The five-factor model is based on the work of Carl Rogers and the five traits he identified (unconditional positive regard, empathy, congruency, etc.).

Five-Factor Model

A model that describes human personality as composed of five broad dimensions: openness, conscientiousness, extraversion, agreeableness, and neuroticism.

Carl Rogers

An influential American psychologist who founded client-centered therapy, emphasizing the importance of the personal growth and self-direction of the client.