Psychoanalysis is a psychological theory developed by Sigmund Freud in the late 19th/early 20th century. It views the mind as comprising the id, ego, and superego, and proposes that early childhood experiences, especially relating to sexuality and pleasure, shape adult personality. Psychoanalytic techniques aim to bring unconscious thoughts and desires into awareness in order to gain insight. However, Freud's theories have been criticized for lacking scientific rigor and for overemphasizing sexuality.