There are two popular psychological theories regarding moral development. These are brought forth by psychologists Jean Piaget and Lawrence Kohlberg.
Jean Piaget¹
Stage 1: Moral Realism
Characterized by egocentrism and blind adherence to rules. Children in this stage do not consider whether an act is right or wrong but only whether it is likely to have a good or consequence for them personally.
Stage 2: Morality of Operation
Rules become more flexible. The child is more sympathetic and understands that many rules are social conventions that may be altered by mutual consent. This stage is reached at the age of 10 years or older.
This stage develops throughout their life. As children grow, they begin to understand the reciprocal benefit of moral decision-making. This leads to the discovery of ideal reciprocity, wherein adolescents recognize a type of fairness beyond simple reciprocity that includes a consideration of other people’s best interests.
Lawrence Kohlberg¹
Preconventional Level - Morality is externally defined.
Stage 1: Morality of punishment and obedience
Children blindly obey authority and avoid punishment.
Stage 2: Morality of naive instrumental hedonism
Children make moral choices egocentrically, guided by pleasantness or unpleasantness of the consequences of behaviour.
Conventional Level - An understanding that the social system has an interest in people’s behaviour.
Stage 3: Morality of maintaining good relations
Children want to be regarded by people who know them as good and well behaved. Moral decisions are based on perceived social pressure.
Stage 4: Morality of maintaining social order
Laws and morals and rules are perceived as instruments to maintain social order and as such, must be obeyed.
Postconventional Level - People realize that moral rules have some underlying principles that apply to all situations and societies.
Stage 5: Morality of social contract
People recognize that rules are social contracts, that not all authority figures are infallible, and that individual rights can sometimes takes precedence over laws.
Stage 6: Morality of universal ethical principles
People perceive rules and laws as being justified by abstract ethical values, such as the value of human life and the value of dignity.
Stage 7: Morality of cosmic orientation
People adopt values that transcend societal norms as they grapple with issues such as “Why be moral at all?” This stage represents the peak of moral development and Kohlberg notes that very few people reach Stage 7.
Reference:
1. Carlson, Neil R., Buskist, W., Heth, C.D, Schmaltz, R. Psychology - The Science of Behaviour.