Final answer:
Freud made unique contributions to psychology with his theory of psychoanalysis, which focused on the unconscious mind and the development of personality. One of Freud's basic assumptions was that early childhood experiences shape our mental life. He also proposed the existence of the id, ego, and superego as components of personality.
Step-by-step explanation:
Sigmund Freud made several unique contributions to the science of psychology with his theory of psychoanalysis. One of the basic assumptions in Freud's theory is that a large part of our mental life is influenced by early childhood experiences and takes place outside of our conscious awareness. Freud also proposed the existence of three components of personality: the id, ego, and superego. These components interact to shape our thoughts, behaviors, and conflicts.