This document provides an overview of personality theories taught in a psychology course. It defines personality as an individual's pattern of character, behavioral, temperamental, and emotional traits. Personality encompasses both unique individual traits as well as common traits shared across people. Personality characteristics can remain consistent over time or vary by situation, and may evolve throughout one's life. Personality theories are useful for predicting behavior, understanding behavior, and facilitating behavior change, but they also narrow our focus and limit perspective. The document recommends knowing multiple theories to gain a broader understanding of personality, including psychoanalytic, trait, biological, behavioral, humanistic, and cognitive approaches.