Jean Piaget studied children's notions of morality. Lawrence Kohlberg built on Piaget's research in devising his theory of stages of moral development in children. Agencies of socialization are the groups of people, along with the interactions that occur within those groups, that influence a person's social development. Within these agencies one finds a great deal of anticipatory socialization , in which the individual plays a role that he or she is likely to assume later in life. The family is the primary agency of socialization.
Schools are also very important agencies of socialization.
Conflicts sometimes arise between parents and school personnel over what should be taught in the schools. Scout, troops, churches, social agencies and leagues of all kinds are among the agencies of socialization found in most communities. When children's peer groups are faced with conflict and social change, they often organize themselves into gangs. The most controversial agency of socialization in the U. S. is mass media. The effect of television viewing on children and adolescents is the subject of intensive research.