Central to Pietraszewski's theory is a set of group-constitutive roles within four triadic primitives. Although some data from the developmental and biological sciences support Pietraszewski's theory, other data raise questions about whether similar behavioral expectations hold across various ecological conditions and interactions. We discuss the potential for a broader set of conceptual primitives that support reasoning about groups.

Spelke'sWhat babies knowdescribes the remarkably sophisticated mental lives of infants through the theoretical framework of core knowledge. To Spelke, young infants possess six independent core domains, two of which allow them to reason about the social world: the core agent and the core social being systems. Critically, Spelke argues that these core systems fail to communicate prior to 10 months, resulting in an inability to understand social goals. In this commentary, I review evidence that, contrary to Spelke's claims, young infants (...) show robust understanding of social goals and intentions, consistent with claims of an early emerging moral core. (shrink)