A Multilab Study of Bilingual Infants: Exploring the Preference for Infant-Directed Speech

Abstract

From the earliest months of life, infants prefer listening to and learn better from infant-directed speech (IDS) compared with adult-directed speech (ADS). Yet IDS differs within communities, across languages, and across cultures, both in form and in prevalence. This large-scale, multisite study used the diversity of bilingual infant experiences to explore the impact of different types of linguistic experience on infants’ IDS preference. As part of the multilab ManyBabies 1 project, we compared preference for North American English (NAE) IDS in lab-matched samples of 333 bilingual and 384 monolingual infants tested in 17 labs in seven countries. The tested infants were in two age groups: 6 to 9 months and 12 to 15 months. We found that bilingual and monolingual infants both preferred IDS to ADS, and the two groups did not differ in terms of the overall magnitude of this preference. However, among bilingual infants who were acquiring NAE as a native language, greater exposure to NAE was associated with a stronger IDS preference. These findings extend the previous finding from ManyBabies 1 that monolinguals learning NAE as a native language showed a stronger IDS preference than infants unexposed to NAE. Together, our findings indicate that IDS preference likely makes similar contributions to monolingual and bilingual development, and that infants are exquisitely sensitive to the nature and frequency of different types of language input in their early environments.

Online measures of looking and learning in infancy

“…Our field is poised to embrace ambitious endeavors at scales that were unthinkable in the earlier decades of cognitive development research. Multi-lab replication efforts like ManyBabies (Byers-Heinlein et al, 2020;Byers-Heinlein et al, 2021), other types of large-scale collaborative networks (Sheskin et al, 2020), and online testing like that pioneered by LookIt and extended in the present work all have the potential to broaden the scope and impact of research on the developing mind. We hope our work can contribute to that effort.…”

Acoustic regularities in infant-directed speech and song across cultures

“…Some evidence suggests that infant-directed speech is primarily characterized by higher and more variable pitch 63 and more exaggerated and variable vowels 23,64,65 , based on studies in modern industrialized societies 23,28,49,50,52,66,67 and a few small-scale societies 51,68 . Infants are themselves sensitive to these features, preferring them, even if spoken in unfamiliar languages [69][70][71] . But these acoustic features are less exaggerated or reportedly absent in some cultures 60,66,72 and may vary in relation to the age and sex of the infant 66,73,74 , weighing against claims of cross-cultural regularities.…”

Habla conmigo, daddy! Fathers’ language input in North American bilingual Latinx families

“…In agreement with the research in monolingual settings, the quality of language input and early interactions also affects bilingual Latinx infants’ language development. Empirical research has highlighted a particular characteristic of language input in infancy: From the first months of life, bilingual and monolingual infants demonstrate a robust preference for parentese over adult‐directed speech (Byers‐Heinlein et al, 2021; Cooper & Aslin, 1990; Fernald, 1985; The ManyBabies Consortium, 2020). Parentese is a speaking style recognized by its exaggerated social affect and positive emotion (Kim & Johnson, 2014; Singh et al, 2002), simpler phonology and grammar, fewer and simpler lexical items, a higher pitch, and exaggerated intonation contours (Fernald, 1985; Fernald et al, 1989).…”