Read on Twitter
@EmilysNichols, @Comadork
Some thoughts about the recent Nichols et al., 2020 paper on bilingualism. 1) Using one or two questions to define bilingualism is *highly* problematic - akin to asking a person if they feel down & diagnosing depression https://journals.sagepub.com/doi/suppl/10.1177/0956797620903113 1/n
Some thoughts about the recent Nichols et al., 2020 paper on bilingualism. 1) Using one or two questions to define bilingualism is *highly* problematic - akin to asking a person if they feel down & diagnosing depression https://journals.sagepub.com/doi/suppl/10.1177/0956797620903113 1/n
See e.g., for validated bilingualism questionnaires used by experts: https://www.ncbi.nlm.nih.gov/pubmed/28281208 , https://bilingualism.northwestern.edu/leapq/ , and https://www.cambridge.org/core/journals/bilingualism-language-and-cognition/article/language-history-questionnaire-lhq3-an-enhanced-tool-for-assessing-multilingual-experience/B79893AD7B4AEA5EEF8344489B80023E, and https://www.cambridge.org/core/journals/bilingualism-language-and-cognition/article/characterizing-the-social-diversity-of-bilingualism-using-language-entropy/BCA277F72A02D8834C53E4F9090FF7FD
These measures have the advantage of being well-validated, and *continuous* thus allowing us to move beyond simplistic group comparisons. Group comparisons introduce variance as noise. We can capitalize on this variance by scaling bilingual measures.
2) Bilingualism is far more complex than a single number. Concepts such as Age of Acquisition (of the second language), proficiency, usage, and language switching are among the minimum variables to consider when determining who is bilingual and to what degree.
3) Bilingualism and by proxy its impacts on cognition *changes* depending on the language context. https://www.cambridge.org/core/journals/bilingualism-language-and-cognition/article/studying-bilinguals-methodological-and-conceptual-issues/344F4231E25225A1EDD9BC253B441792 and here... https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4095950/
4) the sample is of young adults - this sample tends to be at ceiling on many cognitive tests, and multiple studies now have found that bilingual and monolingual young adults perform similarly - so this isn't new (e.g., from Bialystok 15 years ago https://www.researchgate.net/publication/249840088_Bilingualism_across_the_Lifespan_The_Rise_and_Fall_of_Inhibitory_Control)
5) The tasks chosen don't necessarily tap into prospective and retrospective control jointly in a way that the AX-CPT task does, for example. There is good evidence that both forms of control are impacted by bilingualism, and we should measure both: e.g., https://www.ncbi.nlm.nih.gov/pubmed/29727624
... and https://www.ncbi.nlm.nih.gov/pubmed/28273520 , and https://sites.psu.edu/bildlab/files/2019/11/Zirnstein-VanHell-Kroll-2018.pdf.
In sum, the field of bilingualism has moved away from asking the "yes/no" question of whether or not there is a bilingual advantage. Bilingualism is not a categorical variable (Luk et al., 2013) https://www.ncbi.nlm.nih.gov/pubmed/24073327 . It is unhelpful to continue beating this dead horse problem
