The emergence, socialization, and growth of morality are of major importance in the social and behavioral sciences. Psychological theories have conceptualized the processes and origins of moral development in three major ways. First, theorists posit biology as the source of moral development, the natural emergence of an empathic predisposition. Second, they locate morality's source in society, the socialization or internalization of a society's prescriptive norms and values. Third, they feature mental coordination of perspectives as the primary source, the construction of mature moral judgment. Integrative theories or comprehensive views of moral development and prosocial behavior have appeared in the early twenty-first century.