Defining bilingualism as a continuum: Some tools and consequences for the study of bilingual mind and brain effects

Abstract

Prior to the early 1960s, the idea that children in bilingual contexts were somehow disadvantaged for linguistic and cognitive development was popularly held. Without consideration of socio-economic inequalities across groups, often co-occurring with ethnic/racial minority status, it was argued that simultaneous language exposure resulted in confusion, delaying the process of language acquisition and cognitive development, if not, in the extreme, causing mental retardation (Goodenough, 1926; Saer, 1923). In light of what we know today— i.e., minimally, that bilingualism provides no disadvantage relative to monolingualism, a discussion to which we return in greater detail below (see e.g., Meisel, 2011, Serratrice, 2013, Bialystok, 2016, 2017)— it boggles the mind how such ideas could have originated, much less propagated. Perplexity, as is often the case, is only made possible by the clarity of hindsight. In some sense, claims about the extreme disadvantages of bilingualism were effectively inevitable. Simply put, the science of the times did not know better; it was fundamentally flawed.