Moral justifications work, when they do, by invoking values that are shared in the common ground of the interlocutors. We asked 3- and 5-year-old peer dyads (N = 144) to identify and punish norm transgressors. In the moral condition, the transgressor violated a moral norm (e.g., by stealing); in the social rules condition, she/he violated a…

This study investigates how children negotiate social norms with peers. In Study 1, 48 pairs of 3- and 5-year-olds (N = 96) and in Study 2, 48 pairs of 5- and 7-year-olds (N = 96) were presented with sorting tasks with conflicting instructions (one child by color, the other by shape) or identical instructions. Three-year-olds differed from older…

In 2 studies, we investigated how peers establish a "referential pact" to call something, for example, a "cushion" versus a "pillow" (both equally felicitous). In Study 1, pairs of 4-and 6-year-old German-speaking peers established a referential pact for an artifact, for example, a "woman's shoe," in a…

Human children 18-24 months of age and 3 young chimpanzees interacted in 4 cooperative activities with a human adult partner. The human children successfully participated in cooperative problem-solving activities and social games, whereas the chimpanzees were uninterested in the social games. As an experimental manipulation, in each task the adult…