Definitions of abnormality: the history of abnormality
This section opens clinical psychology, the first A Level topic of Unit 4, and assumes the AS knowledge from Units 1 and 2: research methods, reliability and validity, ethics, and the biological and learning approaches.
Everything in this notes unit (definitions of abnormality, the classification systems, the debates in diagnosis and Rosenhan's classic study) is examined on Unit 4 (WPS04/01), mostly as short items in Section A; it also feeds the issues-and-debates essay in Section E.
For this first part of the topic you need to know: "Definitions of abnormality: the history of abnormality; statistical infrequency definition; failure to function adequately including Rosenhan and Seligman, 1989."
This section teaches the history.
The next two sections teach the two definitions.
- The paper. WPS04/01 lasts 2 hours for 96 marks in five sections: A Clinical psychology (32, short items), B one Evaluate (16), C Psychological skills (20), D one key-question Discuss (8), E one Assess (20). Allow about 1.25 minutes per mark.
- Section A's usual shape is four clusters: a study cluster of about 7 marks (often Rosenhan), a clinical research-methods scenario of about 10, a short patient scenario of about 4 (often on diagnosis), and a content cluster of about 11. One series broke this into five smaller questions, one of them on culture in diagnosis.
- Command words used in Unit 4: Give, State, Identify (1); Describe (2, 3 or 4); Explain (2 for one point, 4 for two, 6 for three); Analyse (6); Calculate (1 or 4); Draw (3); Determine and Justify (1); Evaluate (16, Section B only); Discuss (8, Section D only); Assess (20, Section E only). Never Define, Compare, Suggest or To what extent on this paper; "State what is meant by" stands in for a definition.
- This notes unit's weight. From January 2024 to June 2025 it carried about a tenth of all Unit 4 marks, every one in short items: Rosenhan's aim, data, admission procedure and evaluation; statistical infrequency; failure to function; reliability, validity and culture in diagnosis.
- Explain always means a point plus its justification: the second mark (AO3) is the reason or evidence, and it is the mark most often lost.
The idea: who decides what is abnormal?
Sana, a 17-year-old in Lahore, has stopped sleeping more than four hours a night.
She checks that the gas is off thirty times before she can leave the house, and is late for college most days.
Her grandmother thinks she is under the evil eye.
Her teacher thinks she is lazy.
Her cousin, a medical student, thinks she has an anxiety disorder and should see a doctor.
Three people look at the same behaviour and reach three different explanations, and each explanation leads to a different response: a prayer, a punishment or a treatment.
That is the question at the heart of this topic.
What makes behaviour "abnormal", who has the right to decide, and what follows from the label? The history of abnormality shows that every society has answered this question, that the answer has changed many times, and that the answer chosen always shaped how people were treated.
Why study the history?
Your syllabus asks for the history first because it shows two things you will use in every later section.
1. Definitions are not fixed facts. What counts as a disorder has been decided by the beliefs, science and values of each period. Some behaviours once called disorders are now seen as normal, and some behaviours once ignored are now diagnosed.
2. The explanation chosen decides the treatment. If abnormality is caused by spirits, the response is ritual; if by a sick brain, it is medicine; if by a harsh environment, it is care and therapy. Many past treatments were cruel because the explanation behind them was wrong.
The diagram below sets the main periods in order.
The main periods
Period
How abnormality was explained
How people were treated
Ancient world
Supernatural: possession by spirits or punishment by gods. Hippocrates (Greece, around 400 BCE) argued for natural causes: an imbalance of four bodily fluids, the four humours (blood, phlegm, yellow bile and black bile); too much black bile caused melancholia
Rituals and exorcism. Some Neolithic skulls show trephining (a hole cut in the skull), which some researchers interpret as releasing spirits, though its purpose is uncertain. Humoral medicine used diet, rest and bloodletting
Middle Ages to 1700s
In parts of Europe, unusual behaviour was linked to witchcraft and the devil; the Malleus Maleficarum (1487) was a handbook for identifying witches
Trials and execution of some people who were probably mentally ill. From the late Middle Ages, asylums confined people: Bethlem in London (later called "Bedlam") housed people with mental illness from the 1400s and became notorious for chains and public viewing
1790s: moral treatment
Mental illness as a condition that humane care could improve
Philippe Pinel is traditionally credited with removing patients' chains in Paris in the 1790s; William Tuke opened the York Retreat in 1796, using kindness, work and a calm setting
Late 1800s: the medical model
Abnormality as illness with physical causes, to be classified like any disease
Emil Kraepelin grouped symptoms into named disorders, separating dementia praecox (later called schizophrenia by Eugen Bleuler) from manic-depressive illness. Large state asylums grew. Freud's psychodynamic view (Unit 2) offered a psychological alternative
1950s to 1970s
Biological and psychological explanations side by side
The first antipsychotic, chlorpromazine, was introduced in 1952, the same year as DSM-I. Drugs made it possible to close many large asylums (deinstitutionalisation) and treat people in the community
1970s to today
Criteria-based diagnosis; biological, psychological and social factors combined
Rosenhan (1973) challenged whether psychiatrists could tell the sane from the insane. DSM-III (1980) introduced explicit criteria to make diagnosis reliable. Today DSM-5 and ICD-11 are used, with therapies such as CBT alongside drugs
The picture below shows the kind of setting moral treatment aimed for, in place of chains and locked cells.
