A large and ever-growing body of research has shown that individuals who know more than one language (bilinguals and multilinguals) process, store, and understand language(s) differently from those who know only one. Bilingual children often demonstrate a higher degree of metalinguistic awareness than their monolingual peers in areas such as word-meaning connection, phonology or morphology. Differences between monolinguals and bi/multilinguals (of all ages) have also been found in areas of cognition that extend beyond the language domain, such as cognitive flexibility and executive function (EF). However, such studies have predominantly focused on native and/or fairly proficient bi/multilinguals; less is known about the effects of partial or emerging bilingualism. Moreover, only very few studies have looked at the development of these abilities over time.
The MAYLL study (Metalinguistic abilities in young language learners) included some 100 pre-school children from German-speaking families, about half of whom attended kindergartens with some form of intensive English immersion or bilingual program. Most children in the longitudinal cohort entered the project around age 4-5 and were tested three times over a period of two years, and a smaller group was tested only once at age 6, in the childrens final months of pre-school. Monolinguals and young foreign language learners were matched on age, parental education, and general intelligence/working memory, and given several tests of metalinguistic ability, as well as of verbal and nonverbal executive function.
No significant performance differences were found between monolinguals and emerging bilinguals among the once-tested six-year-olds, but there were several differences within the longitudinal cohort. These, however, were not stable, but changed over time: A higher willingness among the very youngest partial bilinguals (age 3-4) to use different or nonsense names for familiar objects disappeared at subsequent test times. The partial bilinguals were also significantly better on certain measures of verbal and nonverbal EF and metalinguistic awareness, but only at the final test time. The most surprising finding of the study is that improvement with repeated testing was very different between language groups: At age 6, there were no significant differences among the monolinguals between ‘first-timers and ‘third-timers, but among the emerging bilinguals, the ‘repeaters scored significantly higher than the ‘novices on several of the tests. In other words the young language learners appear to have benefitted more from repeated testing (practice effect) than the monolinguals.