student ofWilhelm Wundt and originator of the terms "structuralism" and "functionalism" publishedAn Outline of Psychology.
• 1897 –Havelock Ellis publishedSexual Inversion.
• 1898 –Boris Sidis publishedThe Psychology of Suggestion: A Research into the Subconscious Nature of Man and Society.
• 1899 – On 4 NovemberSigmund Freud publishedThe Interpretation of Dreams (Die Traumdeutung), marking the beginning ofpsychoanalysis, which attempts to deal with theOedipal complex.

• 1900 –Sigmund Freud publishedThe Psychopathology of Everyday Life.
• 1903 –John B. Watson graduated from the University of Chicago; his dissertation on rat behavior has been described as a "classic of developmental psychobiology" by historian of psychologyDonald Dewsbury.
• 1903 –Helen Thompson Woolley published her doctoral dissertation,The Mental Traits of Sex, for which she had conducted the first experimental test of sex differences.^[28]
• 1904 –Ivan Pavlov won the Nobel Prize for his studies of conditioning. This was the first Prize given for research adopted by psychologists.
• 1904 –Charles Spearman published the articleGeneral Intelligence in theAmerican Journal of Psychology, introducing theg factor theory ofintelligence.
• 1905-Mary Calkins was the first woman elected president of theAmerican Psychological Association.
• 1905 –Alfred Binet andTheodore Simon created theBinet-Simon scale to identify students needing extra help, marking the beginning of standardizedpsychological testing.
• 1905 –Edward Thorndike published thelaw of effect.
• 1905 –Sigmund Freud publishedThree Essays on the Theory of Sexuality.
• 1906 – TheJournal of Abnormal Psychology was founded byMorton Prince, for whichBoris Sidis was an associate editor and significant contributor.
• 1908 –Sigmund Freud published the paperOn the Sexual Theories of Children, introducing the concept ofpenis envy; he also published the paper 'Civilized' Sexual Morality and Modern Nervous Illness.
• 1908 –Wilfred Trotter published the first paper explaining theherd instinct.
• 1909 –Sigmund Freud lectured atClark University, winning over the U.S. establishment.

• 1910 –Sigmund Freud founded theInternational Psychoanalytical Association (IPA), withCarl Jung as the first president, andOtto Rank as the first secretary.
• 1910 –Grace Helen Kent and J. Rosanoff published theKent-Rosanoff Free Association Test^[29]
• 1910 –Boris Sidis opened the private Sidis Psychotherapeutic Institute at Maplewood Farms in Portsmouth, New Hampshire for the treatment of nervous patients using the latest scientific methods.
• 1911 –Alfred Adlerleft Freud's Psychoanalytic Group to form his own school of thought, accusing Freud of overemphasizing sexuality and basing his theory on his own childhood.
• 1911 – TheAmerican Psychoanalytic Association (APsaA) was founded.
• 1911 –William McDougall, founder ofHormic Psychology publishedBody and Mind: A History and Defence of Animism, claiming that there is an animating principle in Nature and that the mind guides evolution.
• 1912 –Max Wertheimer publishedExperimental Studies of the Perception of Movement, helping foundGestalt Psychology
• 1913 –Carl Jung developed his own theories, which became known asAnalytical Psychology.
• 1913 –Jacob L. Moreno pioneeredgroup psychotherapy methods in Vienna, which emphasized spontaneity and interaction; they later became known aspsychodrama andsociometry.
• 1913 –John B. Watson publishedPsychology as the Behaviorist Views It, sometimes known as "The Behaviorist Manifesto".
• 1913 –Hugo Münsterberg publishedPsychology and Industrial Efficiency, considered today as the first book onIndustrial and Organizational Psychology.
• 1914 –Boris Sidis publishedThe Foundations of Normal and Abnormal Psychology, where he provided the scientific foundation for the field of psychology, and detailed his theory of the moment consciousness.^[30]
• 1917 –Sigmund Freud publishedIntroduction to Psychoanalysis.

• 1920 –John B. Watson and his assistantRosalie Rayner conducted theLittle Albert experiment, usingclassical conditioning to make a young boy afraid of white rats.
• 1921 –Sigmund Freud publishedGroup Psychology and the Analysis of the Ego.
• 1921 –Jacob L. Moreno conducted the first large scale publicpsychodrama session at theKomedienhaus in Vienna;^{[citation needed]} he moved to New York in 1925.
• 1921 –Melanie Klein began to develop her technique of analyzing children.^[31]
• 1922 –Karen Horney began publishing a series of 14 papers (last in 1937) questioning Freud's theories on women, foundingfeminist psychology.
• 1922 –Boris Sidis publishedNervous Ills: Their Cause and a Cure, a popularization of his work concerning the subconscious and the treatment of psychopathic disease.
• 1923 –Sigmund Freud publishedThe Ego and the Id.
• 1924 –Jacob Robert Kantor foundedinterbehavioral psychology based on John Dewey's psychology and Albert Einstein's relativity theory.
• 1924 –Otto Rank publishedThe Trauma of Birth, coining the term "pre-Oedipal". Freud had originally praised him for such, but changed his stance and as such caused their falling out.
• 1926 –Otto Rank gave the lecture "The Genesis of the Object Relation", foundingobject relations theory.
• 1927 –Ivan Pavlov publishedConditioned Reflexes, containing his theory ofclassical conditioning.
• 1928 –Jean Piaget publishedJudgment and Reasoning in the Child.
• 1928 –Shoma Morita published Morita Therapy: The True Nature of Shinkeishitsu (Anxiety-based Disorders), which contains his peripheral theory of consciousness, while noting Freud's theory of the unconscious. (Translation by A. Kondo, Edited by P. LeVine in 1998, SUNY Press)
• 1929 –Edwin Boring publishedA History of Experimental Psychology, pioneering the history of psychology.
• 1929 –Lev Vygotsky foundedcultural-historical psychology.

