Who are the bilinguals (and monolinguals)?

In the keynote article, “Bilingualism and Cognition”, Valian (2014) has reviewed current research on comparing executive function (EF) in monolingual and bilingual individuals across the lifespan. The conclusion is that there are inconsistent EF advantages from bilingualism and all other cognitive challenging activities primarily because individual differences in these cognitive challenging experiences may collectively attribute to superior EF resulting in inconsistent EF benefit attributable to a single experience. In essence, variability in study participants’ experience and tasks contributes to the inconsistency in the behavioral outcomes observed in monolinguals and bilinguals. Notably, Valian suggests that monolinguals may also engage in other cognitively challenging activities, which have not been accounted for in individual studies, thereby resulting in improved EF similar in magnitude to that related to bilingual experience. Although it was not specified which cognitively challenging activity is more likely to be engaged by monolinguals more than by bilinguals, the question at heart is: is there an EF advantage that can be specifically attributed to bilingual experience? The review addressed in the keynote demonstrates seemingly inconsistent patterns of results. In this commentary, I would like to suggest that, in addition to task measurements, individual bilingual experience is dynamic and multifaceted. Moreover, bilingual experience varies in different communities. Consequently, one potential source of explanation for the inconsistent results in between-group EF performances is the characteristics of the bilinguals (and monolinguals) and their social environments included in these studies.