Statistical Infrequency shows which characteristics/behaviours are abnormal by using normal distribution to see how far above or below te average someone is
Deviation from ideal mental health identifies people who do not have ideal mental health
Jahoda's ideal mental health includes: no symptoms of distress, can cope with stress, independence & self-esteem, self-actualisation, successful in work, love, & leisure
Failure to function adequately is an inability to maintain basic standards of living, nutrition & hygeine e.g showering, maintaining relationships, holding a job
Deviation from social norms is when people do not behave in the way they are expected to by society