• 1930 –Edwin Boring discussed the Boring figure.
• 1931 –Gordon Allport et al. published theAllport-Vernon-Lindzey Study of Values, which defines six major value types.
• 1932 –Journal of Personality founded as first personality psychology research periodical originally titled Character and Personality.
• 1933 –Pyotr Gannushkin publishedManifestations of Psychopathies.^[32]
• 1933 –Clark L. Hull publishedHypnosis and Suggestibility, proving that hypnosis is not sleep and founding the modern study of hypnosis.
• 1933 –Wilhelm Reich publishedCharacter Analysis andThe Mass Psychology of Fascism.
• 1934 –Lev Vygotsky publishedThought and Language (Thinking and Speech).
• 1934 –Ruth Winifred Howard became the first African American woman to earn a PhD in psychology.^[33]
• 1935 –John Ridley Stroop developed a color-word task to demonstrate the interference of attention, theStroop effect^[34]
• 1935 –Helen Flanders Dunbar publishedEmotions and Bodily Changes: A Survey of Literature on Psychosomatic Interrelationships;^[35] in 1942 she founded theAmerican Psychosomatic Society (American Society for Research in Psychosomatic Problems),^[36] and was the first editor of the society's journalPsychosomatic Medicine: Experimental and Clinical Studies, founded in 1939.^[37]
• 1935 –Henry Murray andChristiana Morgan of Harvard University published theThematic Apperception Test (TAT).
• 1935 –Theodore Newcomb began the Bennington College Study,^[38] which ended in 1939, documenting liberalization of women students' political beliefs, along with the effects of proximity on acquaintance and attraction.
• 1936 –Kurt Lewin publishedPrinciples of Topological Psychology,^[39] containing Lewin's Equation B = f (P, E), meaning that behavior is a function of a person in their environment.
• 1936 –Wilhelm Reich publishedThe Sexual Revolution.
• 1936 –Kenneth Spence published an analysis of discrimination learning in terms of gradients of excitation and inhibition, showing that mathematical deductions from a quantitative theory could generate interesting and empirically testable predictions.
• 1936 – ThePsychometric Society was founded byLouis Leon Thurstone, who proposed dividing general intelligence into seven primary mental abilities (PMAs).
• 1938 –B.F. Skinner published his first major workThe Behavior of Organisms: An Experimental Analysis, introducingbehavior analysis.
• 1939 –Alan Hodgkin andAndrew Huxley published a classic report in the journalNature of the first recording of anaction potential.
• 1939 –Neal E. Miller et al. published thefrustration-aggression theory, which claims that aggression is the result of frustration of efforts to attain a goal.
• 1939 –David Wechsler developed theWechsler-Bellevue Intelligence Scale.
• 1939 – On 1 September World War II began with the German invasion of Poland; on 20 SeptemberAdolf Hitler signed theEuthanasia Decree,^[40] written by psychologistMax de Crinis, resulting in theAktion T4 euthanasia program; on 23 SeptemberSigmund Freud committed physician-assisted suicide in London on the Jewish Day of Atonement; on 31 October his archrivalOtto Rank died of a kidney infection in New York City after uttering the word "comical";Wilhelm Reich fled to New York, coining the wordorgone and building "orgone accumulators", which got him in trouble with the psychiatric establishment and the federal government.

• 1940 –Edwin Boring discussed themoon illusion.
• 1941 –Erich Fromm publishedEscape from Freedom, foundingpolitical psychology.
• 1941 –B.F. Skinner andWilliam Kaye Estes introduced theconditioned emotional response (CER)/conditioned fear response (CFR) paradigm via electric shocks given to rats.
• 1942 –Ludwig Binswanger foundedexistential therapy.
• 1942 –Carl Rogers publishedCounseling and Psychotherapy, suggesting that respect and a nonjudgmental approach to therapy is the foundation for effective treatment of mental health issues.
• 1943 –J. P. Guilford developed theStanine (Standard Nine) test for the U.S. Air Force to evaluate pilots.
• 1943 –Clark L. Hull publishedPrinciples of Behavior, establishing animal-based learning and conditioning as the dominant learning theory.
• 1943 –Leo Kanner publishedAutistic Disturbances of Affective Contact, the first systematic description of autistic children.
• 1943 –Abraham Maslow published the paperA Theory of Human Motivation, describingMaslow's hierarchy of needs.
• 1944 –Zach Andrew andCameron Peter publishedMyer's Psychology Second Edition where they revolutionized the approach of learned Psychology
• 1945 – TheJournal of Clinical Psychology was founded.
• 1946 –Kurt Lewin foundedaction research.
• 1946 –Stanley Smith Stevens published hislevels of measurement theory.
• 1947 –Jerome Bruner publishedValue and Need as Organizing Factors in Perception, founding New Look Psychology, which challenges psychologists to study not just an organism's response to a stimulus but also its internal interpretation.
• 1947 –Kurt Lewin coined the term "group dynamics".
• 1947Nikolai Bernstein summarized his research on the measurement of actions using his original devices that became a beginning of a new discipline of kinesiology^[41]
• 1948 –Alfred Kinsey of Indiana University publishedSexual Behavior in the Human Male.
• 1949 – TheBoulder Conference outlined thescientist-practitioner model of clinical psychology.
• 1949 –Donald Hebb publishedThe Organization of Behavior: A Neuropsychological Theory, in which he provided a detailed, testable theory of how the brain could support cognitive processes, revolutionizingneuropsychology and makingMcGill University a center of research.
• 1949 –David Wechsler published theWechsler Intelligence Scale for Children (WISC).

