Multilingualism and Working Memory: The Role of Formal vs. Informal Language Learning

The impact of multilingualism on executive functioning remains a topic of debate, with prior research suggesting minimal effects and limited real-world benefits. This study investigated whether multilingualism is related to performance and examined the role of formality in language acquisition (formal vs. informal) in modulating this relationship. A sample of 116 adults completed six working memory tasks and a language experience questionnaire, from which degree of multilingualism and formality of language acquisition were computed, using an entropy equation and a newly developed metric. Two different approaches were used to quantify formal and informal language learning: one that weighted language proficiencies using our new metric and another that categorized experiences using cut-off derived from such metric. The internal structure of measures underlying the working memory component was determined using principal component and parallel analyses, and regression models controlled for age, sex, and education. We found that a numerical-verbal working memory component explained 47.11% of the variance. No significant association emerged between overall multilingualism and working memory. However, at certain thresholds of the acquisition formality metric we developed, formal language acquisition was positively correlated with working memory, while informal acquisition was negatively related. Results support the idea that the relationship between multilingualism and working memory is nuanced, with formality of language acquisition modulating it. Future research should address the mechanisms underlying this complex relationship (e.g., causality, learning and memory mechanisms underlying formal versus informal learning and their relationship with executive function, etc.), and should consider acquisition formality as an important key variable in modulating multilingualism’s cognitive effects.