One of the smartest people I’ve met in my life is a plumber, who failed 5th grade and never went back to school. He can’t even read/write basic sentences in his native language and he can only speak one language, his native. Yet, he is able to figure out how to use all settings on smartphones on his own, plan plumbing for large properties, has high level people skills, is the president of his union etc. other than computers/scrabble, I am probably not even half as smart as this person, and I have a masters degree (for what it is worth).

All this to say, I don’t understand “number of books read” as a metric of smartness or literacy or intelligence. Maybe it is easier to survey this metric and collect data? Sounds lazy research to me.