“We think children are born with a skeleton of general expectations about fairness,” explains Sloane, “and these principles and concepts get shaped in different ways depending on the culture and the environment they’re brought up in.” Some cultures value sharing more than others, but the ideas that resources should be equally distributed and rewards allocated according to effort are innate and universal.
Other survival instincts can intervene. Self-interest is one, as is loyalty to the in-group — your family, your tribe, your team. It’s much harder to abide by that abstract sense of fairness when you want all the cookies — or your team is hungry. That’s why children need reminders to share and practice in the discipline of doing the right thing in spite of their desires.