We just keep getting smarter. That’s what James R. Flynn reports in The Wall Street Journal. He says that I.Q. tests, over the past century, suggest that Americans have gained three to five I.Q. points, on average, per decade.
Just for fun, let’s assume that his research is correct, and let’s take the lower estimate in order to keep our calculations conservative. Also, let’s assume that the changing I.Q. scores have been constant since the beginning of modern intelligence testing.
Actually, large-scale testing of mental abilities may have been part of the system in imperial China, when a high score was sufficient for anyone to be admitted to a “college” for potential upward mobility. In those days, the son of a peasant could theoretically become an advisor to the emperor. On rare occasion, we believe this really happened.
During the time that Charles Darwin was developing his theory of biological evolution, his friend Francis Dalton developed a method for measuring intelligence, which he called psychometrics. However, his “tests” were abandoned after it was shown that they had no correlation with the achievement of outcomes such as school or college grades...