Historic decline in IQ could stem from poor education, study shows

A recent study suggests that, for the first time in nearly 100 years, Americans’ average intelligence quotient (IQ) is declining. 

The professors who authored the study theorize that the quality of education could play a role in reversing the IQ gains enjoyed by previous generations.

The study, published in a spring 2023 edition of Intelligence, measures IQ test results among 18- to 60-year-olds to examine the phenomenon first observed by philosopher James Flynn. 

Professors from Northwestern University in Evanston, Ill., and the University of Oregon in Eugene explain the Flynn effect: starting in 1932, average IQ scores increased roughly three to five points per decade. In other words, “younger generations are expected to have higher IQ scores than the previous cohort.”

Data from the sample of U.S. adults, however, imply that there is a reverse Flynn effect. From 2006 to 2018, the age groups measured generally saw declines in the IQ test used by the study, the International Cognitive Ability Resource (ICAR).

Overall declines held true across age groups after controlling for educational attainment and gender, but the study shows that the loss in cognitive abilities is steeper for younger participants. “[T]he greatest differences in annual scores were observed for 18- to 22-year-olds,” the authors write. 

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Exposure to education, including through obtaining a four-year degree, generally lessened the blow to IQ points. The study suggests, however, that this is less so for younger participants. “[E]xposure to education may only be protective for certain age groups,” according to the authors.

They continue to theorize that “a change of quality or content of education and test-taking skills” could explain the difference education makes in the IQ of younger versus older Americans. 

Millennials–the main age group completing their K-12 and college education during the study–have experienced vast changes in the education system. These include students learning to read from an influential but defective curriculum and students receiving inflated grades from their professors. Grade inflation, as Campus Reform noted, is a possible response to the idea that all students–no matter their ability or preparedness–must attend college.

The study also implies differences in younger Americans’ skill set, an observation made by Higher Education Fellow Nicholas Giordano. 

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The authors say that “scores were lower for more recent participants across all levels of education.” 

“[T]his might suggest,” they continue, “that either the caliber of education has decreased across this study’s sample and/or that there has been a shift in the perceived value of certain cognitive skills.”

Campus Reform contacted the authors of the study for comment and will update this article accordingly.