The term atrabilious defines an individual's predisposition to be sad, despondent, and negative. An atrabilious person has a melancholic temperament. With the evolution of medicine, and particularly of psychology, the temperament of people is no longer perceived as fixed from birth
, but rather formed and evolved according to family, social, environmental, and sometimes medical influences. The influence of the bile
on the melancholic character of an individual has been discarded as an explanation.