Bilinguals outperform trilinguals in implicit language aptitude: the mediating role of selective attention

A mounting number of individuals engage in the simultaneous learning of multiple foreign languages. Prior research has underscored the advantages of bilingualism on foreign language aptitude (FLA). However, the impact of multilingual experience on the constituents of FLA, namely explicit language aptitude (ELA) and implicit language aptitude (ILA), along with the cognitive mechanisms underlying these effects, remain less explored. This study seeks to fill this gap by examining the potential multilingual influence on FLA constituents and the possible mediating role of cognitive abilities such as selective attention and working memory. Our research involved 82 Chinese college students, aged between 17 and 24, equally distributed into two cohorts: Chinese-English bilinguals and Chinese-English-Japanese trilinguals (41 per group). The results showed that bilinguals outperformed trilingual learners in terms of ILA performance, with selective attention fully mediating the relationship between multilingualism and ILA. This work is pioneering in identifying the crucial role of selective attention in linking multilingualism and ILA, thereby advancing our understanding of the cognitive underpinnings of the relative bilingual efficiency in language aptitude. The insights are invaluable for educational practice, suggesting that language learning programmes should be designed to optimise cognitive resources in multilingual learners.