The origins of infants' fairness concerns and links to prosocial behavior.

Concerns about fairness are central to mature moral judgments. We review research regarding the origins of a sensitivity to distributive fairness, and how it relates to early sharing. Infants' sensitivity to fairness appears to be commensurate with that of school-age children: infants notice violations to fairness norms and evaluate individuals based on their fair or unfair behavior. However, it may differ in other ways: there is no evidence that infants punish unfair individuals. Sharing behavior plays a role in both the developmental emergence of, and subsequent individual differences in, infants' fairness concerns. These results motivate novel questions, such whether infants can entertain other models of fairness, whether infants' socio-moral concerns hang together, and the relationship early fairness sensitivities and later fair behavior.