Are bilingual advantages dependent upon specific tasks or specific bilingual experiences?

TLDR

Previous studies have found no consistent evidence for bilingual advantages in executive processing, with large‑scale investigations of highly fluent bilinguals reporting no benefits across age groups or tasks, though some researchers suggest advantages may be limited to specific bilingual populations. This study examines whether variations in second‑language exposure among a homogeneous sample of bilinguals affect executive function. Using a database of 168 bilinguals and 216 monolinguals, the authors compared executive function across groups defined by age of L2 acquisition, L2 proficiency, and number of languages spoken. Across 12 executive‑function measures, the study found no support for early bilingualism, balanced bilingualism, or trilingualism enhancing inhibition, monitoring, or switching, and any significant effects tended to contradict these hypotheses.

Abstract

Paap and Greenberg concluded that there is no coherent evidence for bilingual advantages in executive processing. More optimistic researchers believe that the advantages may be restricted to certain types of bilinguals. Recent large-scale and lifespan investigations that tested highly fluent bilinguals from communities where the same two languages are spoken by most residents reported no bilingual advantages in any age group or in any of the tasks used to measure executive functioning. The present study takes a complementary approach by examining a sample that is quite homogeneous in terms of current life experiences, but heterogeneous in terms of its exposure to second languages. The composite database of 168 bilinguals and 216 monolinguals is used to explore for differences based on: (1) the age of acquiring a second language (L2), (2) the relative proficiency of an L2 and (3) the number of languages used. Across 12 different measures of executive function, derived from 4 different nonverbal tasks, there was no consistent evidence supporting the hypotheses that either early bilingualism, highly fluent balanced bilingualism, or trilingualism enhances inhibitory control, monitoring or switching. In fact, when statistically significant effects did occur, they more often disconfirmed than confirmed these hypotheses.