Describe the universality of infant-directed speech.

Infant-directed speech has been documented in many languages and cultures. Comparisons of mothers from Fiji, Kenya, and the United States show the use of high-pitched speech, which is characteristic of infant-directed speech, with infants. The pattern of infant-directed speech is similar across cultures such that adults can discriminate it from adult-directed speech even while listening to a language they do not speak. For example, when adults in the Turkana region of northwestern Kenya listened to speech produced in English by American mothers, they were able to discriminate between infant-directed and adult-directed speech, suggesting that infant-directed speech is recognizable to adults of many cultures. Despite this, adults of different cultures vary in their interactions with infants.
Although parents from different cultures vary in how often they respond to their infants, parental response patterns that are warm, consistent, and contingent on infant actions are associated with positive language development in infants across cultures. For example, in a study of six cultural communities, mothers from Berlin and Los Angeles were more likely to respond to infant nondistress vocalizations and gazes than were mothers from Beijing and Delhi, as well as Nso mothers from various cities in Cameroon (Kärtner et al., 2008). In contrast, Nso mothers responded more often to infant touch than did mothers from other cultures. Although parental responsiveness may look different and take different forms across cultures, its benefits generalize across families from varying cultural communities and socioeconomic strata