The Greek Humors

Personality Types trace their origins all the way back to the Greek Humors. The Humors were meant to provide a qualitative description, each representing a certain aspect of personality as a whole. Each Humor was also used to describe a type of person whose personality was primarily composed of that Humor.

The Personality of a Choleric individual is composed of all the Humors
with the Choleric Humor composing the greatest part.

Jung expanded on the Greek Humors in his Personality Types, and his system inspired the work of Isabel Briggs Myers and Katharine Cook Briggs. Many other modern personality systems borrow directly from this model.

Here's a great TEDx talk on Personality based on the Humors