title: Does language dominance affect cognitive performance in bilinguals? Lifespan evidence from preschoolers through older adults on card sorting, Simon, and metalinguistic tasks.
abstract: This study explores the extent to which a bilingual advantage can be observed for three tasks in an established population of fully fluent bilinguals from childhood through adulthood. Welsh-English simultaneous and early sequential bilinguals, as well as English monolinguals, aged 3 years through older adults, were tested on three sets of cognitive and executive function tasks. Bilinguals were Welsh-dominant, balanced, or English-dominant, with only Welsh, Welsh and English, or only English at home. Card sorting, Simon, and a metalinguistic judgment task (650, 557, and 354 participants, respectively) reveal little support for a bilingual advantage, either in relation to control or globally. Primarily there is no difference in performance across groups, but there is occasionally better performance by monolinguals or persons dominant in the language being tested, and in one case-in one condition and in one age group-lower performance by the monolinguals. The lack of evidence for a bilingual advantage in these simultaneous and early sequential bilinguals suggests the need for much closer scrutiny of what type of bilingual might demonstrate the reported effects, under what conditions, and why.
authors.affiliation: Linguistics Program, English Department, Florida International University Miami, FL, USA.
authors.forename: Virginia C Mueller
authors.initials: VC
authors.lastname: Gathercole
authors.affiliation: School of Education, Bangor University Bangor, UK.
authors.forename: Enlli M
authors.initials: EM
authors.lastname: Thomas
authors.affiliation: School of Education, Bangor University Bangor, UK.
authors.forename: Ivan
authors.initials: I
authors.lastname: Kennedy
authors.affiliation: School of Social Sciences, Bangor University Bangor, UK.
authors.forename: Cynog
authors.initials: C
authors.lastname: Prys
authors.affiliation: School of Education, Bangor University Bangor, UK.
authors.forename: Nia
authors.initials: N
authors.lastname: Young
authors.affiliation: State Key Laboratory of Brain and Cognitive Sciences, University of Hong Kong Hong Kong, China.
authors.forename: Nestor
authors.initials: N
authors.lastname: Viñas Guasch
authors.affiliation: School of Psychology, Bangor University Bangor, UK.
authors.forename: Emily J
authors.initials: EJ
authors.lastname: Roberts
authors.affiliation: School of Psychology, Bangor University Bangor, UK.
authors.forename: Emma K
authors.initials: EK
authors.lastname: Hughes
authors.affiliation: School of Psychology, Bangor University Bangor, UK.
authors.forename: Leah
authors.initials: L
authors.lastname: Jones
keywords: Simon task; Welsh bilinguals; bilingual children; dimensional change card sort task; executive function; language balance; language dominance; metalinguistic task