Human social interaction depends on individuals identifying the common ground they have with others, based both on personally shared experiences and on cultural common ground that all members of the group share. We introduced 3- and 5-year-old children to a culturally well-known object and a novel object. An experimenter then entered and asked,…

To better understand the form and recognizability of neonatal smiling, 32 newborns (14 girls; M = 25.6 hr) were videorecorded in the behavioral states of alertness, drowsiness, active sleep, and quiet sleep. Baby Facial Action Coding System coding of both lip corner raising (simple or non-Duchenne) and lip corner raising with cheek raising…