Here is the IQ take for the day. As I have said, I am sceptical about IQ being conceptually able to capture a multi-dimensional phenomenon like human intelligence. But the Dissent Right, places like American Renaissance, love IQ, which they see as indicating the superiority of East Asians to whites. Anyway, they report on the occurrence of a “Reverse Flynn effect,” something observed to have begun in the 1990s. This is plausible, since there are now numerous factors that are undermining human health, such as chemical pollution, which will also lower intelligence, and hence IQ. The idea that the lower scores might indicate that people are getting worse at taking these tests, gives the game away, as it admits that the tests have a relative aspect to them rather than measuring some objective quality.
https://www.amren.com/news/2023/04/new-study-reveals-sharp-decline-in-american-iq-scores/