Briefly describe and critique the principles used to establish the criteria for abnormality. Which definition best defines the concept of abnormality?

Several principles are commonly used when determining the definition of abnormality. The statistical concept claims that behaviour should be judged abnormal if it occurs infrequently in the population. However, not all infrequent thoughts or actions should be considered abnormal. For example, those with an extremely high IQ are rare, but would be considered gifted as opposed to "abnormal." As well, some problem behaviours are quite common (e.g., depression, problematic alcohol use, cannabis use). Personal distress and dysfunction are often used as criteria. Patients experiencing a manic episode may feel little distress, however, and individuals who feel dissatisfied or in despair would not be labelled abnormal. Violation of social norms is also a criterion by which some people judge the presence of abnormal behaviour. People with schizophrenia, for example, may behave in ways counter to social norms; yet, so do criminals, and not all criminals are diagnosed with a mental disorder. It is generally a mental health expert who determines whether an individual suffers from a disorder; yet some believe that mental illness is socially constructed and is judged differently by different persons. None of the above criteria, on its own, is satisfactory in defining abnormal behaviour. No single criterion must be present or sufficient in defining abnormal behaviour, and generally all are used to some degree.