Sigmund Freud, known as the father of psychology, developed some of the first theories of modern psychology. One of his best-known theories is the structural model of the psyche. According to Freud, most of what motivates humans is buried in the unconscious. There are three main forces that drive humans: the id, the ego and the superego. The id is the sum of basic personal needs and desires. He is completely selfish and doesn't care about sensitivity or reality. He strives to get what he wants, when he wants it without any other consideration and is primarily concerned with sex. The second part of the personality is the ego. The ego is the realization of reality. It is the job of the ego to, in a sense, counteract selfishness and, impractically, the id. The third part, the superego, is made up of morals and acquired beliefs about good and evil. According to Freud, to have a healthy personality, the ego must be dominant. The id must be satisfied but taking care not to disturb the superego. In some cases however, there is an imbalance in either the id or the superego, causing an imbalance between the id and superego....