Views of abnormality change across cultures, vary within cultures over time, and vary from group to group (e.g. Chavs and Goths) within the same society (cultural relativism)
The cut off points for statistical infrequency are rather arbitrary, it ignores desirability of behaviour, and it doesn't account for 'abnormal' behaviours that are as frequent as 'normal' behaviours
Some disorders, for example depression, are statistically very frequent, but still classified as abnormal. Furthermore, having an IQ over 150 is not frequent yet it doesn't mean it is not desirable
Behaviour that deviates (moves away) from these norms is considered abnormal
Social norms are approved and expected ways of behaving in a particular society or social situation, they can be explicit (e.g. laws) or implicit (e.g. unwritten rules)
Different cultures have different social norms and expectations of behaviour, for example, Cochrane (1977) found that black people were more often diagnosed with schizophrenia than white or Asian people, but this was not found in Jamaica
It differentiates between desirable and undesirable behaviour, unlike statistical infrequency which suggests rare behaviour is abnormal even if desirable
A weakness of the deviation from social norms definition it allows mental health professionals to abuse their power by classifying people as mentally ill just because they 'break the rules' in society.e.g. 1950s having communist views in America was classed as abnormal - ppl sent to mental health institutions. Can be a way of controlling non-conformists
A strength of deviation from social norms definition is that is has practicalapplications in identifying developmental norms e.g. Using a nappy at 2 is considered normal perhaps not at 30. In turn allowing support to be put in place
The individual sees the world around them in a way that is similar to how others see the world, focused on the distortions of thinking that some people may experience
For ideal mental health to be achieved the individual should experience all of these criteria and if some are not fulfilled the person will experience difficulties