Do the people not wearing masks and flaunting restrictions simply not get it? No, they don’t, according to a new study in PLoS One, which finds that most people wildly misjudge how much impact their behavior can have on case numbers.
At issue is the concept of exponential growth, which is best illustrated by the well-known (in math circles, anyway) wheat and chessboard problem: If one grain of wheat is placed on the first square of a chess board, two on the second, four on the third, and so on, how many grains of wheat will be on the final square of the chessboard?
I guessed 8 million.
The answer is more than 18 quintillion.
Previous studies have found that even people who are quite familiar with the concept of exponential growth (like me) severely underestimate it in practical scenarios. (I was incorrect by a factor of, oh, 2.2 trillion.)
In this study, 400 Swiss participants were told about a country’s 1,000 virus cases, which jump up by 26% daily. But social distancing and other precautions can drop the daily increase to just 9%.
As expected, more than 90% of the participants dramatically underestimated the number of infections after 30 days, and the median participant believed that 8,600 cases would be prevented by social distancing. In fact, nearly 1 million cases would be prevented.
The good news is that people—or at least the ones in this study—did a winning job of comprehending the situation when it was explained in terms of doubling, as in “case numbers double every six days.” When time was introduced, participants understood the situation even better. For example, if everyone social distances, cases will double every eight days, as opposed to every three days, which gives us 50 extra days to stock hospitals before all hell breaks loose.
The take-home is think of your social distancing as saving millions from disease.
Also, the researchers want the media and public health officials to stop reporting just case numbers and instead, quantify the pandemic in terms of case doubling and time gained.