THE WORLD IS GETTING SMARTER | More Intelligent Life

If each of a pair of tests was supposed to be equally closely related to innate intelligence, how could people have got so much better at one of them but not the other? It was this puzzling patchiness that started Flynn thinking along the right lines. He likes to use sporting analogies to illustrate his ideas. Suppose we had long been in the habit of subjecting children to a battery of tests for athleticism: long jump, high jump, sprint, and so on. As with mental abilities, so physical abilities would tend to be linked. Someone who can run fast can usually also run a long way, and jump high and far. So we could calculate a “physical g”. But over time priorities change. Satellite television becomes widespread; broadcasters bid up the rights to athletic events; advertisers find that some events attract viewers so they pay more for those events and sponsor the athletes who excel at them. The 100-metre sprint, say, becomes the most popular event in schools and sports clubs; training improves. Even though human bodies and human genes have not changed, and even though excellence in sprinting is still just as closely related as it ever was to excellence in other events, sprinting improves massively, whereas performance in other events barely changes.