In a Study by Fernald (1993), 5-Month-Old Children of English-Speaking

In a study by Fernald (1993), 5-month-old children of English-speaking parents were presented with approval and prohibition vocalizations in infant-directed (ID) and adult-directed (AD) English, and in ID speech in nonsense English and unfamiliar languages. Infants showed small but significant differences in facial affect in response to ID vocalizations in every language. Infants smiled more to approvals, and when they showed negative affect, it was more likely to occur in response to prohibitions. Infants did not show differential affect in response to approvals and prohibitions in AD speech. Discuss the implications of these results for our understanding of language processing in infancy.