Ancient Greeks and Romans categorized four temperaments based on types of fluids in the body: sanguine (cheerful, optimistic, vain, unpredictable), phlegmatic (cool, persevering, needing direction), melancholic (soft-hearted, does things for others, slow to respond), and choleric (stubborn, domineering, opinionated, self-confident). How different or similar are these typologies from modern personality theories?