Human beings share many cognitive skills with their nearest primate relatives, especially those for dealing with the physical world of objects (and categories and quantities of objects) in space and their causal interrelations. But humans are in addition biologically adapted for cultural life in ways that other primates are not. Specifically, humans have evolved unique motivations and cognitive skills for understanding other persons as cooperative agents with whom one can share emotions, experience, and collaborative actions (shared intentionality). These motivations and skills first emerge in human ontogeny at around one year of age, as infants begin to participate with other persons in various kinds of collaborative and joint attentional activities. Participation in such activities leads humans to construct during ontogeny perspectival and dialogical cognitive representations.