On Thursday last week, The Guardian published an article claiming that a new global study had demonstrated that mask-wearing cuts COVID incidence by 53%. The reddit thread discussing the article was littered with mildly smug comments: one user wrote “This’ll please those anti-maskers”, and promptly received the reply “Bbbbut they can’t breeeeeathe in a mask”. As someone who is emphatically pro-mask, I dislike these sorts of comments for a couple of reasons — firstly, they’re the sort of pointless in-group signalling that I imagine is very unlikely to persuade anyone who is actually a convinced anti-masker (although I think it is possible that this sort of signalling hardens the stance of people who are just
In my small sample size, my experience is that you're often stuck either way. When studies that overstate the effect are used, the error is obvious and undermines the point being made. However when studies that show the smaller real effect are used, they are discounted because the effect size is too small.. and knowing that it's possible to overstate the effect, these get discounted as evidence without biased individuals feeling the need to find a flaw in the study that backs up their view that they are overstating the effect. In many ways, when trapped in that sort of circular loop, the ones that overstate the effect come out better.. because even though their error is obvious, they have the defense that while it's may not be 53%.. surely there must be 10% left!