The trend of rising intelligence is known as the “Flynn Effect,” named for James R. Flynn, the New Zealand scholar who pioneered this area of research. Countless other scholars worldwide have replicated his findings, and it is now accepted science — although there is still disagreement about its causes and significance.
The average American I.Q. has been rising steadily by 3 points a decade. Spaniards gained 19 points over 28 years, and the Dutch 20 points over 30 years. Kenyan children gained nearly 1 point a year. Those figures come from a new book by Flynn from Cambridge University Press called “Are We Getting Smarter?” It’s an uplifting tale, a reminder that human capacity is on the upswing. The implication is that there are potential Einsteins now working as subsistence farmers in Congo or dropping out of high school in Mississippi who, with help, could become actual Einsteins.
The Flynn Effect should upend some of the smugness among those who have historically done well in global I.Q. standings. For example, while there is still a race gap, black Americans are catching up — and now do significantly better than white Americans of the “greatest generation” did in the 1940s.
None of this means that people today are born smarter. While I.Q. measures something to do with mental acuity, it’s a rubbery and imperfect metric. It’s heavily shaped by environment — potential is diminished when children suffer from parasites or lead in air pollution. As a result, the removal of lead from gasoline may have added 6 points to the I.Q. of American children, according to Dr. Philip Landrigan, a pediatrician and epidemiologist at Mount Sinai School of Medicine.