1) Freud's psychoanalytic theory views personality as formed by the interaction between the id, ego, and superego. The id seeks pleasure, the ego balances demands, and the superego acts as a moral conscience.
2) Trait theory sees personality as a combination of stable traits that are consistent over time and situations. The Big Five model identifies openness, conscientiousness, extraversion, agreeableness, and neuroticism.
3) Humanistic theory emphasizes people's inherent goodness and ability to improve. Rogers saw the self-concept as shaped by others and the ideal self, with unconditional positive regard enabling self-actualization.