• 1950 –Karen Horney summarized her ideas in her magnum opusNeurosis and Human Growth: The Struggle Toward Self-Realization.^[42]
• 1950 –Erik Erikson publishedChildhood and Society, in which he introduced histheory on the stages of psycho-social development and the concept of anidentity crisis.
• 1950 –Rollo May publishedThe Meaning of Anxiety.
• 1951 –Solomon Asch published theAsch conformity experiments, demonstrating the power ofconformity in groups.
• 1951 –Morton Deutsch publishedInterracial Housing: A Psychological Evaluation of a Social Experiment, producing scientific evidence of the bad effects of segregated housing, helping to end it in the U.S.
• 1951 –Carl Rogers published his magnum opusClient-Centered Therapy.
• 1951 –Lee Cronbach published his measure of reliability, now known asCronbach's alpha.
• 1952 – TheDiagnostic and Statistical Manual of Mental Disorders (DSM) was published by the American Psychiatric Association (APA), marking the beginning of modern mental illness classification; it was revised in 1968, 1980–7, 1994, 2000 and 2013.
• 1952 –Hans Eysenck started a debate onpsychotherapy with his critical review,^[43] claiming that psychotherapy had no documented effect, andpsychoanalysis had negative effects.^[44]
• 1953 –Alfred Kinsey publishedSexual Behavior in the Human Female.
• 1953 –Nathaniel Kleitman of the U. of Chicago discoveredrapid eye movement sleep (REM), founding modernsleep research.
• 1953 –David McClelland proposedneed theory.
• 1953 –B.F. Skinner outlinedbehavioral therapy, lending support for behavioral psychology via research in the literature.
• 1953 – TheCode of Ethics for Psychologists was developed by the American Psychological Association (APA).^[45]
• 1953 –Harry Stack Sullivan publishedThe Interpersonal Theory of Psychiatry, which holds that an individual's personality is formed by relationships.
• 1954 –Abraham Maslow helped to foundhumanistic psychology, later developingMaslow's hierarchy of needs.
• 1954 –Paul E. Meehl published a paper claiming that mechanical (formal algorithmic) methods of data combination outperform clinical (subjective informal) methods when used to arrive at a prediction of behavior.
• 1954 –James Olds andPeter Milner of McGill University discovered thebrain reward system, involving the brain'spleasure center.
• 1954 –Julian Rotter publishedSocial Learning and Clinical Psychology, foundingsocial learning theory.
• 1954 –Herman Witkin publishedPersonality Through Perception, which claims that personality can be revealed through differences in how people perceive their environment; he went on to develop the Rod and Frame Test (RFT).
• 1954 –Bronisław Malinowski publishesMagic, Science and Religion^[46] onmagical thinking and thepsychology of religion. Earlier, he studied sets ofrituals he referred to as magic,^[47] and distinguished these from purely religious rituals, with the latter's purpose being the coping with one's fundamental human crisis of apparent finiteness/mortality.^[48]
• 1955 –Lee Cronbach publishedConstruct Validity in Psychological Tests, popularizing the concept ofconstruct validity.
• 1955 –J. P. Guilford developed theStructure of Intellect (SOI) theory, which divides human intelligence into 150 abilities along three dimensions, operations, content, and products; it is discredited by the 1990s.
• 1955 –George Kelly foundedpersonal construct psychology.
• 1956 –George Armitage Miller published the paperThe Magical Number Seven, Plus or Minus Two, in which he showed that there is a limit on the amount of information that can bememorized at one time.
• 1956 –Rollo May publishedExistence, promotingexistential psychology.
• 1957 –Leon Festinger published his theory ofcognitive dissonance.
• 1957 –Stanley Smith Stevens publishedStevens' power law.
• 1957 –Eric Berne developedTransactional analysis (TA), in which psychiatry patients can be treated for emotional distresses by analyzing and altering their social transactions.
• 1958 –John Cohen publishedHumanistic Psychology,^[49] the first book on the subject.
• 1958 –Harry Harlow gave the speechThe Nature of Love, summarizing his isolation studies on infant monkeys and rejecting behavioristic and psychoanalytic theories of attachment.
• 1958 –Joseph Wolpe published his theory ofreciprocal inhibition, leading to his theory ofsystematic desensitization for anxieties and phobias.
• 1959 –Viktor Frankl published the first English edition ofMan's Search for Meaning [with a preface byGordon Allport], which provided an existential account of his Holocaust experience and an overview of his system ofexistential analysis calledLogotherapy.
• 1959 –Noam Chomsky published his review ofB.F. Skinner'sVerbal Behavior, an event seen as by many as the start of thecognitive revolution.
• 1959 –George Mandler andWilliam Kessen publishedThe Language of Psychology.
• 1959 –Lawrence Kohlberg wrote his doctoral dissertation, outliningKohlberg's stages of moral development.

