TIL

“Literacy changes people’s biology and psychology without altering the underlying genetic code. A society in which 95 percent of adults are highly literate would have, on average, thicker corpus callosa and worse facial recognition than a society in which only 5 percent of people are highly literate.
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Literacy thus provides an example of how culture can change people biologically independent of any genetic differences.
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highly literate societies are relatively new, and quite distinct from most societies that have ever existed. This means that modern populations are neurologically and psychologically different from those found in societies throughout history and back into our evolutionary past.”

--- Joseph Henrich. “The WEIRDest People in the World.”

Human Capital & Behavioral Economics, circa 1st century BC

And though he owned numberless silver mines, and highly valuable tracts of land with the labourers upon them, nevertheless one might regard all this as nothing compared with the value of his slaves; so many and so capable were the slaves he possessed, — readers, amanuenses, silversmiths, stewards, table-servants; and he himself directed their education, and took part in it himself as a teacher, and, in a word, he thought that the chief duty of the master was to care for his slaves as the living implements of household management.

7 And in this Crassus was right, if, as he used to say, he held that anything else was to be done for him by his slaves, but his slaves were to be governed by their master. For household management, as we see, is a branch of finance in so far as it deals with lifeless things; but a branch of politics when it deals with men.

--- Plutarch, Lives. Crassus: 6-7.
https://penelope.uchicago.edu/Thayer/E/Roman/Texts/Plutarch/Lives/Crassus*.html