Psychology Timeline (Modern Period)

Reference: SC: Psychology

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West

1800s

  • c. 1800 – Franz Joseph Gall developed cranioscopy, the measurement of the skull to determine psychological characteristics, which was later renamed phrenology; it is now discredited.
  • 1807 – Georg Wilhelm Friedrich Hegel published Phenomenology 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”.

1810s

1820s

1840s

1850s

1860s

1870s

1880s

1890s

1900s

1910s

1920s

1930s

1940s

1950s

1960s

1970s

1980s

1990s

21st century

2000s

2010s

2020s

2020

2021

  • July – A study reports that adolescent loneliness in contemporary schools and depression increased substantially and consistently worldwide after 2012.
  • September – Psychologist and behavior geneticist Kathryn Paige Harden publishes The 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, similar to a bioethical argument made by Papaioannou in 2013.
  • October – The American Psychological Association releases guidelines for the optimal use of social media in professional psychological practice.
  • December – In applied behavioural science, “megastudies” as meta-analyses are proposed and demonstrated for investigating the efficacy of many different interventions designed in an interdisciplinary manner by separate teams, e.g. to inform policy.

2022

2023

  • February – A study hypothesizes mental health awareness efforts (in current forms) or increasingly glamorised and romanticised mental disorders on social media (e.g. quotes about depression on aesthetically appealing backgrounds shared more widely on certain social media – especially TikTok) may contribute to the recent substantial rise in reported mental health problems by intensifying and over-diagnosing of such. 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.
  • March – Bioengineers show bodily system changes can induce anxiety, in specific altered heart rate by itself in risky contexts, after earlier studies also implicated immune system elements.
  • April – The first review of interventions against false conspiracy beliefs is published, indicating interventions “that fostered an analytical mindset or taught critical thinking skills” are most effective and that preventive action is important.
  • June – A time-use study provides the first comprehensive bird’s-eye view, with a “global human day” framework, of what humans currently spend their time on.

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East

  • 1872–1950 – Sri Aurobindo’s Integral Psychology
    Sri Aurobindo formulates an “integral” psychology that treats consciousness as fundamental, introduces the “psychic being” as evolving soul, and outlines a multi‑tiered model of mind (from physical mind up to supramental) with practices for their transformation.
  • 1905 – First psychology lab in India
    Sir Brojendra Nath Seal establishes what is widely regarded as India’s first psychology laboratory at Calcutta University, initiating institutional Western‑style psychological research in India.
  • 1916 – First Department of Psychology in India
    N. N. Sengupta founds the first Department of Experimental Psychology at the University of Calcutta, explicitly connecting laboratory methods with India’s long introspective traditions.
  • Mid‑20th century – Indian and Buddhist thought enter global psychology
    As humanistic and transpersonal psychologies emerge (c. 1960s), Indian concepts of self‑realization, samādhi, nirvāṇa, and Buddhist meditation are integrated into Western theories of self‑actualization and peak experiences.
  • 1926–2022 – Thich Nhat Hanh and engaged mindfulness
    Thich Nhat Hanh develops a modern, socially engaged Buddhist psychology, articulating the Five and Fourteen Mindfulness Trainings and presenting mindfulness as a whole‑life practice beyond symptom relief.

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Synthesis: Common Patterns and Divergent Paths

Reference: SC: Psychology

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Universal Recognition

All ancient civilizations recognized mental illness as a distinct phenomenon requiring explanation and treatment. Whether called unmada, kuang, até, or mania, each culture developed:

  • Classification systems distinguishing types of mental disturbance
  • Causal theories explaining origins
  • Treatment protocols addressing symptoms
  • Social frameworks for managing affected individuals

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Dual Causation Models

Most traditions maintained parallel supernatural and naturalistic explanations without seeing them as contradictory. Vedic medicine could simultaneously attribute unmada to demonic possession and dosha imbalance. Roman physicians could describe brain-based mechanisms while patients sought divine intercession. This pluralism reflected sophisticated understanding that multiple factors might contribute to mental disturbance.

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The Turn Toward Naturalism

Yet certain pivotal moments accelerated naturalistic thinking:

  • Hippocratic Greece (5th century BCE): Explicit rejection of supernatural causation, brain-centered psychology
  • Buddhist Abhidhamma (3rd century BCE onwards): Phenomenological analysis of mental factors without supernatural agency
  • Asclepiades’ Rome (1st century BCE): Molecular/atomic theory of disease, humane environmental treatment

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Cultural Emphasis Patterns

Eastern traditions (India, China, Buddhism) emphasized:

  • Mind-body integration rather than separation
  • Balance and harmony as health ideals
  • Emotions as physiological forces, not purely psychological
  • Preventive practices (meditation, seasonal regimens, lifestyle)
  • Spiritual/moral dimensions of mental health

