The Development of Translation Equivalents in Bilingual Preschool Children

The current study addressed a long-standing question regarding how bilinguals learn and represent two languages. Well-established measures including the MacArthur-Bates Communicative Development Inventory (MCDI), The Attention Network Test (ANT), and The Dimensional Change Card Sort task (DCCS) were utilized in combination with Individual Growth Curve (IGC) analyses for novel investigations into the development of bilinguals’ early productive vocabulary, especially translation equivalents (TEs) – two labels for the same concept in different languages – and their relation to cognitive control. These questions were addressed via two complementary studies. Study 1 examined longitudinal productive vocabulary data as collected by the MCDI from 98 preschool children – 38 bilingual (17 Spanish-English, 21 Vietnamese-English), and 60 monolingual (20 English, 20 Spanish, 20 Vietnamese) – with follow-up assessments every six months from ages 3 to 4 years, for a total of three time points per child. This investigation yielded a detailed description of early vocabulary development in monolingual and bilingual preschool children, and allowed for the examination of the development of TEs in bilinguals. In addition, Study 1 investigated the development of TEs in various linguistic contexts – across lexical category (e.g., nouns, verbs, and adjectives) and across specific bilingual language groups (e.g., Spanish-English and Vietnamese-English). Study 2 investigated the development of cognitive control – as measured by the ANT and DCCS – across language groups, and explored the potential relevance of cognitive control for the learning of TEs. Results from IGC analyses revealed that preschool children’s English vocabulary, non-English vocabulary, and conceptual vocabulary increased across development, but that monolinguals and bilinguals had different growth parameters for English and Vietnamese vocabulary. TEs were also found to increase across development, but growth rates differed in Spanish-English and Vietnamese-English bilinguals. A bilingual advantage was found for cognitive control, and cognitive control was found to be a significant predictor of number of TEs. Results are discussed in relation to the language and cognitive development literature in general, as well as the field of bilingualism in particular.