This difference, which is thought to be advantageous for bilingual infants, appears to be due to the fact that bilingual babies need to devote their attention to the general associations between words and objects (often a word in each language) for a longer period, rather than focusing on detailed sound information. This finding suggests an important difference in the mechanics of how monolingual and bilingual babies learn language.
These findings are from new research conducted at the University of British Columbia and Ottawa. They appear in the September/October 2007 issue of the journal Child Development.
Immigration, official language policies, and changing cultural norms mean that many infants are being raised bilingually. Because nearly all experimental work in infant language development has focused on children who are monolingual, relatively little is known about the learning processes involved in acquiring two languages from birth.
This later use of relevant language sounds (such as consonants) to direct word learning is due to the increased demands of learning two languages, the researchers suggest. Ignoring the consonant detail in a new word may be an adaptive tool used by bilingual infants in learning new words. Outside the laboratory, there is little cost to overlooking some of the consonant detail in new words, as there are few similar-sounding words in infants' early vocabularies. By paying less attention to the detailed sound information in the word, bilingual infants can devote more cognitive resources to making the links between words and objects.
Extending this approach to word learning for a few months longer than monolinguals may help bilinguals "keep up" with their peers. Indeed, previous research has shown that bilinguals and monolinguals achieve language-learning milestones (such as speaking their first word) at similar ages and have vocabularies of similar sizes when words from both languages are taken into account.
"Through studies with bilingual infants, we can gain a deeper understanding of language development in all infants," according to Christopher T. Fennell, assistant professor of psychology at the University of Ottawa and the lead author of the study. "In addition, the findings emerging from such studies will have practical implications for parents who are raising their children in a bilingual environment by revealing how young bilinguals acquire language."