• 1960 –John L. Fuller andW. Robert Thompson published the seminal textBehavior Genetics.^[50]
• 1960 –Thomas Szasz inaugurated theanti-psychiatry movement with the publication of his book,The Myth of Mental Illness.
• 1961 –Albert Bandura published theBobo doll experiment, a study of behavioral patterns ofaggression.
• 1961 –Neal E. Miller proposed the use ofbiofeedback to control involuntary functions.
• 1962 –Wilfred Bion presented his unconventional theory of thinking.^[51]
• 1962 –Albert Ellis publishedReason and Emotion in Psychotherapy, describing the theoretical foundations of his therapeutic system known asRational Emotive Behavior Therapy.
• 1962 –George Armitage Miller publishedPsychology, the Science of Mental Life, rejecting the idea that psychology should study only behavior.
• 1962 –Abraham Maslow publishedToward a Psychology of Being, presenting his ideas of self-actualization and the hierarchy of human needs.
• 1962 –Stanley Schachter andJerome Singer proposed thetwo-factor theory of emotion, which considers emotion to be a function of both cognitive factors and physiological arousal; "People search the immediate environment for emotionally relevant cues to label and interpret unexplained physiological arousal."
• 1962 –Silvan Tomkins published volume one (of two) ofAffect Imagery Consciousness, presenting hisaffect theory^[52]
• 1963 –Stanley Milgram published his study of obedience to authority, now known as theMilgram experiment.
• 1964 –Jean M. Mandler andGeorge Mandler publishedThinking: From Association to Gestalt.
• 1964 –Virginia Satir publishedConjoint Family Therapy, the first of several books on family therapy, causing her to become known as the "Mother of Family Therapy"^[53][54]
• 1965 –Anna Freud publishedNormality and Pathology in Childhood: Assessments of Development, presenting the concept ofdevelopmental lines.
• 1965 –William Glasser publishedReality Therapy, describing his psycho-therapeutic model and introducing his concept ofcontrol theory [later renamed toChoice Theory].
• 1965 –Donald Winnicott publishedThe Maturational Process and the Facilitating Environment, which became a main text in clinical psychodynamic developmental psychology.
• 1966 –Nancy Bayley became the first woman to receive the APA Distinguished Scientific Contribution Award for her contribution in developmental psychology.^[55]
• 1966 –Konrad Lorenz publishedOn Aggression, which discusses his hydraulic model of instinctive pressures.
• 1966 –Masters and Johnson publishedHuman Sexual Response.
• 1966 –Julian Rotter published a paper proposing theInternal-External Locus of Control Scale (I-E Scale).
• 1967 –Aaron Beck published a psychological model ofclinical depression, suggesting that thoughts play a significant role in the development and maintenance of depression.
• 1967 –Edward E. Jones andVictor Harris published a paper definingfundamental attribution error, underestimating the effect of the situation in explaining social behavior.
• 1967 –Ulric Neisser foundedcognitive psychology.
• 1968 –George Cotzias developed theL-Dopa treatment for Parkinson's disease.
• 1968 –Mary Main published her hypothesis of a fourthattachment style in children, the insecure disorganized attachment style.^[56]
• 1968 –Walter Mischel published the paper "Personality and Assessment", criticizingGordon Allport's works on trait assessment with the observation that a patient's behavior is not consistent across diverse situations but dependent on situational cues.
• 1968 –DSM-II was published by theAmerican Psychiatric Association.
• 1968 – The firstDoctor of Psychology (Psy. D.) professional degree program in Clinical Psychology was established in the Department of Psychology at theUniversity of Illinois at Urbana–Champaign.
• 1969 – TheCalifornia School of Professional Psychology was established as the first freestanding school of professional psychology.
• 1969 – TheJournal of Transpersonal Psychology was founded byAbraham Maslow,Stanislav Grof, andAnthony Sutich.
• 1969 –John Bowlby published hisattachment theory in the classic bookAttachment and Loss (vol. 1 of 3).
• 1969 –Harry Harlow published his experiment onaffection development inrhesus monkeys.
• 1969 –Joseph Wolpe published theSubjective Units of Distress (Disturbance) Scale (SUDS).
• 1969 –Elisabeth Kübler-Ross publishedOn Death and Dying, presenting theKübler-Ross model, commonly referred to as the five stages of grief.
• 1969 – TheAssociation for Women in Psychology (AWP) was founded, withJoann Evansgardner as the first (temporary) president.^[55]

