"Social brain" changes structure with evolving concept of fairness

An important aspect of social interactions and cooperation is “fairness,” which is determined by perceptions of others’ intentions and preferences for “egalitarianism” or equal outcomes. Others’ intentions have a considerable influence on our ultimate decisions, because we tend to reciprocate intention rather than outcome. Interestingly, this relative importance is determined by age. Younger children usually prefer egalitarian outcomes, whereas older children and adolescents consider reciprocity and intention.