Western traditions (Greece, Rome) emphasized:

  • Brain localization of mental functions
  • Material/humoral explanations for psychological phenomena
  • Classification and taxonomy of discrete conditions
  • Clinical observation and detailed symptom description
  • Progressive separation of natural from supernatural causation

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Treatment Sophistication

By the 1st-2nd centuries CE, the ancient world had developed remarkably sophisticated treatment approaches:

  • Ayurvedic psychotherapy (Satwavajaya) using cognitive techniques
  • Chinese acupuncture targeting specific mental-emotional states
  • Buddhist meditation for transforming unwholesome mental factors
  • Roman humane care with music, light, exercise, and supportive environments

Many of these approaches presaged modern treatments: cognitive therapy, environmental modifications, the importance of social support, and recognition that mental and physical health form an integrated whole.

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Limitations and Blind Spots

Ancient understanding also suffered significant limitations:

  • Confusion between neurological conditions (epilepsy, dementia, delirium) and psychiatric conditions (depression, psychosis)
  • Gendered theories often attributing women’s mental illness to “wandering wombs” or hysteria
  • Harmful treatments including bloodletting, violent purges, and occasional use of restraints or isolation
  • Persistent stigma in popular culture despite medical advances
  • Limited understanding of psychotic disorders’ underlying mechanisms

Nevertheless, the intellectual achievements of ancient civilizations in psychology and psychiatry remain profound. They recognized mental illness as a human condition requiring compassionate, systematic response—and in their best moments, developed treatments that honored the dignity and complexity of human consciousness.

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Ancient Rome: Clinical Psychiatry and Humane Treatment

Reference: SC: Psychology

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Progressive Physicians

Asclepiades of Bithynia (124-40 BCE) represents one of history’s most progressive psychiatric reformers. Practicing in Rome, he rejected Hippocratic humoral theory, instead proposing that disease resulted from blockages in the movement of önkoi (imperceptible atomic particles) through theoretical pores in the body—including the brain. This proto-molecular medicine led him to fundamentally different therapeutic approaches.

Most revolutionary were Asclepiades’ humane treatment methods:

  • Fresh air and natural light rather than darkness and dungeons
  • Music therapy using soothing sounds to calm agitated patients
  • Hydrotherapy with therapeutic baths
  • Massage and exercise programs
  • Proper diet to support recovery
  • Pleasant environments conducive to healing

His therapeutic motto—“cito, tuto, jucunde” (safely, swiftly, pleasantly)—stood in stark contrast to the chains, whipping, bloodletting, and forced emetics commonly employed. Asclepiades advocated releasing mentally ill persons from confinement and treating them with dignity, recognizing that the mind could be healed through gentle, supportive interventions.

Celsus (1st century CE) provided the first systematic taxonomy of mental illnesses (genera insaniae) in his De Medicina. He distinguished three primary types:

  1. Phrenitis: acute delirium accompanied by fever, fluctuating pulse rates, and spastic movements—likely organic delirium from physical illness
  2. Mania: characterized by chaotic thoughts, frenzy, anger, and delusions occurring without fever—corresponding to what we would call acute psychosis or manic episodes
  3. Melancholy: persistent sadness, fear, despair, and withdrawal from external reality into an “impenetrable inner world”—encompassing both depression and paranoid or catatonic states we might now associate with schizophrenia

Soranus of Ephesus (1st-2nd century CE), whose work was translated by Caelius Aurelianus, provided detailed clinical descriptions and developed sophisticated treatment protocols including restoration therapy after acute phases subsided.

Galen of Pergamon (129-216 CE) synthesized and expanded Greek medical knowledge, creating a comprehensive system that dominated Western medicine for 1,500 years. Galen:

  • Emphasized the brain’s central role in mental functioning, developing a proto-neurological approach
  • Described how imbalanced humors specifically affected brain operations
  • Recognized anxiety disorders, noting patients with symptoms resembling generalized anxiety or major depression—sweating, indigestion, palpitations, dizziness, insomnia, weight loss
  • Observed that anxiety could “develop into melancholia” when black bile accumulated in the brain, causing delirium, aggression, or suicidal behavior
  • Described brain injuries and their cognitive consequences

Aretaeus of Cappadocia (2nd century CE) provided remarkably modern clinical descriptions, noting melancholic patients’ “aversion to food, despondency, sleeplessness, irritability, and restlessness”. His observations of aura, convulsions, and postictal states in epilepsy closely resemble modern clinical understanding.

