Human development describes an individual's progression through life in a series of stages. Humans move through developmental stages individually depending on both genetics and environment. The evaluation and investigation of developmental stages began as early as 335 to 323 B.C. when Aristotle proposed a three-stage model. Sigmund Freud and Erik Erikson created developmental theories during the 21st Century.
Sigmund Freud, known as the father of psychoanalysis, focused his research around sexual themes. During Freud's college years, hysteria in women claimed the interest of physicians. In later years, physicians discovered the women were actually suffering from sexual frustration. These theories influenced Freud which led to the writing of "Three Essays on Sexuality." The publication outlined five psychosexual stages of development humans progressively move through during the lifespan. The oral stage occurs from birth to 1 year. The infant seeks pleasure through the mouth by sucking, swallowing, biting and gumming. The anal stage affects toddlers between the ages of 1 to 3 years. Children toilet train at this age and discover the feelings associated with this ability. Children aged 3 to 6 years old encounters the phallic stage. The child begins to focus on the genitals through the libido and identify with the same-sex parent or guardian. The latent period appears between 7 and 11 years and refers to a latency period of the libido. Children focus on activities such as friends, school and activities. Freud believed that from adolescence through adulthood, the genital period existed. This period revolved around the goal of romantic relationships.
Erik Erikson developed an eight-stage developmental theory after Freud's death. Erikson favored the work of Freud but disagreed with his theories on sexuality driving an individual's personality. The first stage, trust versus mistrust, appeared between birth and 1 year old. A child between the age of 1 and 3 years developed autonomy versus doubt. A child in this stage begins controlling eating, toileting or talking. Initiate versus guilt emerges between 3 and 6 years old. The child learns to control the environment better. The child between between ages 7 and 11 years experiences industry versus inferiority. The child gains a sense of self-worth through a mastery of skills. During adolescence, the child works through identity versus role confusion. The adolescent adjusts to the intertwining roles such as a student, son or daughter, brother or sister or athlete. Erikson believed that adults moved through three different stages. The intimacy versus isolation stage initiates the ability to hold commitments with others. The generativity versus stagnation stage involves the decision of whether to participate in community integration, a family or career. The final stage labeled integrity versus despair involves reflecting on choices and actions throughout life.
Freud and Erikson's theories on stages of development contain similar themes for 1 to 3 years, 7 to 11 years and adulthood. During the 1 to 3 years old stage, both theories agree the child initiates control of specific actions. Freud and Erikson's stages of 7 to 11 years focuses on mastering new skills and activities. The adulthood stage in both theories demonstrates a focus on romantic relationships at some point.
The incorporation of sexual pleasure within Freud's stages of development creates a significant difference from Erikson's stages. Erikson's stages of development center around issues or tasks that are met at specific ages. Erikson's theory outlines that if an individual does not complete a stage successfully he moves on to the next stage carrying remnants of the older stage. Freud believed that if failure occurs during any stage, the individual becomes fixated. The fixation of a stage could later lead to personality disorders.