Executive function skills account for a bilingual advantage in English word learning among low-income preschoolers

Abstract

The current study compared economically disadvantaged bilingual and monolingual preschoolers’ performance on measures of language and determined whether children’s executive function (EF) skills account for differences in novel word learning across groups. Thirty-nine English monolinguals and 35 Spanish-English bilingual preschoolers from low-income homes completed a battery of EF measures and the Quick Interactive Language Screener (QUILS) to gauge language abilities. Within a poverty context, bilingual and monolingual preschoolers did not differ in their English vocabulary knowledge, but bilingual preschoolers performed significantly better on measures of syntactic processing and word learning. This bilingual advantage in word learning ability was mediated by working memory, but not inhibition or attention shifting, which indicates that gains in working memory may facilitate word learning for bilingual preschoolers from economically disadvantaged backgrounds. These findings have important practical implications for interventions designed to promote vocabulary growth for low-income bilingual children.