Abnormality definition - Failure to function adequately

I cant write them all as a full point as I can't really remember them but hopefully it still helps a bit

- One limitation of failure to function adequately is that it can be criticized for not differentiating sufficiently between abnormal behavior and behavior which may be simply unconventional.

- Another limitation is that the individual may not be psychologically abnormal yet is categorized as so, for example, an immigrant who is learning English may not be able to communicate well therefore be classed as abnormal even though they are not.

- A third limitation is that it is difficult assess abnormality using failure to function adequately as some psychological disorders may not prevent a person from functioning adequately for example those with Bulimia.

These all suggest that failure to function adequatley is not an appropriate way of defining abnormality.