For nearly a century, IQ scores climbed steadily upward—each generation outperforming the last on standardized intelligence tests. But that trend has reversed. New research confirms what scientists have been quietly tracking: average IQ scores are now declining in some populations, marking the first sustained drop since testing began. The shift is small but measurable, and it's raising questions about how modern life is reshaping the way we think.

What the Research Actually Shows

The decline isn't universal, but it's real.

A 2018 study published in the Proceedings of the National Academy of Sciences analyzed intelligence test data from Norwegian military conscripts born between 1962 and 1991. Researchers Bernt Bratsberg and Ole Rogeberg found that IQ scores rose steadily through the mid-20th century, then began to fall—dropping by an average of about 7 points per generation in some cohorts.

In the United States, a separate 2023 study published in the journal Intelligence examined online test data from 2006 to 2018. Researchers Elizabeth Dworak, William Revelle, and David Condon found declines in specific cognitive domains—particularly abstract reasoning and verbal comprehension—among younger participants.

These studies don't suggest people are becoming less intelligent overall. They show that certain measurable cognitive skills are shifting.

Understanding the Flynn Effect Reversal

For most of the 20th century, IQ scores rose by about 2 to 3 points per decade.

This pattern became known as the Flynn Effect, named after researcher James Flynn who documented it in the 1980s. The rise was attributed to better nutrition, expanded education, smaller family sizes, and increased cognitive stimulation from urbanization and technology.

But starting in the 1990s, that trend began to plateau in some developed nations. By the early 2000s, it reversed in others. Norway, Denmark, Finland, France, and the Netherlands all reported declines. The United States showed mixed results—some age groups improved, others declined.

What changed? The Bratsberg and Rogeberg study concluded that the reversal is driven by environmental factors, not genetics. IQ is shaped by both biology and experience—and something about modern environments appears to be altering the cognitive skills we develop.

Why Scores Are Dropping

Screen Time and Cognitive Function

Digital devices have fundamentally changed how we process information.

Excessive screen time—especially passive consumption like scrolling social media or watching short videos—reduces opportunities for deep focus, sustained attention, and complex problem-solving. These are the exact skills measured by abstract reasoning tests.

Consider this: reading a book requires your brain to construct mental images, follow narrative threads, and hold information in working memory. Watching a TikTok video does most of that work for you. Over time, the brain adapts to the demands placed on it—and if those demands are lower, certain cognitive abilities weaken.

Educational System Changes

Modern education increasingly emphasizes standardized testing and rote memorization over creative problem-solving and critical thinking. Students spend more time preparing for specific test formats and less time exploring open-ended questions or hands-on learning.

This shift may improve test-taking skills but doesn't necessarily build the kind of flexible, abstract reasoning that IQ tests measure. It's the difference between learning to follow a recipe and learning to cook.

Environmental and Nutritional Factors

Exposure to environmental toxins—lead, air pollution, endocrine disruptors—has been linked to cognitive impairment, particularly in early childhood. While lead exposure has decreased in many countries, other pollutants remain widespread.

Nutrition also plays a role. Diets high in processed foods and low in essential nutrients can affect brain development and function. Sleep deprivation, increasingly common among adolescents, further impairs cognitive performance.

What This Means for Society

Declining IQ scores don't mean people are becoming less capable.

Intelligence is multifaceted—IQ tests measure specific skills like pattern recognition, verbal reasoning, and mathematical logic. They don't capture creativity, emotional intelligence, practical problem-solving, or the ability to navigate complex social environments.

Some researchers suggest that modern life may be developing different cognitive strengths—multitasking, visual processing, rapid information filtering—that traditional IQ tests don't measure. A teenager who can't solve a logic puzzle might excel at coordinating a team project online or troubleshooting a technical problem through trial and error.

Still, the decline in abstract reasoning and verbal comprehension raises concerns. These skills underpin innovation, scientific thinking, and the ability to evaluate complex information—all critical for a functioning democracy and a competitive workforce.

How to Reverse Cognitive Decline

IQ isn't fixed. It reflects both biology and environment—and environments can change.

Encourage deep reading. Books, long-form articles, and complex narratives build sustained attention and comprehension. Aim for material that challenges you—not just entertainment, but content that requires thought.

Practice critical thinking. Engage with problems that don't have obvious answers. Debate ideas, analyze arguments, question assumptions. Play strategy games like chess or Go. Solve puzzles that require logic and pattern recognition.

Limit passive screen time. Replace scrolling with activities that demand active engagement—writing, building, coding, drawing. Use technology as a tool for creation, not just consumption.

Prioritize hands-on learning. Physical activities that require planning and problem-solving—cooking, woodworking, gardening, repairing things—build cognitive skills in ways that passive learning doesn't.

Protect brain health. Get adequate sleep. Eat a diet rich in omega-3 fatty acids, antioxidants, and whole foods. Minimize exposure to environmental toxins. Exercise regularly—physical activity improves cognitive function across all age groups.

The reversal of the Flynn Effect is a signal, not a sentence. It tells us that the environments we've built are shaping our minds in ways we didn't anticipate. The question now is whether we'll adapt those environments—or let them continue to adapt us.