GAIN-LOSS THEORY. See INTERPERSONAL ATTRACTION THEORIES.
GALEN’S DOCTRINE OF THE FOUR TEMPERAMENTS. The ancient Greek physician/philosopher Claudius Galen (c. A.D. 130–200) formulated the doctrine of the four temperaments of personality based on the earlier doctrine of bodily humors as outlined by the Greek philosopher Empedocles (c. 495–435 B.C.) and the Greek physician Hippocrates (c. 460–377 B.C.). Empedocles posited that the universe was made up of the four basic elements of earth, fire, air, and water where combinations of these four elements, in one way or another, could explain all known substances. Each of the four elements had corresponding ‘‘qualities’’: earth—cold/dry; fire—warm/dry; air—warm/moist; and water—cold/moist. When the qualities were taken with respect to the human body, they assumed the form of four substances or humors: blood, yellow bile, black bile, and phlegm. Hippocrates considered these humors to be the basic constituents of the body where—depending on their deficiency, excess, or balance—they could cause both disease and health. In this sense, Hippocrates’ naturalistic approach and explanations of cause–effect relationships anticipated modern medicine and psychology, rather than appealing to the presence of ‘‘evil spirits’’ as the cause of diseases. Later, Galen systematized the relationship of the Empedoclean/Hippocratic notions of elements/humors into a general personality theory of temperaments where an excess of blood characterized the sanguine (warmhearted, cheerful) person, a preponderance of black bile related to the melancholic (sad, fearful) personality, an excess of yellow bile led to the choleric (fiery, highly reactive) person, and an excess of phlegm typified the phlegmatic (slow) individual. Galen’s doctrine of the four humors and their corresponding temperaments was viable until about A.D. 1400, when the Renaissance and the rebirth of medicine took place, and the doctrine faded. While Galen’s doctrine is now chiefly of historical interest only, certain vestiges of