It's the one that immediately set off my alarm bell. I always try to put myself in the shoes of a scientist and imagine how it would be possible to design a study to test a claim. To me, this one implies humans of today are worse at recognizing faces compared to humans of the past who did not read as much or at all. That one cannot possibly be tested because you cannot test the cognitive capabilities of people of the past who no longer exist.

On the more productive side, this suggests we might develop standardized tests of human capabilities and limits that would allow people of the future to compare themselves to us.

There are people who are illiterate today who you can test.