The study this summary refers to studied books as an indicator of a “culture of scholasticism.” It didn’t even really try to disentangle socioeconomic effects,

The study this summary refers to studied books as an indicator of a “culture of scholasticism.” It didn’t even really try to disentangle socioeconomic effects, because it was looking to use books as a proxy for them. It did not say “books in the home make you smarter.” It was arguing “books are a reasonable cross-cultural proxy for orientation towards scholasticism in the home.” This summary, to my reading of the actual article, completely confuses cause and effect.