Sigmund Freud's psychoanalytic theory proposed that personality is shaped by unconscious motives and childhood experiences. He structured the personality into three parts: the id (operates on the pleasure principle), the ego (operates on the reality principle), and the superego (represents internalized ideals and provides standards for judgment).

In contrast to Freud's determinism, humanistic theorists like Abraham Maslow and Carl Rogers focused on the potential for healthy personal growth. Maslow proposed a hierarchy of needs, culminating in self-actualization—the motivation to fulfill one's potential. Rogers believed that growth is promoted by an environment of genuineness, acceptance (unconditional positive regard), and empathy.