In the 1980s, the New Zealand social scientist James Flynn discovered that IQs had been rising by about three points per decade. According to his findings, average IQs in 20 developed countries had increased by about 15 points during the previous 50 years. (That's in constant terms: IQ scores are periodically re¬scaled so that the average score is 100.) The increase was far too fast to result from genetic changes, so most researchers attribute it to an array of environmental influences: improved nutrition, more-challenging childhood games, better teaching methods, and even exposure to more media in the form of television and computers.
In the last decade, IQs in Denmark and Norway have failed to increase, and some worry that beneficial environmental influences on children are being reversed. In the July-August issue of the American Scientist, Michael Shayer, a psychologist at the University of London, sighs, "They're glued to bloody computer games." But Flynn himself notes that average IQ scores continue to rise in the United States, where American children are not known to avoid pernicious computer games.
Is it really plausible that in the absence of video games, IQs would continue to increase three points per decade for another century, so that by 2100 a person of average intelligence would score 145 on the 1950 scale? Flynn argues that, due to better and more stimulating environments, more and more people have been able to fulfill their genetic potentials. Beneficial influences in developed countries are likely reaching a saturation point, so a slowdown in the rate of IQ increase is no surprise.