 Note that this kind of "rationality" does not say that the individual's actual goals are "rational" in some larger ethical, social, or human sense, only that he tries to attain them at minimal cost.Only naïve applications of the "homo economicus" model assume that this hypothetical individual knows what is best for his long-term physical and mental health and can be relied upon to always make the right decision for himself.See rational choice theory and rational expectations for further discussion; the article on rationality widens the discussion.