What the history shows about definitions
The clearest lesson is that definitions of abnormality are culturally and historically relative.
Two examples make this vivid.
- Drapetomania. In 1851 the American physician Samuel Cartwright described "drapetomania", a supposed mental illness that made enslaved people run away. Wanting freedom was turned into a symptom. This shows how a definition of abnormality can be used for social control: to label people whose behaviour challenges those in power.
- Homosexuality. Homosexuality was listed as a mental disorder in DSM until the American Psychiatric Association voted to remove it in 1973, and it was removed from the ICD when ICD-10 was endorsed in 1990. Behaviour had not changed; social values and the evidence had.
So when you meet a definition, ask: who wrote it, when, and whose norms does it reflect? That question underlies the cultural issues in diagnosis later in this unit.
Why it works this way. A definition of abnormality needs a reference point, something "normal" to compare behaviour with.
Each period took its reference point from what it already believed: religious teaching, the body's balance, the standards of polite society, or the average of a population.
When the reference point changes, the boundary of abnormality moves with it.
From history to the two definitions you must know
Modern psychology has tried to replace opinion with clearer standards.
Your syllabus names two definitions, taught in the next two sections:
- Statistical infrequency: abnormal behaviour is behaviour that is statistically rare, far from the average of the population. Its reference point is the numbers.
- Failure to function adequately, including Rosenhan and Seligman (1989): abnormal behaviour is behaviour that stops a person coping with everyday life, judged by a set of features such as suffering and maladaptiveness. Its reference point is the person's daily life.
Each fixes some of the history's problems and keeps others.
Neither is enough alone, which is why the classification systems (DSM and ICD) combine ideas from both: a diagnosis needs symptoms that are unusual and that cause distress or impairment in functioning.
Not examined, for interest: other textbooks add "deviation from social norms" and "deviation from ideal mental health" (Jahoda, 1958).
They are not on your syllabus, but drapetomania is a good illustration of why defining abnormality by social norms is risky.
Links. Social control and the use of psychological knowledge in society are Section E debates (notes unit I3): the history gives you evidence for both.
Freud's psychodynamic approach (notes unit D3) belongs to the late 1800s and early 1900s in this history.
Antipsychotic drugs and deinstitutionalisation return in schizophrenia (notes unit H2).
- Abnormality: behaviour or experience that differs from what is considered normal, judged against a reference point such as statistical frequency or adequate everyday functioning.
- Medical model: the view that mental disorders are illnesses with physical causes, which can be diagnosed from symptoms and treated, often with drugs.
- Moral treatment: an approach from the 1790s that replaced restraint with humane care, routine and work in calm surroundings.
- Deinstitutionalisation: the closing of large psychiatric hospitals from the 1950s onwards, with people treated in the community, helped by new drugs.
- Cultural relativism: the idea that what counts as normal or abnormal depends on the culture and period in which behaviour is judged.
Describe how explanations of abnormality have changed over time.
(4)
Top answer (4 of 4).
1. In the ancient world abnormality was often explained by the supernatural, though Hippocrates proposed an imbalance of four humours such as black bile in melancholia. (AO1)
2. In medieval Europe some unusual behaviour was linked to witchcraft, and from the late Middle Ages people were confined in asylums such as Bethlem. (AO1)
3. In the 1790s moral treatment, associated with Pinel and Tuke's York Retreat, replaced chains with humane care. (AO1)
4. In the late 1800s Kraepelin's medical model classified disorders by their symptoms, which led to the modern manuals, DSM and ICD, and to drug treatment from the 1950s. (AO1)
Why it scores 4: four distinct periods, each with an accurate, specific detail (a name, a date or a treatment).
Describe on content is AO1, one mark per developed point, with no evaluation needed.
Weaker answer (2 of 4): "People used to think mental illness was caused by demons, but now we know it is caused by the brain and we use drugs."
Two points, both thin, and "caused by the brain" is not accurate as a summary of modern psychology, which combines biological, psychological and social causes.
Chidi is a psychology student in Lagos.
He reads that homosexuality was listed as a mental disorder in DSM until 1973 and asks his tutor how a disorder can simply disappear.
Explain one reason why Chidi's example shows that definitions of abnormality can change.