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Treatment Modalities

Roman therapeutic approaches combined:

  1. Environmental interventions: well-lit rooms, moderate temperatures, therapeutic gardens
  2. Physical therapies: massage, exercise, hydrotherapy at Roman baths
  3. Dietary regimens: carefully calibrated to restore humoral balance
  4. Pharmacological treatments: various herbs and compounds
  5. Bloodletting, emetics, and purging: to expel excess humors (though now recognized as harmful)
  6. Asclepian temple healing: serene sanctuaries providing relaxation, proper diet, dream interpretation, and social support
  7. Musical therapy: using soothing music therapeutically

Wealthy Roman families sometimes employed personal physicians specializing in mental conditions, providing individualized care in home settings.

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Persistent Popular Beliefs

Despite medical advances, popular Roman culture maintained traditional supernatural explanations. Cicero (106-43 BCE) distinguished between:

  • Insania: a relatively mild condition caused by moral weakness or failure of will
  • Furens: serious, total loss of mental reasoning making individuals unable to function—inflicted by the Furies (Erinyes), three bloodthirsty goddesses who drove mortals mad as divine punishment

The rise of Christianity saw a resurgence of demonic possession theories, temporarily eclipsing the naturalistic medical tradition.

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Ancient Greece: From Divine Madness to Brain Disease

Reference: SC: Psychology

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The Homeric Worldview

In Homer’s epics (8th century BCE), mental illness bore the unmistakable stamp of divine intervention. Até (madness, delusion, reckless behavior) descended upon individuals as an “invisible fluid” sent by angry deities or malevolent demons (alástores). When Odysseus or Agamemnon acted irrationally, Homer attributed this not to psychological or physiological causes but to external demonic forces clouding judgment.

The Homeric conception located the psychic center in the heart (kradiē or ētor) rather than the brain, viewing it as the seat of emotions and cognitive functions. No clear separation existed between psychic and somatic conditions—both belonged to the same continuum of divine influence upon the body.

Greek tragedy perpetuated these themes. Euripides and Aeschylus depicted Orestes suffering terrifying hallucinations, wild ravings, and suicidal despair after matricide—tormented by the Furies (Erinyes), avenging goddesses who drove mortals to madness as divine punishment. Popular treatments involved katharmos (purification) to remove religious pollution (miasma) and sacrifices to appease offended deities.

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The Hippocratic Revolution

The Hippocratic Corpus (5th-4th century BCE), particularly the treatise “On the Sacred Disease” concerning epilepsy, marked one of history’s most consequential intellectual revolutions. The author (traditionally Hippocrates) began with a direct challenge:

“I am about to discuss the disease called ‘sacred.’ It is not, in my opinion, any more divine or more sacred than other diseases, but has a natural cause, and its supposed divine origin is due to men’s inexperience and to their wonder at its peculiar character”.

This represented a fundamental shift: mental and neurological disorders arose from natural, not supernatural, causes. Epilepsy wasn’t divine punishment but a disease of the brain. The Hippocratic physicians argued that:

  • The brain is the seat of consciousness, emotion, sensation, pleasure, pain, thought, and madness
  • Mental illness results from material causes—specifically imbalances in bodily fluids
  • Treating madness as supernatural pollution represents “ignorance and wonder,” not medical knowledge

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The Humoral Theory

Hippocratic medicine developed the humoral theory, which dominated Western medicine for two millennia. Health depended on proper balance among four bodily fluids:

  • Blood (sanguine temperament): optimistic, cheerful
  • Phlegm (phlegmatic temperament): calm, composed
  • Yellow bile (choleric temperament): irritable, angry
  • Black bile (melancholic temperament): sad, fearful

Melancholia (literally “black bile”) became the paradigmatic mental illness—what we would call severe depression, attributed to excess black bile accumulating in the brain. Hippocratic texts described symptoms including persistent sadness, anxiety, despondency, sleeplessness, and social withdrawal.

Mania represented the opposite extreme—excessive excitement, delusions, agitation, and sometimes violence, associated with yellow bile imbalance. The physician Celsus described manic patients as those who “laugh and are cheerful without cause” and sometimes exhibit “incautious rage”.

Phrenitis—acute mental disturbance with fever, roughly corresponding to delirium—was distinguished from chronic conditions, showing awareness that temporary altered states differed from persistent mental illness.

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Philosophical Contributions

Plato (427-347 BCE) developed a sophisticated psychology in the Republic and Timaeus. His tripartite soul comprised:

  • Logistikon (reason): the thinking part that loves truth
  • Thymoeides (spirit): the source of anger and spirited emotions
  • Epithymetikon (appetite): the seat of physical desires and pleasures

Mental health consisted in proper hierarchy—reason governing spirit and appetite—just as justice in the state requires each class to fulfill its proper function. Plato explicitly linked morality and mental health, arguing that “nobody is wicked because of his own choice but because of the ‘evil condition’ of the body and because of bad education”. This didn’t excuse immoral behavior but recognized it as “contrary to nature and thus treatable”.

