Examines whether three-month-old infants can detect variations within the single expression category of smiling and whether individual differences in infants' sensitivities are related to identifiable mother or infant behaviors. (HOD)

Examines the implications of temporal separation for children's developmental differences in inferences drawn about an individual's characteristics after observing multiple instances of that individual's behavior. Also tests two competing hypotheses about how young children process information separated in time. (HOD)