Predictors of verbal fluency performance in monolingual and bilingual children: The interactive role of English receptive vocabulary and fluid intelligence

Abstract

Introduction: Previous research has found that when bilingual and monolingual children are equated on English receptive vocabulary, bilingual children outperform monolingual children on verbal fluency tasks (e.g., Pino Escobar et al., 2018; Zeng et al., 2019). However, the locus of these differences in performance is poorly understood. The current study investigated the linguistic and cognitive components that underlie verbal fluency performance in bilingual and English-speaking monolingual children.

Methods: Students in fourth and sixth grade (63 bilinguals and 31 monolinguals) performed both category and letter fluency tasks in English where they named members of provided categories in one-minute trials (e.g., animals, words that start with "F", respectively). Participants also completed a battery of English language measures (e.g., English receptive vocabulary, English word reading fluency) and cognitive measures (e.g., fluid intelligence, working memory).

Results: Although monolinguals outperformed bilinguals on English receptive vocabulary, no group differences emerged on verbal fluency measures. When English receptive vocabulary served as a covariate, bilinguals generated significantly more items than monolinguals in the verbal fluency tasks. For monolinguals, only English receptive vocabulary accounted for unique variance in verbal fluency performance. However, for bilinguals, receptive vocabulary and fluid intelligence were significant predictors in both fluency tasks. Additionally, for bilinguals, fluid intelligence impacted the strength of the relationship between English receptive vocabulary and letter fluency performance; they were not significantly correlated for individuals with low cognitive ability and were strongly correlated for individuals with high cognitive ability.

Conclusions: Results suggest that unlike monolingual children, bilingual children recruit additional cognitive resources to meet the demands imposed by the verbal fluency task.

Keywords: Bilingualism; English receptive vocabulary; Fluid intelligence; Verbal fluency.