Relationships between bilingual exposure at ECEC and vocabulary growth in a linguistically diverse sample of preschoolers

Earlier work has shown that bilingual Early Childhood Education and Care (ECEC) has positive effects on children's development of the minority language, and does not negatively impact on their development of the majority language. However, past studies leave unclear if these effects remain if home language exposure is taken into analysis. This study examines the effects of bilingual exposure at ECEC on vocabulary development in a linguistically diverse sample of 584 two- to four-year-old children attending bilingual (Dutch-English) ECEC in the Netherlands, taking into account the amount of exposure children received to Dutch and English at home. Latent Growth Modeling analyses showed that the amount of exposure to the non-majority language (English) at ECEC was positively related to children's growth of English receptive and expressive vocabulary. Amount of exposure to the majority language (Dutch) at ECEC did not bear significant relationships with growth of Dutch receptive and expressive vocabulary. The strengths of the relationships between the amount of Dutch and English exposure at ECEC and vocabulary development did not differ between two child groups depending on whether they were exposed to Dutch or English at home. Taken together, these results corroborate earlier effects of bilingual ECEC from small-scale studies for a larger sample, and indicate that these effects may remain if differences in home language exposure are taken into consideration.