Reviews research on quantitative and qualitative indexes of play, and relationships between play and language. Finds consistent relationships between duration and level of play throughout early development, and parallel developments in play and language. Indicates that measures of spontaneous activity and habituation in infancy predict…

Examined whether 6-month-olds expect people to behave differently toward persons and inanimate objects. Found that infants habituated to an actor talking to something hidden behind an occluder looked longer at an object, whereas infants habituated to an actor reaching and swiping looked longer at a person. No difference in looking at stimuli was…

This editorial proposes that the dependent variables that predict childhood intelligence quotient (IQ) from habituation and recognition memory assessments made during infancy may primarily reflect individual differences in rate of information processing. Inhibition may be a stable thread in mental development. (Author/SLD)

This review of literature on infant habituation and recognition memory performance as predictors of later IQ concludes that the level of prediction is (1) substantial; (2) higher for at-risk than nonrisk children; and (3) not higher than the level of predictions based on parental education and socioeconomic status. (MDM)