Across nearly seven decades of the 20th century, IQ test scores climbed upward, a trend known as the “Flynn effect.”

A Norwegian study published in the American journal Proceedings of the Natural Academy of Sciences on Tuesday has now revealed what many have already anticipated: Humans are losing IQ points.

Research drawing on military conscription data from Norwegian births spanning the years 1962 to 1991 — a massive sample size of 730,000 cases — shows what the authors Bernt Bratsberg and Ole Rogeberg describe as “the Flynn effect, its turning point, and subsequent decline.”

The effect is named after intelligence researcher James Flynn, whose studies showed an average increase of three IQ points per decade throughout the 20th century.

In 2009, Flynn released a study on British teenagers in particular, and noted a decline in IQ test scores. It was chalked up then to “something screwy among British teenagers,” as Flynn told The Telegraph.

“While we have enriched the cognitive environment of children before their teenage years, the cognitive environment of the teenagers has not been enriched,” Flynn surmised at the time.

The recent Norwegian study is “the first authoritative study of the phenomenon,” the British publication The Times reported.

It’s worrying, to say the least: The Norwegian study shows a strong reversal of seven IQ points per decade since 1975. By using birth cohorts (a group of people born at about the same time) and first-born sons, the scientists controlled for genetic variation and environmental factors (females were not included in the study).

Various hypotheses have been floated to explain the decline in IQ scores. The decrease has accompanied an explosion in technology, along with widespread changes in teaching curricula in the Western world.

“Scientists say that the deterioration could be down to changes in the way maths and languages are taught, or to a shift from reading books to spending time on television and computers,” The Times noted.

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Stuart Ritchie, a psychologist from the University of Edinburgh who did not participate in the research, shared his reaction to it with The Times.

“This is the most convincing evidence yet of a reversal of the Flynn effect,” Ritchie said. “If you assume their model is correct, the results are impressive, and pretty worrying.”

Many others have questioned the validity of IQ scores when it comes to testing for various types of intelligence, including “fluid intelligence.”

“Crystallized intelligence is stuff you have been taught and trained in, and fluid intelligence is your ability to see new patterns and use logic to solve novel problems,” Rogeberg, the research economist who co-authored the study, explained to The Times.

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Technology indeed may be changing the way our brains process information; when there is so much knowledge stored on digital memory, instead of in our own, people may adapt by switching to different forms of pattern recognition and problem computation.

In other words, the way people problem-solve, or have their problems solved for them, appears to be changing. Peter Dockrill of the publication Science Alert also gave his conjecture about possible causal factors.

“It suggests changes in lifestyle could be what’s behind these lower IQs, perhaps due to the way children are educated, the way they’re brought up, and the things they spend time doing more and less (the types of play they engage in, whether they read books, and so on),” Dockrill wrote.

Educators have warned about declining standards and the ill effects of progressive education for decades.

Karl Shapiro, the renowned poet-professor, told the California Library Association as far back as 1970 he was concerned for students.

“What is really distressing is that this generation cannot and does not read,” he said then, as Reason magazine reported.

“I am speaking of university students in what are supposed to be our best universities,” Shapiro continued. “Their illiteracy is staggering … We are experiencing a literary breakdown which is unlike anything I know of in the history of letters.”

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Allan Bloom, the late professor and author of “The Closing of the American Mind,” a sweeping 1987 account that remains one of the most popularized harbingers of intellectual decline, gave his withering critique of the U.S. education system in his book.

“Openness used to be the virtue that permitted us to seek the good by using reason. It now means accepting everything and denying reason’s power,” Bloom wrote.

Are today’s schoolchildren being raised to be so open-minded that their ability to reason has fallen away?

As others note about the study, “Researchers also found some differences between family groups, suggesting that some of the decline might be due to environmental factors,” as MedicalXpress noted in its write-up. “They also suggest that lifestyle changes could account for some of the decline as well, such as changes in the education system and children reading less and playing video games more.”

Kyle Becker is a content writer and producer with LifeZette. Follow him on Twitter