EXPERTS WERE SURE THAT THE 20TH CENTURY would make us stupid. Never before had culture and technology reshaped daily life so quickly, and every new invention brought with it a panic over the damage it was surely causing to our fragile, defenseless brains. Lightbulbs, radio, comic books, movies, TV, rock and roll, video games, calculators, pornography on demand, dial-up internet, the Joel Schumacher Batmans—all of these things, we were plausibly warned, would turn us into drooling idiots. ¶ The test results told a different story. In the 1930s, in the U.S. and across much of the developed world, IQ scores started creeping upward—and they kept on going, rising on average by roughly three points per decade. These gains accumulated such that even an unexceptional bozo from the turn of the…