• 1970 – At an APA Town Hall Meeting, with the support of theAssociation for Women in Psychology,Phyllis Chesler andNancy Henley prepared a statement on APA's obligations to women and demanded one million dollars in reparation for the damage psychology had perpetrated against women's minds and bodies.^[55]
• 1970 – APA Division 29 gives its first Distinguished Professional Award in Psychology and Psychotherapy toEugene Gendlin.
• 1970 – "Critical psychology" became a psychological theoretical field. Klaus Holzkamp, who worked as a professor at theFree University of Berlin, took a central role in definingcritical psychology based on the works ofKarl Marx andAleksei N. Leontiev.
• 1970 –Masters and Johnson publishedHuman Sexual Inadequacy.
• 1971 – TheStanford prison experiment, conducted byPhilip Zimbardo et al. atStanford University, studied the human response to captivity; the experiment quickly got out of hand and was ended early.
• 1971 –Martin Shubik performed thedollar auction, illustrating irrational choices.
• 1971 – In Nov.John O'Keefe andJonathan O. Dostrovsky announced their discovery ofplace cells in the hippocampus.
• 1971 – TheLeibniz Institute for Psychology Information at theUniversity of Trier was founded to publish the PSYNDEX database of references to psychology in the German-speaking world.
• 1972 – TheDunedin Multidisciplinary Health and Development Study commenced, a longitudinal study began, with 96% retention rate as of 2006, unprecedented for a longitudinal study, comparing to 20–40% dropout rates for other studies.
• 1972 –Robert E. Ornstein publishedThe Psychology of Consciousness, about the use of biofeedback et al. to shift mood and awareness.
• 1972 –Gilles Deleuze andFelix Guattari publishedAnti-Oedipus, the first of two-volume workCapitalism and Schizophrenia, criticizing traditional psychoanalysis and its concepts to purpose a new set of theories which they calledschizoanalysis.
• 1972 –Endel Tulving first made the distinction between episodic and semantic memory.
• 1973 –Ernest Becker publishedThe Denial of Death, siding withOtto Rank againstSigmund Freud, claiming that knowledge of one's mortality not sexuality is the basis of character.
• 1973 –Morton Deutsch publishedThe Resolution of Conflict.
• 1973 – Vygotsky Circle neuropsychologistAlexander Luria publishedThe Working Brain, a detailed description with great emphasis on rehabilitation of damage.
• 1973 – TheVail Conference of Graduate Educators in Psychology endorsed thescholar-practitioner training model, and approved theDoctor of Psychology (Psy. D) degree.
• 1973 – Division 35, later theSociety for the Psychology of Women of the APA, was formed, withElizabeth Douvan as the first president.^[55]
• 1973 – TheCommittee on Women in Psychology of the APA was formed, withMartha Mednick as its first chair.^[55]
• 1973 – TheAmerican Psychiatric Association declassified homosexuality as a mental disorder.^[57]
• 1973 – The Caucus of Gay, Lesbian, and Bisexual Members of the American Psychiatric Association was officially founded to advocate to the APA on LGBT mental health issues; in 1985 it changed its name to theAssociation of Gay and Lesbian Psychiatrists.^[58]
• 1973 –Nancy Friday publishedMy Secret Garden: Women's Sexual Fantasies
• 1973 –Timothy Leary publishedNeurologic,^[59] describing theeight-circuit model of consciousness.
• 1974 –Sandra Bem created theBem Sex-Role Inventory.
• 1974 –Robert Hinde publishedBiological Bases of Human Social Behavior, a main text in etological-oriented developmental psychology.
• 1974 –Arnold Sameroff publishedReproductive Risk and the Continuum of Caretaking Causality, introducing thetransactional model of psychology, which became influential.
• 1974 –Alan Baddeley andGraham Hitch of the Univ. of York proposedBaddeley's model of working memory.
• 1974 –Elizabeth Loftus began publishing papers on the malleability of human memory, themisinformation effect, andfalse memory syndrome and its relation torecovered memory therapy.
• 1974 – TheAPA Task Force on Sex Bias and Sex-Role Stereotyping in Psychotherapeutic Practice was appointed.^[55]
• 1975 –Georgia Babladelis became the first editor of thePsychology of Women Quarterly.^[55]
• 1975 –George Mandler publishedMind and Emotion.
• 1975 –Mary Wright became the first chair of the newTask Force on the Status of Women in Canadian Psychology.^[55]
• 1975 –Robert Zajonc published the confluence model, showing how birth order and family size affect IQ.
• 1975 – The first APA-sponsoredPsychology of Women Conference was held.^[55]
• 1975 – The journalSex Roles was founded.^[55]
• 1975 – The first review article on the psychology of women appeared in the women's studies journalSigns, byMary Parlee.^[60]
• 1975 – The first article on the psychology of women was published in theAnnual Review of Psychology.^[55]
• 1975 – The council of representatives of theAmerican Psychological Association (APA) declassified homosexuality as a mental disorder.^[57]
• 1976 –Stanislav Grof founded theInternational Transpersonal Association to promote histranspersonal psychology.
• 1976 –Julian Jaynes publishedThe Origin of Consciousness in the Breakdown of the Bicameral Mind, which coins the termbicameral mind for the brain of humans who lived before about 1,000 B.C.E., whose right side "speaks" in the name of a chieftain or god, and whose left side "listens" and takes orders.
• 1976 –Michael Posner publishedChronometric Explorations of Mind, using the subtractive method ofFranciscus Donders to study attention and memory.
• 1976 – ThePsychology of Women Quarterly was founded.^[55]
• 1977 –Ernest Hilgard proposed thedivided consciousness theory of hypnosis.
• 1977 –Albert Bandura published the bookSocial Learning Theory and an article on the concept ofself-efficacy,A Unifying Theory of Behavioral Change.^[61]
• 1977 –Susan Folstein andMichael Rutter published a study of 21 British twins inJournal of Child Psychology and Psychiatry that reveals a high genetic component in autism.^[62]
• 1977 –Robert Plomin et al. proposed three major ways in which genes and environments act together to shape human behavior, coining the termspassive, active, and evocative gene–environment correlation.^[63]
• 1977 –Andrey Lichko publishedPsychopathies and Accentuations of Character of Teenagers.^[64]
• 1978 – Child psychologistMary Ainsworth published her bookPatterns of Attachment about her work onattachment theory and theStrange Situation Experiment (Protocol).
• 1978 –Paul Ekman published theFacial Action Coding System.
• 1978 –David Premack published the bookDoes the Chimpanzee Have a Theory of Mind?, about his research on mental abilities of monkeys, introducing the termtheory of mind.
• 1978 – The termcognitive neuroscience was coined byMichael Gazzaniga andGeorge Armitage Miller for the effort to understand how the brain represents mental events.
• 1978 –John O'Keefe andLynn Nadel publishedThe Hippocampus as a Cognitive Map.
• 1978 –E.O. Wilson publishedOn Human Nature, considered the first landmark text to deal with what would becomeevolutionary psychology.^{[citation needed]}
• 1978 – The firstCanadian Institute on Women and Psychology pre-convention conference was hosted at the Canadian Psychological Association by IGWAP (Interest Group on Women and Psychology).
• 1978 – The Caucus of Gay, Lesbian, and Bisexual Members of the American Psychiatric Association, (now known as theAssociation of Gay and Lesbian Psychiatrists) successfully petitioned the American Psychiatric Association (APA) to create a task force on lesbian and gay issues; it was elevated to a full standing committee in the APA in 1988.^[58]
• 1979 –Alice Miller publishedThe Drama of the Gifted Child, the first of a series of books criticizing Freud and Jung for blaming the child for the sexual abuse of the parents, which she calls the "poisonous pedagogies".
• 1979 –Urie Bronfenbrenner publishedThe Ecology of Human Development, foundingecological systems theory.

