Founder of psychoanalysis Sigmund Freud created a psychosexual model of human development based upon the erogenous zones of the body. He believed that as these zones matured neurologically, they activated the emotional world of the child (largely resident in the unconscious), and in the course of doing so, created the basis for later emotional health or mental illness in adulthood. The stages are as follows:
- Oral Stage of Psychosexual Development (ages 0-18 months) – At this stage, the infant is focused upon getting pleasure from its mouth, especially through breastfeeding, which may be a source of satisfaction or frustration for the baby.
- Anal Stage of Psychosexual Development (18 months – 3 1/2 years) – At this stage, the young child is fixated upon its own process of eliminating feces, experiencing pleasure in the anal regions of the body, and reacting emotionally to attempts by parents or other caregivers to control this physical function through toilet training.
- Phallic Stage of Psychosexual Development (3 1/2 years – 6 years) – At this stage, the penis or vagina is the source of erotic satisfaction for the child, and he or she fantasizes about getting pelvic pleasure with the opposite sex parent and aggressively doing away with the same sex parent (the Oedipal Crisis).
- Latency Stage of Psychosexual Development (6 years – puberty) – At this stage, the emotional surges of the previous three stages go into hiding for a few years as the child learns how to repress, project, introject, sublimate, and in other ways channel the psychosexual energies of their earlier development.
- Genital Stage of Psychosexual Development (puberty – adulthood) – At this stage, the psychosexual instincts of the first three stages of development reassert themselves at puberty, but instead of being directed toward fantasy or the child’s own body, are directed outward toward a genuine love relationship focused on heterosexual genital sex.
For more information about the stages of life in different cultures and traditions, see Thomas Armstrong , The Human Odyssey: Navigating the 12 Stages of Life.