Aristotle (384-322 BCE) applied his hylomorphism to psychology: the soul stands to the body as form to matter. Unlike Plato’s dualism, Aristotle insisted the soul cannot exist without the body. He described the melancholic temperament—those dominated by black bile—as emotionally unstable, impulsive, prone to vivid dreams and prophetic visions, sleeping little, eating much yet remaining thin. The pseudo-Aristotelian Problems suggested melancholics were predisposed to madness because of black bile’s “precarious nature”.

The Stoics contributed the concept of ataraxia (undisturbed tranquility) achieved through internal control over reactions to external events—presaging cognitive therapy. 

The Epicureans argued that anxiety and fear arose from misunderstanding nature, particularly regarding death and divine punishment, suggesting education as treatment.

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Buddhism: The Phenomenology of Mental Defilement

Reference: SC: Psychology

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Citta, Cetasikas, and the Stream of Consciousness

Buddhist psychology, systematized in the Abhidhamma (Abhidharma), developed a radically different yet equally sophisticated understanding of mind and mental illness. Rather than locating mind in a physical organ, Buddhism conceived citta (consciousness/mind) as an “ever-flowing stream” continuously changing from conception to death and continuing into subsequent lives.

Accompanying each moment of citta were cetasikas (mental factors)—52 distinct psychological qualities that determine the ethical character and phenomenological texture of consciousness. These include:

Seven universal cetasikas present in every moment of consciousness: contact, feeling, perception, volition, one-pointedness, life faculty, and attention

Thirteen particulars that can be wholesome, unwholesome, or neutral depending on context

Twenty-five beautiful (wholesome) cetasikas including compassion, loving-kindness, mindfulness, and wisdom

Fourteen unwholesome cetasikas that constitute the essence of mental illness

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The Nature of Mental Illness

In perhaps the most radical conception in ancient psychology, Buddhism equated all mental defilement with mental illness. The Buddha taught: “Those beings who admit to being freed from mental illness even for a moment are difficult to find in the world, except those who have destroyed the contaminants”. From this perspective, only fully enlightened beings (arahants) are truly mentally healthy; everyone else suffers from varying degrees of mental illness.

Mental illness manifests through unwholesome states (akusala dhamma)—mental factors that are (1) mentally unhealthy, (2) morally blameworthy, (3) unskillful, and (4) productive of painful results. These states arise conditionally and are impermanent, making them treatable.

The fourteen unwholesome cetasikas divide into two categories:

Four universals appearing in all unwholesome consciousness:

  • Moha (delusion/ignorance)
  • Ahirika (shamelessness)
  • Anottapa (fearlessness of wrongdoing)
  • Uddhacca (restlessness/agitation)

Ten occasionals appearing in specific unwholesome states:

  • Lobha (greed), dosa (hatred)—the two primary unwholesome roots
  • Ditthi (wrong view), mana (conceit)
  • Issa (envy), macchariya (miserliness/pretense)
  • Kukkucca (worry), vicikiccha (doubt arising from temptation)
  • Thina (sloth), middha (torpor)—together constituting one of the Five Hindrances

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Madness and Possession

Beyond this universal “metaphorical-evaluative” sense of mental illness, Buddhist texts also recognized literal pathological madness. The Pali Jataka commentary provides an eightfold classification of madness types, acknowledging both naturally-caused conditions and possession—not just by demons but by Mara, understood simultaneously as a deity and a phenomenological reality.

Possession traditions existed across Buddhist cultures. Tibetan Buddhism recognized dön zhugs pa (possession by grahas)—spirits that could enter practitioners during intense meditation, especially in states of deep samadhi. The Shurangama Sutra describes fifty types of mental demons that can attack practitioners who cling to unusual experiences or visions during meditation, potentially causing insanity with extreme emotional swings between joy, sadness, and mania.

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Treatment and Practice

Buddhist treatment focused on cultivating wholesome cetasikas while eliminating unwholesome ones through the Noble Eightfold Path:

  • Right View as the foundation, correcting the fundamental delusion that fuels all mental defilement
  • Meditation practice—but with significant caveats about the risks of improper practice leading to possession or psychotic breaks
  • Moral conduct to eliminate shamelessness and fearlessness of wrong
  • Mindfulness to observe mental states without attachment
  • Mantra recitation—considered safer than visualization practices that can invite possession
  • Taking refuge in the Three Jewels (Buddha, Dharma, Sangha) as protection against negative entities

The tradition emphasized that those with “firm conviction” in the Dharma and who practice daily merit dedication cannot be harmed by demons. Nevertheless, practitioners were warned against clinging to visions or unusual experiences, as “if one claims to see Buddhas and bodhisattvas, these are demons”—meaning either literal entities or subjective delusions.

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