AO3 statistical infrequency and deviation for social norms

• Statistical and frequency


  Useful in clinical practice both as part of a formal diagnosis and to assess the severity of an individual's symptoms
• Diagnosis of intellectual disability disorder

  • Requires an IQ of 70, which is below 2%
• Depression inventory


  • A score of 30+ is widely interpreted as severe depression
• The value of statistical and frequency criterion is useful in diagnostic and assessment process
• Statistical and frequency characteristics can be positive as well as negative
• Not everyone with an IQ below 70 is abnormal, and not everyone with an IQ above 130 is abnormal
• Statistical and frequency can form part of assessment and diagnostic procedures, but it's never sufficient as a sole basis for defining abnormality
• Deviation from social norms


  Its usefulness in clinical practice
• Antisocial personality disorder


  • Key defining characteristic is the failure to conform to culturally acceptable ethical behaviour (e.g. recklessness, aggression, violating the rights of others, deceitfulness)
• Schizotypal personality disorder


  • The term 'strange' is used to characterise the thinking, behaviour and appearance of people with the disorder
• The deviation from social norms criterion has value in psychiatry
• Variability between social norms in different cultures and even different situations is a limitation of the deviation from social norms criterion
• A person from one cultural group may label someone from another group as abnormal using their standards rather than the person's standards
• Hearing voices


  • Norm in some cultures (as messages from ancestors), but seen as a sign of abnormality in most parts of the UK
• Even within one cultural context, social norms differ from one situation to another (e.g. aggressive and deceitful behaviour is more socially unacceptable in the context of family life than in the context of corporate deal-making)
• It is difficult to judge deviation from social norms across different situations and cultures