by Amanda Eads and Amy Lebkuecher
There are lots of good ways to raise bilingual children, but unfortunately, many people worry that raising children to be bilingual may be harmful for their language development. In this piece, we summarize some research that clearly dispels this myth. For starters, while some people think that bilingual babies get confused when they hear different languages, the research shows that they’re actually quite adept at sorting through this variable input. In fact, bilingual infants can typically identify vowels and consonants in each of their languages by the age of one.1 To explain how they do this, researchers have hypothesized that bilingual babies separate their two languages from the beginning using characteristics of the speech signal such as rhythm.
A 2001 study in Spain explored how and when Spanish-Catalan bilingual infants distinguish their two languages, comparing them with monolingual Catalan and monolingual Spanish infants.2 The researchers found that at 4 months old, all the infants (and not just the Spanish-Catalan bilinguals) were able to differentiate between Spanish and Catalan. In a second experiment, the researchers included English, which was unfamiliar to all the infants in the study. They discovered that the bilingual and monolingual infants were using different strategies to distinguish between languages. The monolingual infants oriented to the languages they had previous exposure to (Spanish or Catalan), while bilingual infants oriented to the unfamiliar language (English). Researchers hypothesize that this difference in attention is what allows bilinguals to accurately determine later in development which language is appropriate to use in a given context.
Since bilingual infants hear people speaking different languages, as opposed to one language all the time, the amount of exposure they receive to each of their individual languages turns out to be less than the amount of individual language exposure monolingual babies receive. As a result, bilingual babies may initially appear “slow” to acquire their languages. This “slowness” may show up in vocabulary development: young bilingual children may appear to know fewer words in a single language overall than their monolingual counterparts. However, when compared to monolingual children of equal overall language ability, who are not necessarily the same age, this apparent disadvantage disappears. And while their vocabulary understanding may be slightly lower than that of their monolingual peers, there are other domains in which bilinguals may have the advantage. For example, bilingual children tend to outperform monolingual children on cognitive tasks that do not involve language, but which have a greater need for inhibition and control.3,4
So, are children confused by dual language input? The research summarized above gives a pretty resounding no to this question, and reveals just how adept typically developing children are at sorting through language input. While there may be some delays in vocabulary development in a single language for bilinguals, the potential cognitive and the many social benefits of bilingual language acquisition, including the ability to engage with more than one language community, may ultimately outweigh any potential drawbacks.
- Werker, J. F., & Byers-Heinlein, K. (2008). Bilingualism in infancy: First steps in perception and comprehension. Trends in cognitive sciences, 12(4), 144-151.
- Bosch, L., & Sebastián-Gallés, N. (2001). Evidence of early language discrimination abilities in infants from bilingual environments. Infancy, 2(1), 29-49.
- Kovács, Á. M., & Mehler, J. (2009). Cognitive gains in 7-month-old bilingual infants. Proceedings of the National Academy of Sciences, pnas-0811323106.
- Bialystok, E. (2011). Coordination of executive functions in monolingual and bilingual children. Journal of experimental child psychology, 110(3), 461-468.
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