Cognitive effects of bilingualism: digging deeper for the contributions of language dominance, linguistic knowledge, socio-economic status and cognitive abilities

Abstract

This study explores the extent to which a bilingual advantage can be observed for executive function tasks in children of varying levels of language dominance, and examines the contributions of general cognitive knowledge, linguistic abilities, language use and socio-economic level to performance. Welsh–English bilingual and English monolingual primary school age and teenage children were tested on two executive function tasks, a tapping task and a Stroop task. Bilingual children came from homes in which only Welsh, Welsh and English, or only English was spoken.

Results differed by task. On the tapping task, bilingual children from only Welsh homes showed overall superior performance, monolinguals inferior, with the other two bilingual groups between them. Performance correlated with general cognitive abilities with number and pattern discrimination, as well as, at the older age, with balanced use of the two languages. On the Stroop task, language tested mattered; there were no differences across groups in Welsh, but complex patterns in English. The only strictly bilingual advantage on the Stroop was at the younger age for children from Welsh and English homes when tested in English, and performance was also influenced by SES level, cognitive abilities, vocabulary levels and use of the two languages.

Keywords:

• executive function
• language balance
• language dominance
• tapping
• Stroop
• Welsh bilinguals

Acknowledgements

This research was supported by ESRC grant RES-062-23-0175 on Cognitive effects of bilingualism across the lifespan and by ESRC/HEFCW grant RES-535-30-0061 for the ESRC Centre for Research on Bilingualism in Theory and Practice, which we gratefully acknowledge. We also wish to express our thanks to all of the schools, parents and children who participated in this work; without their very helpful cooperation this study could never have taken place. Thank you also to project students and research assistants who helped in data collection: Carys Blunt, Angela H. Clifford, Lowri Cunnington, Nikki Davies, Sinead Dolan, Susan D. Elliott, Katie Gibbins, Bethan Gritten, Lowri Hadden, Josselyn Hellriegel, Catherine L. Hogan, Siwan Long, Jason H. McEvoy, Sarah N. Pearce, Hannah Perryman, Emily Roberts, Sioned Roberts, Kathryn Sharp, Heather Shawcross, Lesley Waiting.