Kowalski and Westen, (2011) "moral development refers to the acquisition of values and rules for balancing the potentially conflicting interests of the self and others" (p. 530). In the social learning theory, one develops morality through learning what behaviors are acceptable from the external environment. In the psychoanalytic theory, one develops morality through one's conflict between instinctual drives and society's demands. In cognitive development theories, morality grows out of reasoning or cognition. Personality theories take into account the factors that contribute to one's development. Moral development in adolescence is influenced one's parent or caregiver. As one develops morals and ethics are established to govern one's own life, and further develops morals and ethics as one establishes identity. I do not believe that moral development changes for everyone. Moral development may not change for those who suffer from reactive attachment disorder. One who suffers from reactive attachment disorder lacks conscience and empathy toward others. Moral development can be hindered if one is exposed to abuse and neglect in early childhood. Others who lack mental capacity can fail to develop basic moral values. Mental capacity may be lacking because of certain psychological disorders.
Kowalski, R., & Westen, D. (2011). Psychology (6th ed.). Hoboken, NJ: Wiley.