I am not sure whether the four temperaments theory has been proven wrong....I just think it has been replaced based on the scientific approach to all sciences in general, one of which is medicine. Hyppocrates was the "founder" of Greek Medicine and of what St Isidore of Seville says in his Etymologies the founder of rational medicine, and not the inventor of medical practices based solely on experience, observation and encantations. Some modern research has claimed that the theory of the four temperaments is based on true science as well. I looked at the wikipedia source and I found the practice was replaced, not proven wrong. I am sure they were excess steming from it. http://www.answers.com/topic/temperament