Parents who raise their children bilingual can be concerned that early exposure to two languages will lead to confusion, an inability to separate the languages, and a delay in cognitive development.
Underlying this concern is a belief that dual language learning in early childhood places additional burdens on language development, compared to learning a single language.
There have been relatively few studies evaluating the development of bilingual children, despite a burgeoning literature on child cognitive development more generally.
A new Life Course Centre Working Paper aims to fill this gap by tackling the question of whether bilingual children achieve different outcomes in language and emotional development.
Authored by Deborah Cobb-Clark, Colm Harmon and Anita Staneva of The University of Sydney School of Economics, the paper takes advantage of the longitudinal structure of the UK Millennium Cohort Study data to investigate how the bilingual gap evolves from early childhood to adolescence.
They find that, based on age-specific analysis, younger bilinguals have lower levels of language development, but by age seven they have an advantage, and by age 11 they are back to having lower language development than their monolingual peers.
Ultimately, the most important overall finding is that bilingual children are not significantly different when compared with their monolingual peers in language development. However, the authors do find evidence of long-term positive effects of bilingualism on emotional development, particularly among boys and children of lower-educated parents.
With arguments promoting second language learning in school from a relatively young age as a means to promote economic competitiveness and growth, the lack of any gap in language and emotional development for bilingual children is significant, the paper concludes.
You can read the full Working Paper here.