Read on Twitter
"One week following the implementation of universal masking on March 31, 2020, we observed a significant decrease in the cumulative incidence rate of healthcare-acquired SARS-CoV-2 infections among HCWs." Red line=hospital worker +. Purple=Duke hospitals masks up, end of March. https://twitter.com/Sonali_Advani/status/1304032204268470273
Also to the "nothing makes a difference" crowd: in March, health authorities were telling us masks were useless, and science journalist were publishing articles claiming masks were *harmful.* We had the evidence we needed by then, but not the public conversation. Then it changed.
One of the most striking aspects of groupthink is how a sudden lurch in group consensus can induce group amnesia. I knew of this from history but living through it in a pandemic has been personally mind-blowing. People have already forgotten the Feb/March information environment.
Of course, it's fine and good to change one's mind whether because of evolving evidence or simply because one concedes being wrong. It's an excellent habit: best of science happens that way. However, it's important to learn from what happened, not immediately erase the memory.
What makes the scientific enterprise valuable isn't because it has some special species of humans—immune to error or all the social, political, psychological and financial distortions—but that we try to set up the rules and rituals and rewards to work against that. That's it.
One reason for the "nothing makes a difference" crowd is cynicism is increasingly seen as if it's politics—instead of what it really is: resignation served in a fancy sauce. Another is this rapid amnesia. Yeah, nothing appears to change if we forget what happened this quickly.
