Sigmund Freud's Theory of Psychosexual Development (1905)Freud's theory of development was based on the assumption that development is influenced by sexual drives. Freud proposed his theory of psychosexual development in his article "Three Essays on the Theory of Sexuality", originally published in 1905 and later translated into English in 1962. He theorized that from birth, humans have an energy instinctive sexual instinct (i.e. libido) which is an important element of personality development. Freud's theory of psychosexual development consists of five linear stages that span the lifespan. Each of these stages is characterized by a specific erogenous zone which is at the heart of the conflict during the developmental stage (Freud, 1962). Freud (1962) believed that the erogenous zones involved in development were the mouth, anus, and genital area. Conflicts and behaviors at each of the psychosexual stages are closely associated with these erogenous zones. As Freud's theory of development is linear, a child is unable to progress to the next stage – that is, unable to focus on the sexual energy associated with the primary erogenous content of the next stage (Freud , 1962). The conflict at the heart of the psychosexual stage must be resolved in order for an individual to move on to the next stage. According to Freud (1962), the success of each of these stages involves an expenditure of sexual energy. Freud (1962) hypothesized that the more energy used to overcome the conflict of a psychosexual stage leads to characteristics/traits/behaviors of that stage that persist into adulthood. He believed that all enduring characteristics/traits/behaviors are what can underlie personality and psychopathology in adulthood (Freud, 1962)........ middle of article...... enerativity versus stagnation, occurs in mid-adulthood. According to Erikson (1950), individuals at this stage develop a feeling of being part of society. Individuals who are able to contribute to society can develop a sense of generativity (i.e., a feeling of productivity and accomplishment). In contrast, Erikson (1950) believed that individuals who do not want to contribute to society may develop a feeling of stagnation. The eighth and final stage, integrity versus despair, occurs in late adulthood. According to Erikson (1950), the main task of this stage is retrospection. Individuals contemplate their achievements. If individuals believe they have had a successful life, they develop a sense of integrity. Individuals may be more likely to develop feelings of hopelessness if their lives are full of disappointments and unfulfilled goals (Erikson)., 1950).