• 1980 – Transgender people were officially classified by theAmerican Psychiatric Association as having "gender identity disorder."^[65]
• 1980 –DSM-III was published by theAmerican Psychiatric Association (APA).
• 1980 –George Mandler publishedRecognizing: The Judgment of Previous Occurrence,^[66] claiming a dual process basis of recognition, prior occurrence and identification.
• 1980 –Robert Zajonc published the paper "Feeling and Thinking: Preferences Need No Inferences", arguing that affective and cognitive systems are largely independent, and that affect is more powerful and important, reviving the study of emotion and affective processes.
• 1981 –Alan P. Bell,Martin S. Weinberg, and Sue Kiefer Hammersmith'sSexual Preference is published. The work later becomes one of the most frequently cited retrospective studies relating to sexual orientation.^[67]
• 1982 –Carol Gilligan publishedIn a Different Voice, a work onfeminist psychology.
• 1982 – The Caucus of Gay, Lesbian, and Bisexual Members of the American Psychiatric Association (APA) was recognized as a representative in the APA assembly, speaking directly on matters of special concern to lesbian and gay members.^[58]
• 1983 –Howard Gardner publishedFrames of Mind, introducing histheory of multiple intelligences.
• 1983 – The Caucus of Gay, Lesbian, and Bisexual Members of the American Psychiatric Association (APA) successfully petitioned the APA to create a task force on psychiatric aspects ofAIDS, which ultimately led to the 1984 publication of two important APA volumesInnovations in Psychotherapy with Homosexuals andPsychiatric Implications of Acquired Immune Deficiency Syndrome.^[58]
• 1983 –W. David Pierce et al. published a paper aboutactivity-based anorexia.^{[citation needed]}
• 1984 –Jerome Kagan publishedThe Nature of the Child, a biological and socially oriented description of the role of temperament in human development.^[68]
• 1984 –Peter Saville published theOPQ Pentagon questionnaire, a psychological personality inventory measuring thefive factor model.
• 1984 –Florence Denmark,Carolyn R. Payton, andLaurie Eyde received the first American Psychological Association (APA) Committee on Women in Psychology Leadership Awards.^[55]
• 1985 –Daniel Stern publishedThe Interpersonal World of the Infant, proposing an extensive mental life in early infancy.
• 1985 –Robert Sternberg proposed histriarchic theory of intelligence^{[citation needed]}
• 1985 –Reuben Baron andDavid A. Kenny published the articleThe Moderator-Mediator Variable Distinction in Social Psychological Research: Conceptual, Strategic, and Statistical Considerations in theJournal of Personality and Social Psychology proposing a distinction of moderating in mediating variables in psychological research.
• 1985 –Simon Baron-Cohen publishedDoes the Autistic Child Have a 'Theory of Mind'? withUta Frith andAlan Leslie, proposing that children with autism show social and communication difficulties as a result of a delay in the development of atheory of mind.
• 1985 – Costa & McRae published theNEO PI_R Five-Factor Personality Inventory, a 240-question measure of thefive factor model^[69]
• 1986 –Albert Bandura publishedSocial Foundations of Thought and Action: A Social Cognitive Theory.
• 1986 –David Rumelhart andJames McClelland publishedParallel Distributed Processing: Explorations in the Microstructure of Cognition.
• 1987 –Erik Erikson publishedThe Life Cycle Completed, expanding onErikson's stages of psychosocial development.
• 1987 –Roger Shepard published theuniversal law of generalization for psychological science.
• 1987 – The diagnostic category of "ego-dystonic homosexuality" was removed from theAmerican Psychiatric Association'sDSM with the publication of theDSM-III-R, though it still potentially remains in the DSM-IV under the category of "sexual disorder not otherwise specified" including "persistent and marked distress about one's sexual orientation".^[70]
• 1988 –Michael M. Merzenich et al. showed that sensory and motor maps in the cortex can be modified with experience, a process calledneural plasticity.^[71]
• 1988 –Claude Steele proposed thetheory of self-affirmation.
• 1989 – PsychophysiologistVladimir Rusalov published firstactivity-specific model of temperament^[72]

• 1990 – On 17 May theWorld Health Organization (WHO) declassified homosexuality as a mental disorder,^[73] launching theInternational Day Against Homophobia and Transphobia.
• 1990 –Leonard Berkowitz published the cognitive neoassociation model of aggressive behavior to cover the cases missed by the frustration-aggression hypothesis.
• 1991 –Steven Pinker proposed his theory on how children acquire language inScience,^[74] later popularized in the bookThe Language Instinct.
• 1991 – The first issue ofFeminism & Psychology was published.^[55]
• 1991- TheAmerican Psychoanalytic Association (APsaA) passed a resolution opposing "public or private discrimination" against homosexuals. It stopped short, however, of agreeing to open its training institutes to these individuals.^[75]
• 1992 – TheAmerican Psychoanalytic Association (APsaA) extended the provisions of its 1991 resolution (see above) to training candidates at its affiliated institutes.^[75]
• 1992 –Jaak Panksepp coined the termaffective neuroscience for the name of the field that studies neural mechanisms of emotion,^[76] and in 1998 published the bookAffective Neuroscience – The Foundations of Human and Animal Emotions^[77]
• 1992 –Sandra Scarr publishedDevelopmental Theories of the 1990s, proposing that genes control experiences, and search and create environments.
• 1992 –Joseph LeDoux summarized and published his research on brain mechanisms of emotion and emotional learning.^[78]
• 1992 – TheAmerican Psychological Association (APA) selectedbehavioral genetics as one of two themes that best represented the past, present, and future of psychology.^[79]
• 1994 –DSM-IV was published by theAmerican Psychiatric Association (APA).
• 1994 –Antonio Damasio publishedDescartes' Error, presenting thesomatic marker hypothesis (SMH) by which emotional processes can guide (or bias) behavior, particularly decision-making.
• 1994 –Richard J. Herrnstein andCharles Murray publishedThe Bell Curve.
• 1994 –Michael Posner andMarcus Raichle publishedImages of the Mind, usingpositron emission tomography (PET) to localize brain cognitive functions.
• 1994 –Esther Thelen andLinda B. Smith publishedA Dynamic Systems Approach to the Development of Cognition and Action, a book on the use of developmental models based on dynamic systems.
• 1994 – A study reports thatmagical thinking emerges more frequently under high-stress (e.g. immediatedeath anxiety) conditions.^[80]
• 1994 – Harvard University professor of psychiatryJohn E. Mack interviews dozens of experiencers of the 1994Ariel School UFO incident, reporting the event to the world,^[81][82] which indicated that the event cannot be dismissed asmass hysteria,^[83] after going on television withalien abductees during the spring of 1994^[84]
• 1995 –Simon Baron-Cohen coined the termmental blindness to reflect the inability of children with autism to properly represent the mental states of others.^[85]
• 1996 –Giacomo Rizzolatti published his discovery ofmirror neurons.^[86]
• 1996 –Amos Tversky definedambiguity aversion, the idea that people do not like ambiguous choices, relating it to comparative ignorance.
• 1997 – TheAmerican Psychoanalytic Association (APsaA) became the first U.S. national mental health organization to support same-sex marriage.^[87]
• 1998 –Martin Seligman establishedPositive Psychology as his main theme when he became President of theAmerican Psychological Association (APA).^[88]
• 1999 –George Botterill publishedThe Philosophy of Psychology,^[89] about how modern cognitive science challenges our common sense self-image.

