First of all, as someone form a completely different field I like the style of the paper. Abstract and motivation are very consise and to the point with good re

First of all, as someone form a completely different field I like the style of the paper. Abstract and motivation are very consise and to the point with good references and it's very clear to me what they want to show and why. The method seems ok to me as well, internet based test taking with tests that sound reasonable to me (as a lay person, I have not idea what the typical tests in these studies look like). Statistics and control make sense to me. Overall, it's an interesting study. There were a couple of things I found interesting: 1) "the matched samples were constructed from individuals only in Canada, the United States, the United Kingdom, and Australia" which was due to the fact they didn't want to bias against people not understanding the instructions well (which were in Englisch). I'd be curious if it would be possible to find a large enough sample to reproduce the test with another base language for the instructions. Maybe French or German, Swiss citizen, parts of Italy (Südtirol), Luxembourg come to mind as natural bi- or multilinguals. 2) Going back to #1, I'm not entirely sure what criterion they used for bilingual (my understanding is just self identified by participant) but given that they used 18+ age due to ethical considerations this could be problematic. Maybe I'm wrong and they actually did it that way but I'd have prefered if they selected only people who learned the language from the parents because there's many people who speak Englisch as a second language but learned it in school/later in life but before 18. It might be interesting to redo the study with children before they are exposed to languages in school, maybe age <=10 or try to correct for this by removing the most likely "school language" Englisch. At least I suppose it's possible that there is a difference between growing up with a language and "learning" it more actively. 3) They removed outliers. However, it may be the case that bilinguals are more likely to be outliers ("gifted") than monolinguals. I don't know but I'd like to see just the outliers (140+32 if you use both 4+6 standard deviations). 4) Maybe someone with expertise in the area of neuroplasticity can chime in but the baseline takeaway from the paper is "there's no cognitive advantage to being bilingual". However, my layperson's understanding is that learning a language later in life will "reshape the brain" and possibly even use unused parts and so on which would indicate that there has to be some benefit vs. "just doing nothing". It would be interesting to know if learning a language is more beneficial vs. say taking up pottery. Alas this seems almost impossible to analyze in a meaningful way.