This chapter begins with humans' nearest primate relatives to see whether and to what degree they engage in morally-relevant social behaviour. It then focuses on young children of different ages and how they move from the general primate mode of social interaction to a more specifically human mode of social, perhaps moral, interaction. The chapter explores whether the cooperative activities of chimpanzees and children are structured by anything like a joint commitment. Chimpanzees and infants show morally-relevant behaviours like helping and sharing and even expect their conspecifics to treat them with sympathy. Sympathy-based prosociality is expressed both in intentions and expectations, obligations based on joint commitments create not only intentions, but also specific expectations. The chapter reviews the evidence for chimpanzees' and children's enforcement of social norms. The most convincing evidence for young children's burgeoning collective and agent-neutral morality is their behaviour in third-party situations in which they are not directly affected.