Developmental trajectories of cognitive and metacognitive capacities in second-generation bilingual migrant and native monolingual children

The present study is a first attempt to jointly investigate a broad range of cognitive and metacognitive monitoring capacities in bilingual and monolingual children, focusing on bilingualism as a potential moderator of age-related developmental trajectories. Two understudied samples were assessed: a maintenance bilingualism group of early Albanian-Greek bilingual children (second-generation migrants) and Greek-speaking (native) monolingual peers (145 children aged 8;4–12;10). Cognitive domains assessed included attention, inhibition, shifting, updating, working memory capacity, and planning, and metacognitive monitoring measures (prospective and retrospective estimates of performance and task ease) were also obtained. Frequentist and Bayesian moderated regression analyses were conducted, controlling for non-verbal intelligence and parental SES. Beyond the expected age-related improvements in cognitive and metacognitive abilities, the analyses showed only three moderating patterns: more accurate monitoring of task demands (as indicated by global speed in the attention task) with age, but only among monolinguals; age-related improvements in non-verbal planning and the accuracy of related prospective ease judgments, both observed only among bilinguals. Bilingual children also showed lower accuracy than monolinguals in proactive ease estimations in the attention task. Overall, the findings challenge claims of general bilingual advantages in executive function and their developmental nature, extending null results to metacognitive monitoring. The evidence supports a close interplay between developing cognitive and metacognitive functions—both central to the top-down regulation of thought and action toward goal-directed behaviour. The discussion underscores the need to explore how individual and contextual factors interact to shape cognitive and metacognitive development in childhood.