Compared to monolingual people, bilingual people are generally considered to have a cognitive advantage related to executive function (EF). A recent meta-analysis conducted by Gunnerud and colleagues investigated whether bilingual children had an advantage in EF by examining different components of inhibition, switching, attention, monitoring, working memory, and planning.
100 publications (between 1980 to 2017) were identified, which included 143 group comparisons and 583 effect sizes. The bilingual advantage was statistically significant in overall EF (ES=+0.06). The study further performed a moderator analysis to investigate whether a cognitive advantage could occur under certain conditions. Regarding sample characteristics, the results showed that:
- Socioeconomic status (SES) difference was a significant moderator variable, and middle-class SES children had a greater bilingual advantage than lower-class children (β=0.235; p =.017) and upper-middle-class children (β=0.230; p =.046).
- Also, results from one lab showed a significantly larger effect than the studies from other labs (β=0.153; p =.011).
- In terms of the EF components, compared with attention, higher bilingual advantage effects were shown in monitoring (β=0.197; p =.004), switching (β=0.283; p <.001), and inhibition (β=0.290; p =.011). In contrast, working memory showed a lower bilingual advantage compared with attention.
- However, after controlling small-study effects and publication bias, only switching remained a significant bilingual advantage.
Thus, the authors raised a discussion about the existing hypothesis that bilingualism had a cognitive advantage related to EF. Limitations and further directions were also discussed.