• 2000 –Alan Baddeley updated his model of working memory from 1974 to include theepisodic buffer as a third slave system alongsidethe phonological loop andthe visuo-spatial sketchpad^[90]
• 2000 –Max Velmans publishedUnderstanding Consciousness, arguing forreflexive monism.
• 2002 –Avshalom Caspi et al. presented a study that was the first to provide epidemiological evidence that a specificgenotype moderates children's sensitivity to environmental insults.^[91][92]
• 2002 –Steven Pinker publishedThe Blank Slate: The Modern Denial of Human Nature, arguing against tabula rasa models of the social sciences.^[93][94]
• 2002 –Daniel Kahneman wonNobel Prize^[95]
• 2007 –George Mandler publishedA History of Modern Experimental Psychology^[96]

• 2010s – As research on the topic accumulates and its usage increases, scientists investigateneuroenhancement – such asnootropics^[97] – regarding psychological mechanisms underlying cognitive functions,neuroethics, effects onmoral decision-making,^[98] public perception, their potential for the treatment of mental diseases, and the potential or ongoing use by professionals or self-administering civilians.^{[99][100][101][102][103][104]}
• 2010s – With the rise of smartphone gaming and a continued large and nearly entirely commercially-drivengaming industry andBig Tech,mobile apps andsocial media are made intentionally addictive using insights from psychology.^[105][106] Research works such asThe Age of Addiction: How Bad Habits Became Big Business propose that the methods of "limbic capitalism"^[107][108] have become substantially more sophisticated.^[108] (see alsobelow)
• 2010s – With increasinglegalization of cannabis within the U.S. and worldwide,chronic effects of various types of cannabis consumption on cognition, along with comparisons of legalization impacts, become a more common focus of psychological research.^{[109][110][111][112][113]}
• 2010s – As digital content becomes more abundant and more immediately available,attention gains a higher value, with theattention economy, where attention is the capital alongside data on consumers, taking shape^[114] as part of "mental capitalism".^[115]
• 2010s – Neuroscience and genetics investigateneurological andheritable factors of intelligence and developneuroimaging intelligence testing, powered by far more extensive data and sophisticated tools.^{[116][117][118][119]}
• 2010 – The draft ofDSM-5 by theAmerican Psychiatric Association (APA) was distributed for comment and critique.
• 2010 –Simon LeVay publishedGay, Straight, and the Reason Why, which in 2012 received the Bullough Book Award for the most distinguished book written for the professional sexological community published in a given year.^[120]
• 2012 – In 2009 America's professional association of endocrinologists established best practices for transgender children that included prescribing puberty-suppressing drugs to preteens followed by hormone therapy beginning at about age 16, and in 2012 theAmerican Academy of Child and Adolescent Psychiatry echoed these recommendations.^[121]
• 2012 – TheAmerican Psychiatric Association issued official position statements supporting the care and civil rights of transgender and gender non-conforming individuals.^[122]
• 2013 – On 2 April U.S. PresidentBarack Obama announced the 10-yearBRAIN Initiative to map the activity of every neuron in the human brain.
• 2013 –DSM-5 was published by the American Psychiatric Association (APA). Among other things, it eliminated the term "gender identity disorder", which was considered stigmatizing, instead referring to "gender dysphoria", which focuses attention only on those who feel distressed by their gender identity.^[123]
• 2014 –Stanislas Dehaene,Giacomo Rizzolatti, andTrevor Robbins, were awarded theBrain Prize for their research on higher brain mechanisms underpinning literacy, numeracy, motivated behaviour, social cognition, and their disorders.^[124]
• 2014 –Brenda Milner,Marcus Raichle, andJohn O'Keefe received theKavli Prize in Neuroscience for the discovery of specialized brain networks for memory and cognition^[125]
• 2014 –John O'Keefe shared theNobel Prize in Physiology or Medicine withMay-Britt Moser andEdvard Moser for their discoveries of cells (Place cell,Grid cell) that constitute a positioning system in the brain.^[126]
• 2015 – The journalPsychology Today announced that it will no longer accept ads for gay conversion therapy, and is deleting medical practitioners who list such therapy in their professional profiles.^{[citation needed]}
• 7 August 2015 – TheAmerican Psychological Association barred psychologists from participating in national security interrogations at sites violating international law.^[127]
• 27 August 2015 – TheReproducibility Project, acrowdsourced collaboration of 270 contributing authors led byBrian Nosek to repeat 100 published experimental and correlational psychological studies, shows thereplication crisis in psychology research,^[128] a term coined in the early 2010s when awareness of the problem was growing.^[129] According to the study published inScience, only 39 of 100 studies published in major psychology journals could be replicated.^[130]
• 2016 – Intensive use of psychological profiling andpsychographicmicrotargeting, as well as voter manipulation – such asInternet manipulation, using insights from psychology and psychological data becomes a worldwide prevalent phenomenon inpolitics ofmajoritarian plain-votes-based democracies.^{[131][132][133][134][135][136][137]} Social media has given rise to new public opinion cues that often have weak links with real public opinion,^[138] part of social media-driven societal and ideological polarisation via "filter bubbles",^[139][140] which becomes an increasingly common topic of psychological research along with conspirational thinking/mentality^[141] andmisinformation-proliferation.
• 13 June 2019 – A study concludes that "spending at least 120 minutes a weekin nature [e.g. via one long or many shorter visits/week] is associated with good health and wellbeing".^[142][143]
• June 2019 — TheWorld Health Organization includedgaming disorder, characterized by problematic or compulsive use of video games, in the11th revision of theInternational Classification of Diseases.^[144][145]
• November 2019 – Researchers report, based on an international study of 27 countries, thatcaring for families is the mainmotivator for people worldwide.^[146][147]