(2)
Top answer (2 of 2): The behaviour Chidi read about did not change between the editions, only the American Psychiatric Association's vote in 1973 did (AO2), so what counts as abnormal was decided by the social values and evidence of the time, which shows definitions are culturally and historically relative, not fixed facts (AO3).
Not credited (0 of 2): "Definitions of abnormality change over time because society changes."
It is true, but nothing in it comes from Chidi's example: no reference to the 1973 removal, so it is generic and scores 0 on a scenario item.
Explain one weakness of seeing abnormality as a medical illness, using the history of abnormality.
(2)
Top answer (2 of 2): Under the medical model a label such as "drapetomania" could be given a scientific-sounding name and treated as a disease (AO1), which shows that a medical label can hide a social judgement and be used to control people whose behaviour is unwelcome, so the model is not as objective as it claims (AO3).
The history has not yet been set as its own item, so it is most useful as evidence: in a Section E Assess on social control or on how psychology has changed over time, drapetomania, homosexuality's removal from DSM in 1973 and deinstitutionalisation after chlorpromazine are concrete, dated examples.
If a Describe does ask for the history, give one period per mark, each with a name, date or treatment.
- Treating history as "they were ignorant, we are right". Many past ideas were reasonable for their evidence, and some modern categories may also change. The examinable point is that definitions are relative.
- Vague periods. "In the past people thought it was demons" earns little; name a period, a person or a treatment.
- Mixing up Bedlam and moral treatment. Bethlem ("Bedlam") stands for confinement and restraint; Pinel and Tuke stand for the humane reform that followed.
- Claiming drugs alone emptied the asylums. Chlorpromazine made community care possible, but deinstitutionalisation also followed changes in law, cost and attitudes.
Check your understanding
1. State what is meant by 'moral treatment'. (1) Total [1]
2. Give one example of a behaviour once classed as a mental disorder that is no longer classed as one. (1) Total [1]
3. Describe how the medical model changed the treatment of people with mental illness. (3) Total [3]
4. Meera, a nurse in Kerala, says her grandfather's generation took people with severe mental illness to a temple for healing, while her hospital now uses antipsychotic drugs and therapy. Explain two reasons why the explanation of abnormality used in each of Meera's examples would affect how people were treated. (4) Total [4]
5. A student writes: "Definitions of abnormality are scientific facts, so they never change." Explain one reason why this student is wrong. (2) Total [2]
6. Evaluate the medical model as a way of defining and treating abnormality. (16) Total [16]
Answers
1. An approach from the 1790s, linked with Pinel and Tuke's York Retreat, that replaced chains and restraint with humane care, routine and work (AO1 1).
2. Homosexuality, removed from DSM in 1973 (AO1 1). Also credited: drapetomania (described in 1851, never a valid disorder).
3. Three developed points, for example: disorders were classified into named illnesses by their symptoms, following Kraepelin (AO1 1); people were treated as patients in hospitals by doctors, not punished (AO1 1); from 1952 drugs such as chlorpromazine reduced symptoms, so many large asylums could close and people were treated in the community (AO1 1).
4. Two points, each tied to Meera's examples, then why:
- Her grandfather's generation took people to a temple, which fits a spiritual explanation (AO2 1), and if abnormality is believed to come from spiritual causes, the logical response is prayer or ritual, not medicine (AO3 1).
- Her hospital uses antipsychotic drugs, which fits the medical model's view that symptoms come from brain chemistry (AO2 1), so treatment targets the body, for example by blocking dopamine receptors, and therapy is added because psychological factors are now also seen as causes (AO3 1). Generic answers that describe the history without Meera's temple or hospital score 0.
5. Homosexuality was classed as a mental disorder in DSM until 1973, when the American Psychiatric Association removed it although the behaviour itself had not changed (AO1), so definitions depend on the values and evidence of a period and are revised, which shows they are not fixed facts (AO3).
6. Plan for a 16-mark Evaluate (AO1 6, AO3 10). AO1: abnormality as illness with physical causes (Kraepelin's classification; symptoms grouped into disorders; DSM and ICD); treatment by drugs such as chlorpromazine from 1952. AO3 chains: humane compared with what came before, since patients were treated as ill, not as witches, so blame fell; classification lets clinicians agree on a diagnosis and research treatments, and drugs allowed deinstitutionalisation; but labels can be used for social control (drapetomania; homosexuality until 1973), so medical language can hide value judgements; Rosenhan (1973) showed staff reading normal behaviour as symptoms once a label was given, so the model can distort perception; it is reductionist, ignoring social causes such as poverty or family stress that therapies such as CBT and family therapy address; drugs reduce symptoms but do not always treat causes. Conclusion: the medical model brought a more humane and testable approach and effective drug treatment, but on its own it risks treating social judgements as illness, so it works best within a model that adds psychological and social causes. Level 4 (13-16) needs chains on both sides and a balanced conclusion; a description of history with "so it is good" stays in Level 2.