You are viewing a free preview of this lesson.
Subscribe to unlock all 10 lessons in this course and every other course on LearningBro.
What does it mean to be "mentally healthy" or "mentally ill"? Defining abnormality is one of the most challenging tasks in psychology. There is no single definition that psychologists universally agree on — each approach has strengths and limitations. Understanding these definitions is essential for GCSE Psychology.
Statistical infrequency defines abnormality as behaviour or characteristics that are statistically rare — they deviate significantly from the average (mean) for the population.
In a normal distribution, most people cluster around the average, with fewer people at the extremes. Any characteristic that falls outside the normal range (typically the top or bottom 2.5%) is considered statistically abnormal.
Example: An IQ score below 70 (bottom 2.5% of the population) is considered statistically abnormal and may indicate an intellectual disability.
| Strength | Weakness |
|---|---|
| Objective — based on measurable data | Does not distinguish between desirable and undesirable abnormality — an IQ of 150 is also statistically rare but is not a problem |
| Clear cut-off points — can identify when someone deviates from the norm | Not all statistically rare behaviours are problematic — being left-handed is rare but not abnormal |
| Useful for diagnosis when combined with other criteria | Does not account for cultural differences — what is rare in one culture may be common in another |
Deviation from social norms defines abnormality as behaviour that violates the unwritten rules and expectations of a society.
Social norms are the implicit rules about how people should behave in a given society. Behaviour that breaks these norms is seen as abnormal.
Example: Talking loudly to yourself in public may be seen as deviating from social norms in some cultures.
| Strength | Weakness |
|---|---|
| Takes social context into account | Social norms vary between cultures — what is abnormal in one culture may be normal in another |
| Can identify behaviour that causes distress to others | Social norms change over time — definitions of abnormality based on social norms are historically relative (e.g. homosexuality) |
| Useful in identifying behaviours that need intervention | Can be used to control or punish people who are simply different, rather than genuinely disordered |
| Eccentric behaviour may be labelled as abnormal when it is harmless |
Failure to function adequately defines abnormality as the inability to cope with everyday life — when a person's behaviour or mental state prevents them from functioning in daily activities.
Signs of failure to function adequately include:
| Strength | Weakness |
|---|---|
| Focuses on the individual's experience — recognises personal suffering | Some people with mental health problems may still function adequately (e.g. a person with depression who continues to work) — they would not be identified |
| Recognises that abnormality involves real difficulties in daily life | Some people may choose not to conform to social expectations without being mentally ill (e.g. homeless people who choose to live that way) |
| Is person-centred — focuses on whether the individual needs help | Who decides what "adequate functioning" means? This is subjective |
Deviation from ideal mental health defines abnormality as the absence of signs of good mental health. Marie Jahoda (1958) identified six criteria of ideal mental health:
| Criterion | Description |
|---|---|
| Self-actualisation | Achieving your full potential |
| Autonomy | Being independent and self-reliant |
| Accurate perception of reality | Seeing the world as it really is |
| Environmental mastery | Being able to meet the demands of any situation |
| Resistance to stress | Having effective coping mechanisms |
| Positive self-attitudes | Having good self-esteem and a positive self-image |
The more of these criteria a person lacks, the more "abnormal" they are considered to be.
| Strength | Weakness |
|---|---|
| Positive approach — focuses on health rather than illness | Sets an unrealistically high standard — very few people would meet all six criteria, so most people would be classified as abnormal |
| Provides a comprehensive picture of mental health | The criteria are culturally biased — they reflect Western, individualist values (e.g. autonomy may not be valued in collectivist cultures) |
| Considers multiple aspects of mental health | The criteria are difficult to measure objectively |
The World Health Organisation (WHO) defines mental health as "a state of well-being in which an individual realises their own abilities, can cope with the normal stresses of life, can work productively and fruitfully, and is able to make a contribution to their community".
This is a positive definition — it treats mental health as more than the absence of mental illness. It aligns with Jahoda's ideal mental health approach and is used in UK public-health planning by the NHS, Department of Health and Social Care, and charities such as Mind.
However, as with Jahoda's criteria, the WHO definition has been criticised for:
Despite these criticisms, the definition usefully reframes mental health as something everyone can promote, not just a label for those who are ill.
flowchart TD
A[WHO definition: Mental health] --> B[Realising own abilities]
A --> C[Coping with normal life stresses]
A --> D[Working productively]
A --> E[Contributing to community]
F[Four definitions of abnormality] --> G[Statistical infrequency]
F --> H[Deviation from social norms]
F --> I[Failure to function adequately]
F --> J[Deviation from ideal mental health: Jahoda]
J -.-> A
Debates over defining abnormality are not purely academic — definitions shape:
A reflective psychologist therefore treats definitions as working tools that must be applied carefully and updated as understanding develops.
