Definitions of Abnormality

One of the most fundamental questions in psychopathology is: how do we define "abnormal" behaviour? There is no single, universally accepted definition of abnormality. Instead, psychologists use several different approaches, each with its own strengths and limitations. Understanding these definitions and being able to evaluate them critically is a core requirement of AQA A-Level Psychology.

Key Definition: Abnormality in psychology refers to behaviour, thoughts, or feelings that deviate from what is considered normal, acceptable, or healthy. Different definitions emphasise different criteria, and no single definition is sufficient on its own.

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1. Statistical Infrequency

The statistical infrequency definition identifies abnormality as behaviour that is statistically rare — that is, behaviour that falls outside the range of what is typical for the population. Any behaviour that deviates significantly from the statistical average is considered abnormal.

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