Via statistical definition, any relatively usual behaviour /characteristic can be defined as normal and any behaviour that is unusual is abnormal i.e. Intellectual disability disorder & IQ scores
Deviation from social norms
When a person behaves in a way that is different from how we expect people to behave i.e. Homosexuality, antisocial personality disorder, crime
Failure to function adequately
When a person cannot cope with the demands of everyday life/ no longer conforms to standard interpersonal rules i.e. Can’t maintain basic standards of hygiene or relationships
Deviation from ideal mental health
Ideal mental health is what makes anyone normal and provides a checklist which we can assess ourselves and others i.e. When people have no symptoms of distress
(Regular people need a bit of stress as an incentive)