ХХ зууны турш тасралтгүй өсөж байсан хүний IQ буюу оюун ухааны коэффициент сүүлийн жилүүдэд буурах хандлагатай болсныг шинэ судалгаагаар илрүүлжээ.
Францад боловсруулж, АНУ-д нэвтрүүлсэн IQ-гийн тест нь 1930-аад оноос эхлэн үеийн үед бага зэргээр өсөх хандлага ажиглагдаж байв. Судлаач Жеймс Флинний нэрээр “Флинний эффект” хэмээн нэрлэгдсэн энэхүү үзэгдлийн хүрээнд дундаж оюун ухааны оноо арван жил тутамд гурван оноогоор нэмэгдэж байсан юм. Энэхүү өсөлт нь илүү сайн тэжээл, боловсрол, эрүүл орчинтой холбоотой хэмээн таамаглаж байв.
Гэвч зарим оронд стандарт тестаар хэмжихэд хүний оюун ухааны түвшин буурч эхэлснийг мэдээлэх болжээ. Энэхүү зүй тогтол АНУ-д мөн ажиглагдаж байгаа эсэхийг судлахаар Northwestern University-гийн судлаач Элизабет Дворак болон түүний баг 2006-2018 оны хооронд цуглуулсан бараг 400,000 насанд хүрэгчдийн тестийн үр дүнд дүн шинжилгээ хийсэн байна. Тэд 18-90 насны оролцогчдын хийсэн олон улсын танин мэдэхүйн чадварын нээлттэй тестүүдийн үр дүнг матриц дүгнэлт, үгэн болон тоон цуврал, ярианы зэрэг хэд хэдэн чиглэлээр тусгайлан судлав.
Судалгааны дүнгээр Флинний эффектийн эсрэг буюу IQ оноо буурсан үзүүлэлт илэрсэн нь судлаачдын хувьд ч гэнэтийн зүйл болжээ. Энэхүү бууралт нь хүйс, боловсролын түвшин болон насны бүлгүүдэд ерөнхийдөө ажиглагдсан бөгөөд ялангуяа 18-22 насны залуучууд болон боловсролын түвшин доогуур оролцогчдын дунд хамгийн өндөр байв. Абстракт болон логик сэтгэлгээг хэмжих матриц болон цуврал даалгаврын оноо буурсан бол ярианы чадвар харьцангуй тогтвортой байжээ.
Харин гурван хэмжээст орон зайд объектыг дүрслэн эргүүлэх чадварын оноо өссөн болохыг судлаачид онцолжээ. Энэхүү өөрчлөлт нь ухаалаг утас, интернэт хэрэглээ нэмэгдэхтэй зэрэгцэн гарсан бөгөөд мэдээлэл боловсруулах болон сэтгэлгээний хэв маяг өөрчлөгдөж байгаатай холбоотой байж магадгүй гэж үзэж байна. Судалгааны үр дүн “Intelligence” сэтгүүлд нийтлэгджээ.
Дэлгэрэнгүйг эх сурвалжаас харах
↓Эх сурвалжийг нээх ↓
Just over a hundred years ago, the Binet IQ test was developed in France and soon after, brought to the United States, where it was given to public school kids, physicians, and immigrants at Ellis Island.
From the 1930s, IQ scores seemed to be inching up – with each new generation scoring a little higher than the last. Throughout the 20th century, average intelligence scores rose by about 3 points a decade, even when researchers used different tests and metrics.
Those small gains added up, meaning that someone’s genius-level great-grandparents might only be considered a bit smart by their own generation.
This increase was called the “Flynn Effect” after the educator James Flynn, who published about it in 1984.
What caused it?
Hypotheses ranged from population-wide changes like better nutrition, fewer siblings, earlier education, more complex environments, and genetic effects (unlikely, since genes take longer than a few generations to change).
Increasing IQ was seen as a positive thing, since it’s correlated with higher educational attainment, better jobs, and even a longer, healthier life.
It was expected that this increase would keep going, even if at a slower pace, as humanity advanced.
