The term 'abonormal' means deviating from the average. Therefore, if we were to adopt literal approach to defining abnormality, we would conclude that any rare behaviour or ability is abnormal. This, however, is not a useful way of defining abnormality as it doesn't take into account wether or not the behaviour is desirable.

Deviation from ideal metal health focuses on what is mormal as opposed to what is abnormal by deciding what abnormality is, anything that doesn't satisfy this criteria of 'normal' must be therefore be abnormality. Jahoda (1958) spoke about 'normality'. As being a positive state of mental heaath. According to Jahoda, several conditions in order to satisfy what she called optimal living.
The conditioms for optimal living are as follows; a positive view of self ( meaning the person must have a feeling of self- worth and a reasonable extent of self esteem) , autonomy ( the person must show a level of independence), actualisation ( the person must become the best they can), accurate view of reality, environmental adaptability and finally resistance to stress.

There are a few limitations of this approach to defining abnormality. First, self actualisation is theoretically ideal concept that very few people are actually able to achieve. In order to self actualise a person must reach the peak of their abilities, ambitions and desires in life, but the majority of people comfortably settle for a situation somewhat below self actualisation. Second, being resistant to stress and not suffering from it's consequences is an ideal state of memtal health, however stress can be actually be benificial in some circumstances. Many athletes, actors, public speakers etc. actually perform better under a degree of stress. Lastly, self actualisation is particularly relevant to thr Western culture. Non-western or collectivist cultures value the success of a community