The effects of second language proficiency and linguistic distance on cognitive abilities in bilingual children

Bilingual speakers have shown better performance than their monolingual peers on tasks that examine a range of cognitive abilities (e.g. attention, phonological awareness); however, other studies report no group differences. Two reasons may explain the inconsistencies across studies: 1) many studies did not examine and control, when needed, group differences in cognitive abilities that could influence performance on the ability in question; 2) variability in the language proficiency and linguistic similarity between first (L1) and second (L2) language. The current project examined language-related cognitive abilities (i.e. phonological awareness) and general cognitive abilities (i.e. attention and inhibition) in two studies of 8-10 year-old children in Hong Kong. Study 1 investigated whether these abilities, as well as reading, were affected by bilingualism and L1-L2 linguistic distance. There were three groups: English monolingual, Cantonese- English bilingual, and European language-English bilingual. All children had similar educational backgrounds, as they attended English speaking International schools. Particular effort was made to control for group differences in cognitive abilities that could act as confounding variables, which included: intelligence, English proficiency, working memory, and short-term memory. There were no group differences on the tasks of attention and inhibition. However, there were for phonological awareness and reading. L1-L2 linguistic distance provided an advantage over the monolinguals on phonological awareness as only the European bilinguals group performed better than the monolinguals. Whereas, bilingual children of linguistically distant L1- L2 (Cantonese-English) demonstrated difficulty with phonological awareness and reading tasks using nonwords but not real words compared with the other groups. The results suggest that children who speak two linguistically distant languages may have difficulty transferring L2 skills from familiar words to novel words, which is a skill needed in literacy development. Study 2 explored the influence of L2 proficiency on the two sets of abilities. The data from the English monolingual and Cantonese bilingual group in Study 1 was analyzed with data from a new group of children, those who spoke Cantonese (L1) and were learning English as a L2 (ESL). Once again, particular effort was made to statistically control for cognitive abilities that could act as confounding factors. The results of the general cognitive abilities show no group differences. The results of the phonological awareness task show that the ESL group performed worse than the English monolingual and Cantonese bilingual group. This was explained by their low L2 proficiency, as well as difference in the instructional method of English reading. The results of this project advance our understanding of bilingualism. Bilingual advantages are not observed in all children learning a L2 but are influenced by factors embedded in bilingualism (i.e. L2 proficiency, L1-L2 linguistic distance). This highlights that the effects of bilingualism need to be qualified. Additionally, bilingualism does not produce wide-spread advantages; rather, the influence of speaking two languages can affect one cognitive domain, such as language-related abilities, but not the general cognitive abilities within the same groups of children. The results are discussed in relation to the larger body of work and direction of future work is suggested.published_or_final_versionSpeech and Hearing SciencesDoctoralDoctor of Philosoph