And then people started getting ‘dumber’.
Or at least, their scores on an IQ test dropped. In Europe, several countries reported declining intelligence as determined by standardized tests.
To find out whether the same pattern is emerging in the US, social scientist Elizabeth Dworak made that question the topic of her master’s thesis at Northwestern University. She and her colleagues analyzed cognitive test scores from nearly 400,000 American adults collected between 2006 and 2018.
The team drew on data from the Synthetic Aperture Personality Assessment (SAPA) Project, an online research platform that has gathered responses from more than a million participants.
Their analysis focused on 394,378 people aged 18 to 90 who completed questions from the International Cognitive Ability Resource (ICAR), an open-source intelligence test.
Rather than just looking at a single overall score, Dworak and colleagues examined several cognitive areas separately.
These included matrix reasoning, which measures abstract pattern recognition and problem-solving; letter and number series, which assesses logical reasoning through sequences; verbal reasoning, which draws on vocabulary and general knowledge; and three-dimensional rotation, a test of mental spatial visualization.
The researchers also calculated overall composite scores across the different tasks.
Across the 13-year study period, they found evidence consistent with a reverse Flynn effect.
Even Dworak was surprised.
“I spent weeks going back through all the code,” she told New York magazine.
“I thought I’d messed something up and would have to delay submitting. But then I showed my adviser, and he said, ‘Nope, your math is right.'”
Composite cognitive scores declined over time, with the trend appearing across age groups, education levels, and in both men and women. The steepest declines were seen among adults aged 18 to 22 and among participants with lower levels of education.
But there was significant variability in the decline depending on subject area. Matrix reasoning and letter-and-number series scores generally declined alongside the overall composite scores, suggesting reduced performance in abstract and logical reasoning tasks.
Verbal reasoning showed comparatively little change, with declines too small to meet the researchers’ threshold for a meaningful reverse Flynn effect.
One domain stood out as moving in the opposite direction.
Scores on the three-dimensional rotation task, which measures the ability to mentally manipulate objects in space, improved over the study period. (A theory is that video games might be driving this part of the trend.)
This increase was seen across much of the adult age range, suggesting that while some forms of reasoning may be weakening over time, spatial abilities appear to be improving.
Other tests show similar trends: the ACT, a test used as an alternative to the SAT for college admissions, has seen a steady decrease in average scores over the last decade, and the SAT has also seen declines.
This decline started well before generative artificial intelligence was commonly available as a tool (or cheating mechanism).
The downward intelligence trend also began prior to the pandemic, so neither lockdowns nor COVID itself can be blamed. But the late 2000s is when smartphone use started to rise: Could that be the culprit?
James Marriott, a columnist for the Times of London, thinks so. He argues that the switch from reading print to reading on smartphones has led to the degradation of intellect.
“Print requires us to make a logical case for a subject,” Marriott said in a recent UnHerd podcast episode (above).
“A really significant feature of books is that if you make a case in print, you have to make it logically add up.
“You can’t just assert things in the way you can on TikTok or on YouTube… print privileges a whole way of thinking and a whole way of processing the world that is logical, that is more rational, that is more dense information, that is more intellectually challenging.”
Dworzak’s study can’t explain why these trends occurred.
Because the research used repeated cross-sectional data rather than following the same individuals over time, it identifies population-level changes but isn’t able to determine their underlying causes.
Nonetheless, the findings suggest that recent changes in cognitive performance are complex, affecting different mental abilities in different ways rather than reflecting a simple rise or fall in intelligence.
Related: It’s Not Just You: Scientists Say Modern Life Is Pushing The Human Mind Beyond Its Limits
What we do know is that our intelligence is probably changing – but how far-reaching and important those effects are is unknown.
Maybe gaining strength in some areas and getting weaker in others is perfectly logical in a changing, dynamic culture that characterizes the one we are living in right now.
The research has been published in the journal Intelligence.
This article was fact-checked by Rachel Garner and edited by Rebecca Dyer. While we pride ourselves on our process, we are only human. If you spot a mistake, please let us know.
