Maturation: a genetically determined process of growth that unfolds naturally over a period of time. Structural-organismic perspective: theoretical approaches that describe psychological structures and processed that undergo qualitative or stage-like changes over the course of development. Psychodynamic theory: freud"s theory that development, which proceeds in discrete stages, is determined largely by biological based describes shaped by encounters with the environment and through the interaction of three components of personality; id, ego, superego. Id: the person"s instinctual drives; the first component of the personality to evolve, operates on the basis of pleasure principle. Ego: the rational, controlling component of the personality, which tries to satisy needs through appropriate, socially acceptable behaviours. Superego: the personality component that is the repository of the child"s internalization of parental or societal values, morals, and roles. Psychosocial theory: eriksons"s theory of development that sees children developing through a series of stages largely through accomplishing tasks that involves them in interaction with their social environment.