Research teams studying bilingualism often focus on a specific population of bilinguals, which can limit the generalizability of their findings. This study explored how U.S. adolescents who speak a non-English language vary in their language experiences and cognition using data from the Adolescent Brain Cognitive Development (ABCD) study. The sample included 6683 English monolinguals, 1138 heritage bilinguals, 592 dual language education (DLE) bilinguals and 1751 other bilinguals. SES varied across groups: sequential bilinguals (i.e., DLE and other bilinguals) had higher parental education and income than monolinguals, while heritage bilinguals had the lowest SES. Sequential bilinguals reported higher English proficiency and greater English use with family and friends than heritage bilinguals. Sequential bilinguals initially outperformed monolinguals on cognitive tasks, who in turn outperformed heritage bilinguals. However, these differences disappeared once SES was controlled. Findings highlight the importance of considering SES and language experiences when studying bilingualism’s cognitive effects and help explain inconsistencies in prior research.
