The original study was published on a pre-print server in August, but many people may have missed it since it wasn’t mentioned in the mainstream press at all.
On August 16, 2021, the BMJ published an article “Covid-19: Children born during the pandemic score lower on cognitive tests, study finds.” The original study, which is awaiting peer review, was funded by the National Institutes of Health, and conducted by a team of researchers at Brown and other U.S. universities.
The BMJ article pointed out:
In a longitudinal study of 672 children from Rhode Island that has run since 2011, those born after the pandemic began showed results on the Mullen scales of early learning that corresponded to an average IQ score of 78, a drop of 22 points from the average of previous cohorts.
So it was a normal IQ of 100 before. It’s dropped 22% from there. That’s huge.