Do you remember Kohlberg's Stages of Moral Development? 1. Preconventional- This is that lil' kid who follows all the rules stated to him by authority figures. The age for this stage typically is up to the age of 9. They act morally but only out of their own self-interest and to simply avoid getting in trouble or to get something out of it. 2. Conventional- An example of reasoning in this stage is one who refuses to steal bread for a starving family because it is against the law. This stage lasts from around 10-14 and focuses on not getting in trouble as well as being approved of. 3. Postconventional- High Schoolers up to adulthood fall into this stage. Becoming a vegan is one example. To some, not eating meat or animal products is personally ethical and helps reduce harm to living animals. To see a full review check the wikipedia link.