Statistical Infrequency is a definition of abnormality. According to this definition, a behaviour is seen as abnormal if it is statistically uncommon, or not seen very often in society.
Deviation from social norms
Straying away from societal norms accepted by the majority.
failure to function normally.
unable to complete daily tasks, hygiene, working or going to school. Failure to keep a job or a relationship.
Living conditions…
Deviation from ideal mental health.
Jahoda made a criteria of what you need to have in order to have the ”Ideal” mental health. She found all the things that were traits of a healthy mental health to dissect what a bad one would be.