Epigenetic theory is a principle expounded on by psychologist Erik Erikson that claims that personality develops in eight predetermined stages. This theory draws heavily upon some of Sigmund Freud's theories concerning the superego, ego and id.
Erikson's theory outlined eight stages of personality development, arguing that each stage depended on reaching a balance between concepts. The concepts for each stage were trust versus mistrust, autonomy versus shame or doubt, initiative versus guilt, industry versus inferiority, identity versus role confusion, intimacy versus isolation, generativity versus stagnation and integrity versus despair.
Erikson claimed that if a person does not develop fully within each state, he is fundamentally held back in life. For example, a baby learns to either trust or mistrust in infancy. If the infant does not pass this stage and successfully move on to autonomy versus shame as a toddler, this incomplete stage may effect his later development. Proponents of epigenetic theory believe that if a person successfully completes these stages at the correct times from infancy to adulthood, that person can reach a state of self-actualization. Erikson also outlined a system of zones, modes and modalities within epigenetic theory to show at what times a person should pass through each stage.