The present research explored whether infants and toddlers would have early expectations of socio-moral norms. In particular, we asked whether and how children’s expectations about reciprocity would be modulated by considerations of ingroup loyalty. Chapter 2 focused on the idea of “escalation” and provided evidence that infants expect an individual to retaliate more severely against an outgroup member than against an ingroup member. Chapter 3 focused on the idea of “co-retaliation” and suggested that both infants and toddlers expect an individual to retaliate against an outgroup member who had previously hindered the individual’s group member. Chapter 4 focused on the idea of “privilege” and showed that toddlers expect an individual to act more positively in response to a friendly overture by an ingroup member than by an outgroup member.Experiments described in this dissertation provide converging evidence that infants and toddlers have rudimentary socio-moral expectations about actions and interactions within social contexts; they are sensitive to various markers of social groups; and their expectations of reciprocity are modulated by considerations of ingroup loyalty. These socio-moral expectations emerge early in life and are likely to be based on a small set of innate socio-moral principles.