An analysis of people who were hospitalised with covid-19 in the first wave of the pandemic has revealed that the ongoing decline in their cognitive abilities is the equivalent to losing 10 IQ points
The cognitive abilities of people who were hospitalised with covid-19 during the first wave of the pandemic remain lower than expected, even years later, and there is some evidence that this is forcing them to change jobs.
“What we found is that the average cognitive deficit was equivalent to 10 IQ points, based on what would be expected for their age, et cetera,” says Maxime Taquet at the University of Oxford.
IQ tests seem like they would actually be useful here though had they done pre-Covid tests and at least a couple of them. I’m not an expert but it seems like the thing they’re bad at is quantifying in specific amounts the intelligence of a person.
For instance, we can’t say that if someone’s IQ went from 100 down to 80 that they became 20% less intelligent. But we can maybe say that this suggests that they lost some cognitive ability and then we can characterize that against a population without long Covid. And again we couldn’t say they’re 20% worse than someone without long Covid, but we certainly know that losing 20 points on an IQ test isn’t normal.
Losing 20 points of IQ is massive. That’s two standard deviations worth. It’s going from average to bottom of the barrel.