The humours each had associated physical and mental characteristics; the result was a system that was quite subtle in its capacity for describing types of personality.

Humour Qualities Element Personality
Sanguine hot, moist air Optimistic, red-cheeked, corpulent, irresponsible (compare Falstaff).
Choleric hot, dry fire Short-tempered, red-haired, thin, ambitious (compare Hotspur).
Phlegmatic cold, moist water Sluggish, pallid, corpulent, lazy (Are any of Shakespeare's characters phlegmatic?).
Melancholic cold, dry earth Introspective, sallow, thin (compare Richard II, Hamlet).

In addition, different humours could be combined for more complex personality types: choleric-sanguine, phlegmatic-melancholic, and so on.