Normal and abnormal personality development can be quantified in terms of 15 specific stepsin the self-organization of character as a complex adaptive system. Character is measured asthree dimensions of Self-directedness, Cooperativeness, and Self-transcendence, each with fivecomponents corresponding to steps in personality development. Each of these steps isdifferentially influenced by heritable temperament dimensions, antecedent steps in characterdevelopment, and life experiences. Predictions about the nonlinear dynamics of personalitydevelopment, such as equifinality and multifinality, are confirmed in longitudinal data aboutindividuals representative of the general population. The stepwise development of characterdetermines large differences between individuals in their risk of psychopathology, as well asvarying degrees of maturity and health.