There is so much coronavirus research coming out every day that it’s hard to keep track of even a tiny bit of it, never mind everything. The same is true for COVID-19 news — there’s just so much new information that it’s hard to stay up to date with it all, no matter how hard you might try.
It’s a bit like fighting a raging wildfire using your SuperSoaker 300. It’s never going to work, and you’ll eventually get burned.
One problem that keeps coming up is something that every scientist knows, but can be very counter-intuitive: the ecological fallacy. It’s present in arguments both for and against masks, it has undermined much of the discussion about vitamin D and coronavirus, and it’s just generally a problem for many of the points made in the media about COVID-19.
So what is the ecological fallacy, and why is it a problem? Let’s dig in.
While it may sound like biology, the ecological fallacy is actually about large populations rather than the biophysical environment. It is so simple and yet such and easy trap that pretty much everyone has fallen into it at one point or another.
The basic idea of the fallacy is this: you cannot directly infer the properties of individuals from the average of a group. Sounds complicated, but what that means is that if you measure something about lots of people — say, height — you can’t take the average measurement as an indication of any particular person’s status.
There’s a really simple example of this to do with means, or averages. Imagine you’ve got two groups of ten people, A and B. Group A has an average height of 170cm, and group B has an average height of 168cm. If you randomly select one person from each group, who is…