Posted on March 7, 2018

Humanity Keeps Getting Smarter

Peter R. Orszag. Bloomberg, March 6, 2018

{snip} Norway and the other Nordic countries have seen an IQ downturn, admittedly from relatively high levels, even while intelligence measurements in the rest of the world continue their long upward rise. A key question is whether the recent downturn in Norway and elsewhere suggests the global phenomenon may soon end, too.

Average intelligence levels, as measured by standardized intelligence tests, have been rising since at least the early 20th century. A recent meta-analysis that included more than 4 million people in 31 countries found an average gain of about three IQ points per decade, or roughly 10 points per generation. Another recent study found a similar increase.

The phenomenon is commonly called the “Flynn effect,” after James Robert Flynn, the New Zealand academic who documented it in a series of studies starting in the early 1980s. The rise in IQ has been found in both developed and developing countries, but it varies by degree across countries, over time, and according to the type of intelligence measured. The Flynn effect has been stronger for nonverbal tests than for verbal ones, for instance, and greater for adults than for children.

{snip} More likely, multiple factors are at play, including improvements in nutrition; expansion of formal schooling; increases in average educational attainment; environmental improvements such as a reduction in lead exposure; and shrinking family size, which allows more focus on the education of each child. An ongoing debate exists about whether or not the increase in the average reflects a disproportionate increase in IQ levels at the bottom end of the distribution.


One notable exception to the sustained, worldwide rise in average IQ is found within the U.S. military: Officers’ test scores have declined in recent decades. Given that the IQ scores for the U.S. overall have continued to rise, the military results presumably reflect recruitment patterns rather than any broader phenomenon. What stands out is when average scores for a whole country decline.

Which brings us back to Norway. Nine studies have measured negative Flynn effects in seven countries, according to a recent systematic review of the literature. The data for Norway are particularly interesting, because they’re based on tests administered to military conscripts and cover a substantial share of young men in the country. They show declines in average IQ in Norway since the mid-1990s.

Professor Flynn himself has conducted some of the new research on Norway and other Scandinavian countries. His analysis suggests a decline of about 6.5 points per generation.

Might these declines eventually be echoed in the rest of the world, or are they specific to the countries involved? Presumably, the causes of the Flynn effect could diminish, and be overwhelmed by other forces — including the effects of video gaming and other recent social and cultural changes.