Childhood Bilingualism

Research has shown positive effects of bilingualism on the following metalinguistic abilities: early word distinction; sensitivity to language structure and detail; detection of ambiguities; correction of ungrammatical sentences and detection of language mixing and control of language processing.

However, an important question remains unresolved, that is no explanatory model of how or why bilingualism has such positive effects has yet been developed or tested. So far, it is not clear, for example, how bilinguals' metalinguistic skills are related to advantages in cognitive abilities not directly related to language, such as classification or visual skills.

Another hypothesis put forward by Peal and Lambert (1962) stated that the possibility of switching linguistic codes while performing cognitive tasks gave bilingual children an added flexibility that monolingual children did not enjoy. This hypothesis gave rise to a popular concept regarding bilinguals' cognitive advantages, namely, bilinguals' cognitive flexibility. Even though some researchers have suggested caution in the interpretation of results on account of methodological shortcomings, the consistency of positive findings across different samples, measures, and research designs provides substantial support to the above hypotheses.

In another longitudinal study of the effects of bilingualism on cognitive ability, Hakuta (1987) made repeated observations of children's language and cognitive abilities over a three-year period. The sample consisted of approximately 200 Puerto Rican children enrolled in bilingual-education programs, where both the first (Spanish) and second (English) languages were used substantially as media of instruction. At the beginning of the study, the youngest subjects attended kindergarden and at the end of the study, the oldest children attended sixth grade.

The most striking finding of Hakuta's study is that bilingualism (defined as bilinguals' ability in the second language controlling for relative ability in the first language) predicts substantial portions of the variance in cognitive ability for younger children in kindergarten and first grade while the ...