• 2020s – Researchers investigate the impacts of different forms (types or categories) of digital media uses on cognition and the impacts of digital media use(s) on different types of biological cognitive abilities.^{[148][149][150][151][additional citation(s) needed]}
  Further information:Digital media use and mental health § Impact on cognition
• 2020s – Thepandemic COVID-19 and its mitigation have a substantiall toll on mental health worldwide.
  Further information:Impact of the COVID-19 pandemic on neurological, psychological and other mental health outcomes
• With growing awareness and impacts ofclimate change and otherenvironmental issues,ecopsychology increasingly gathers public attention and becomes a more common topic of research^{[additional citation(s) needed]}
  • Studies investigate the psychologicalbenefits of urban green spaces (UGS) in detail, with one 2021 study reporting that higher exposure towoodland urban green spaces orurban forest but not grassland is associated with improvedcognitive development and risks of mental problemsfor urban adolescents.^[152]
  • August 2020 – Areview concludes that "Within a generation, children's lives have largely moved indoors" and that "research indicates thatdirect experiences of nature in childhood contribute to care for nature across the life span."^[153][154]
  • March 2021 – A study concludes that "eco-anger", termed in the style of the recently coined "eco-anxiety" which is reported to be rising, "predicted better mental health outcomes, as well as greaterengagement in pro-climate activism and personal behaviours".^[155]Anger may be "powerful inmotivating people to get involved" and to overcome degrees ofapathy.^[156]
    Further information:Psychological impact of climate change
  • 2020s – Research investigates howwell-being could objectively or effectively be measured forhealth andecological economics.^{[157][158][159][160]}
• 2020s – Accumulating and substantially more sophisticated research, often using large biological datasets, investigate the links ofprobiotics and mental health (psychobiotics) and potential interventions,^[161][162] the links ofnutrition and mental health (nutrition psychology) andpotential recommendations or interventions,^[163] andneurobiological effects of physical exercise that affect mental health.^[164] Moreover, research increasingly begins to investigate potential interventions or modifyable factors inbrain aging.^{[165][166][167][168]}
• 2020s – Research investigates challenges of manipulative choice architectures, false and misleading information and distracting environments and respective potential interventions.^[169][170]
  Further information:Internet manipulation andMisinformation § Online misinformation
• 2020s – In the new field ofneuromarketing, consumers are manipulated with insights from neuroscience and psychology to leadconsumer decision making and behavior.^[171]

2020

• June – Scientists reporting the discovery ofAguada Fénix put forward a theory ofcognitive archaeology whereby communal work of such large projects was important in the initial development of theMaya civilization.^[172]
• November – The firstwhole-genome comparison betweenchimpanzees and bonobos is published and shows genomic aspects that may underlie or have resulted from their divergence andbehavioral differences, including selection for genes related to diet and hormones.^[173]

2021

• July – A study reports thatadolescentloneliness in contemporary schools and depression increased substantially and consistently worldwide after 2012.^[174][175]
• September – Psychologist and behavior geneticistKathryn Paige Harden publishesThe Genetic Lottery: Why DNA Matters for Social Equality, an argument for using genetics to create a just society – including in terms of psychology-related predispositions,^{[176][additional citation(s) needed]} similar to abioethical argument made by Papaioannou in 2013.^[177]
• October – The American Psychological Association releases guidelines for the optimal use of social media in professional psychological practice.^[178]
• December – Inapplied behavioural science, "megastudies" asmeta-analyses are proposed and demonstrated for investigating the efficacy of many different interventions designed in an interdisciplinary manner by separate teams, e.g. to informpolicy.^[179]

2022

• July – Adeep learning system thatlearns intuitive fundamental physics from visual data (of virtual 3D environments) that is based on the violation-of-expectation theory of visual cognition in infants is reported.^[180][181]
• November – A study reports estimated contemporary prevalence and psychological associations withbelief inwitchcraft around the world, which (in their data) varied between 9% and 90% betweennations and is still a widespread element inworldviews globally. It for example shows associations with low "innovative activity", "weak institutions", lowerlife expectancy, lower life satisfaction and highreligiosity.^[182][183]
• November – A study delivers a potential explanation-component for whylearning is often more efficient in children beyond the higher level ofneuroplasticity.^[184][185]

2023

• February – A study hypothesizesmental health awareness efforts (in current forms) or increasingly glamorised and romanticised mental disorderson social media (e.g. quotes about depression on aesthetically appealing backgrounds shared more widely on certain social media – especiallyTikTok^[186]) maycontribute to the recent substantial rise in reported mental health problems by intensifying and over-diagnosing of such.^[187][188] Around 2023, the rapid rise of TikTok prompts extensive research into potential harmful effects of such apps such as higher levels of mental problems correlating with higher levels of usage or addictive elements of this and similar apps.^[189]
• March – Bioengineersshow bodily system changes can induceanxiety, in specific alteredheart rate by itself in risky contexts,^[190][191] after earlier studies also implicatedimmune system elements.^[192][193]

• April – The firstreview ofinterventions against false conspiracy beliefs is published, indicating interventions "that fostered an analytical mindset or taughtcritical thinking skills" are most effective and that preventive action is important.^[194][195]
• June – Atime-use study provides the first comprehensivebird's-eye view, with a "global human day"framework, ofwhat humans currently spend their time on.^[196][197]

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