Adler's psychology differs from the Freudian standpoint, which bases a person's psychology on sex and libido. Instead, Adler's psychology focuses on the individual's evaluation of the world with special attention to societal factors. According to Adler, a person must confront three forces: the societal, the love-related, and the vocational.These confrontations shape the final nature of a personality. Adler based his theories on a person's pre-adulthood development, emphasizing factors such as unwanted children, physical deformities at birth, and birth order.