Outline; deviation from social norms
Socially unacceptable behaviour is seen as abnormal e.g. paedophilia. Social norms are accepted ways of behaving within a society. They are the unwritten rules that members of a society regard as being normal and acceptable, and any deviation from them can be regarded as abnormal behaviour. Examples include ways of dressing, such as women wearing feminine clothing and men wearing masculine clothing, not appearing naked in public, saying 'please' and 'thank you', opening doors for women and elderly people etc. Social norms may, however, vary between cultures.
The problem with defining abnormality as deviation from social norms is that probably the majority of behaviour that deviates from social norms is unlikely to represent mental illness. Eccentric behaviours, for example the case of John Slater (Weekes & James, 1995) who lived in a cave that was often flooded by seawater because the open space helped him think more clearly, are not necessarily abnormal to the extent that health is harmed.
Evaluate; deviation from social norms
Easy definition to apply/use to measure abnormality; based on universally recognised principles of what is considered socially acceptable/not, clear where the boundaries of abnormality lie.
People with diagnosed psychopathologies; often deviate from social norms in their behaviour, support to this definition of abnormality.
Social norms change; what is accepted as socially abnormal change from one time period to another. Definition unreliable; suggests only relevant in a specific time period, not universally.
Ethnocentric bias in diagnosis; Social norms are culturally specific. Determine what is socially normal using the western classification systems suggests biased towards western cultural norms.
Although most social norms are universally recognised and agreed, some may be subject to interpretation and so this can lead to unreliable definitions as opinions can vary.
Problem with cultural relativism; social norms culturally specific. To judge what is considered abnormal on basis of social norms will vary from one culture to another. Not all moral principles can be universally applied.