Of course, writing systems are thousands of years old, found in ancient Sumer, China, and Egypt, but in most literate societies only a small fraction of people ever learned to read, rarely more than 10 percent. So, when did people decide that everyone should learn to read? Maybe it came with the rapid economic growth of the 19th century? Or, surely, the intelligentsia of the 18-century Enlightenment, imbued with reason and rationality, figured it out?
No, it was a religious mutation in the 16th century. After bubbling up periodically in prior centuries, the belief that every person should read and interpret the Bible for themselves began to rapidly diffuse across Europe with the eruption of the Protestant Reformation, marked in 1517 by Martin Luther’s delivery of his famous 95 theses. Protestants came to believe that both boys and girls had to study the Bible for themselves to better know their God. In the wake of the spread of Protestantism, the literacy rates in the newly reforming populations in Britain, Sweden, and the Netherlands surged past more cosmopolitan places like Italy and France. Motivated by eternal salvation, parents and leaders made sure the children learned to read.
By setting the incentives and defining the constraints, our culturally-constructed world shapes how we think, feel, and perceive—it tinkers with and calibrates the machinery of our minds.