The oldest and st method, then, of describing differences in personality was to (36)_________ people according to (37)_________. Such a system is called a Typology. A famous example of this method was (38)_________forth in Greece about the year 400B.C. A (39)_________ named Hippocrates theorized that there were four (40)_________, or humors, in the body: blood, yellow bile(胆汁), black bile, and phlegm (粘液). (41)_________to each humor, there (42)_________a definite type of personality. A person in whom all four humors were in perfect balance had a (43)_________personality. (44) ______________________________. Someone with too much yellow bile was irritable and easily angered. (45) ______________________________. An oversupply of phlegm caused a human being to be slow and unfeeling. (46)______________________________. Today, however, personality theories and classifications may also include factors such as heredity, the environment, intelce, and emotional needs.