People are getting dumber. So concludes a new study in the Proceedings of the National Academy of Sciences (PNAS): Using military conscription data from Norwegian males born from 1962 and 1991, the authors find that the secular increase in population intelligence observed throughout the 20th century has peaked and has now gone into reverse.
Average IQs, as measured on standardized intelligence tests, increased for most of the 20th century. This astonishing fact was first reported in 1984 by the New Zealand political scientist James Flynn.
[S]ome observers have suggested that average IQs are coming down because of dysgenic fertility—that is, because less intelligent people are having more children than smarter folks—or because of lower-IQ immigrants and their children. These trends, they argue, are now beginning to swamp the IQ-boosting effects that improvements in nutrition, education, and falling pathogen stress had during the 20th century.
If falling average IQ scores cannot be attributed to dysgenic or immigration effects, they must be the result of some environmental effects. But what? The researchers conclude that “our results remain consistent with a number of proposed hypotheses of IQ decline: changes in educational exposure or quality, changing media exposure, worsening nutrition or health, and social spill-overs from increased immigration.”
As George Mason University economist Tyler Cowan pithily puts it, “We have started building a more stupidity-inducing environment.”
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