A consistent challenge across the four definitions is culture. Behaviour considered abnormal in one culture may be entirely normal in another:
These examples show why clinicians and researchers are encouraged to use culturally informed assessment, consider multiple frameworks, and involve people from the relevant community when making diagnostic decisions. UK mental-health services increasingly work with interpreters, cultural advocates and community organisations to reduce the risk of culturally biased judgement.
Aim: To investigate whether mental health professionals could reliably distinguish "normal" from "abnormal" behaviour, and to examine how labels of abnormality affect treatment in psychiatric hospitals. The study directly challenged the validity of abnormality-based diagnostic categories used at the time.
Procedure: Eight mentally healthy "pseudopatients" — including Rosenhan himself, a psychologist, a paediatrician, a housewife and a student — presented themselves at twelve US psychiatric hospitals. Each reported a single symptom: hearing an unfamiliar voice saying words such as "empty", "hollow" and "thud". Otherwise they gave truthful life histories and answered questions honestly. Once admitted, they behaved entirely normally and said the voices had stopped. They recorded staff behaviour, interactions and their own experiences until discharged.
Findings: All eight pseudopatients were admitted; seven were diagnosed with schizophrenia. Hospital stays lasted between 7 and 52 days (average 19). Despite behaving normally, none was detected as sane by staff — though other patients frequently voiced suspicions. Normal behaviours (such as note-taking) were reinterpreted in the notes as pathological ("patient engages in writing behaviour"). On discharge, all were labelled "schizophrenia in remission" rather than misdiagnosed.
Conclusion: Diagnoses based on prevailing definitions of abnormality lacked validity — once the "sick" label was applied, professionals saw only confirming evidence (a form of diagnostic bias). Rosenhan concluded that we cannot reliably distinguish the sane from the insane in the context of psychiatric hospitals, and that labels can have serious and lasting effects on how people are perceived and treated.
GRAVE evaluation:
Misconception: "Abnormal behaviour always means someone is mentally ill."
Definitions such as statistical infrequency and deviation from social norms can classify behaviours as "abnormal" that are simply unusual, creative or culturally different — left-handedness, bilingualism, or belonging to a minority faith. Clinical judgements about mental health require more than rarity or difference: they consider distress, impairment and duration, and are made by qualified professionals using frameworks like ICD-11. Campaigns from the NHS, Mind and the Samaritans (116 123) stress that difference is not the same as disorder.
Question: Discuss definitions of abnormality. [9 marks]
Grade 3–4 response:
Psychologists define abnormality in different ways. Statistical infrequency means behaviour that is rare. Deviation from social norms means behaviour that breaks the rules of society. Failure to function adequately means you can't cope with daily life. Ideal mental health means you don't fit Jahoda's criteria. Each one has strengths and weaknesses. Some ideas are more useful than others.
Lists the four definitions but without detail, examples or developed evaluation.
Grade 5–6 response:
Statistical infrequency defines abnormality as behaviour that is statistically rare, for example an IQ below 70. Its strength is being objective, but it does not distinguish desirable rarity (like high IQ). Deviation from social norms captures behaviour that breaks social rules, but norms change over time — homosexuality was classed as a disorder in the DSM until 1973. Failure to function adequately focuses on whether someone can cope with daily life, which is person-centred but subjective. Jahoda's ideal mental health gives a positive picture with six criteria (autonomy, self-actualisation, etc.) but sets an unrealistic standard and is culturally biased towards Western values.
Uses examples, provides one point per definition and offers light evaluation.
Grade 7–9 response:
The four definitions — statistical infrequency, deviation from social norms, failure to function adequately and deviation from ideal mental health — capture different facets of what it means for behaviour to be "abnormal". Statistical infrequency offers an objective threshold but blurs rarity with pathology: IQ of 150 is statistically rare yet desirable. Deviation from social norms is culturally and historically contingent — homosexuality's removal from the DSM in 1973 and the ongoing removal of cultural bias from ICD-11 illustrate how norms drift. Failure to function adequately centres lived experience and distress, which aligns with NHS practice, but risks subjectivity about what "adequate" means. Jahoda's ideal mental health articulates a positive model but sets an unattainable standard and reflects Western individualism. Integrating this critique with Rosenhan's (1973) demonstration that labels powerfully shape perception suggests no single definition suffices; instead clinicians draw on multiple criteria — distress, impairment, duration and cultural context — as recognised in ICD-11. A sophisticated evaluation therefore treats the four definitions as complementary lenses whose value depends on purpose: research versus clinical diagnosis versus public-health planning.
Demonstrates integration across definitions, a named study, classification systems and developed evaluation — top band.
This content is aligned with the AQA GCSE Psychology (8182) specification, Paper 2: Social context and behaviour — Psychological problems. For the most accurate and up-to-date information, please refer to the official AQA specification document.