Does bilingualism affect the preference for infant-directed speech? Evidence from ManyBabies 1B

• In Event: 3-145 - ManyBabies: Bringing large-scale collaborative projects to infant development research

Integrative Statement

From the earliest months of life, infants prefer listening to infant-directed speech (IDS) over adult-directed speech (ADS; Dunst, et al., 2012). Yet, IDS differs across languages, individuals, and cultures, both in form and in prevalence. Further, the vast majority of research on infants’ IDS preferences has been conducted in North America, using English speech typically directed at North American, monolingual, English-hearing infants (Dunst et al., 2012).

Infants growing up bilingual provide a particularly useful wedge in understanding experiential influences on infants’ attention to IDS. Bilingual infants are exposed to IDS in two languages, in which the form, prevalence, and function of IDS may vary. This unique aspect of their experience can allow researchers to investigate how exposure to IDS in particular languages affects infants’ preferences for this relevant speech register.

Examining bilingual infants’ preference for IDS can also yield insights about the nature of bilingual development itself. Several lines of research suggest that early exposure to two or more languages changes some aspects of early development (Byers-Heinlein & Fennell, 2014): bilinguals maintain sensitivity to non-native consonant contrasts (García-Sierra et al., 2016; Petitto et al., 2012; Ramírez et al., 2017), tone contrasts (Graf-Estes & Hay, 2015; Liu & Kager, 2016a), and visual differences between languages (Sebastián-Gallés et al., 2012) until a later age than monolinguals. This raises the possibility that preference for IDS versus ADS could have a different developmental course for bilingual versus monolingual infants.

ManyBabies 1 Bilingual is a large-scale, multi-lab, pre-registered attempt to understand how bilingualism affects infants’ preference for IDS versus ADS. In all labs, we are using looking time measures to index infants’ preference for North American English IDS versus ADS. Because infants vary widely in their experience with North American IDS, our multi-site approach will give us precision in estimating the overall effect size of bilingual infants’ preference for IDS in comparison to monolingual infants, while also allowing us to disentangle how experience with specific languages moderates this preference. Our findings will build in preliminary findings from the ManyBabies Monolingual sample, indicating that preference for North American IDS is modulated by infants’ language background.

We are finalizing data from two age groups: 6-9 month-olds and 12-15 month-olds, which will be compared to those from monolingual infants from the same communities collected in our companion project, ManyBabies 1. Currently, 17 labs from 8 countries have registered to collect data, yielding a projected sample size of 192 bilingual 6-9 month-olds, and 192 bilingual 12-15 month-olds.(see Table 1 for details on participating labs including infant language backgrounds). Preliminary data are not available due to pre-registration policies on data peeking, but data collection is scheduled to end on August 31, 2018, and we will be excited to present our results at SRCD 2019.

Our results will not only be revealing with respect to experiential moderators of infants’ preference for IDS, but will also provide a model for how bilingualism researchers can collaborate to better understand this varied and under-studied population.

Authors

• Casey Lew-Williams, Princeton University
  Presenting Author

• Krista Byers-Heinlein, Concordia University
  Non-Presenting Author