Yes, the Flynn effect is reversing in several countries. After nearly a century of steady IQ gains across generations, scores have begun declining in parts of Scandinavia, Western Europe, and the United States. The turnaround appears to have started with people born after the mid-1970s, and the pattern has grown clearer with each new decade of data.
What the Flynn Effect Is and Why It Matters
For most of the 20th century, each generation scored higher on standardized intelligence tests than the one before it. This trend, named after researcher James Flynn, amounted to roughly 3 IQ points per decade in many countries. The gains were massive over time: someone scoring average in 1950 would have scored well below average by 1900 standards. Improvements in nutrition, education, healthcare, and cognitive stimulation all likely contributed.
The reversal matters because IQ scores, whatever their limitations, correlate with outcomes that affect entire economies: educational attainment, workforce productivity, and the ability to navigate increasingly complex systems. A sustained decline would have implications that extend well beyond test scores.
Where Scores Are Falling
The strongest evidence for a reversal comes from Scandinavia. A large Norwegian study published in the Proceedings of the National Academy of Sciences tracked military conscription test scores and found a clear decline for men born after 1975. The drop averaged about 0.23 IQ points per year across the population. When researchers projected losses in Nordic countries after 1995 over a thirty-year window, the cumulative decline reached nearly 7 IQ points, essentially erasing two decades of earlier gains.
In the United States, a study using data from over 394,000 adults tested between 2006 and 2018 found declining scores in several key areas. Composite ability scores dropped across the board, and the pattern held regardless of age, education, or gender. Britain and Germany have reported similar downward trends, particularly on tests measuring spatial reasoning and certain forms of logical thinking.
Some Abilities Are Declining Faster Than Others
The reversal isn’t hitting all cognitive skills equally. In the U.S. study, the sharpest drops appeared in matrix reasoning (visual problem-solving and pattern recognition) and letter-and-number series (mathematical and sequential thinking). Verbal reasoning scores also declined, though at a slower rate that barely crossed the threshold researchers considered meaningful.
Interestingly, one area bucked the trend entirely. Scores on 3D rotation tasks, which measure spatial reasoning, actually increased from 2011 to 2018. This kind of uneven pattern suggests the reversal isn’t about people becoming broadly “less intelligent.” Something more specific is happening to particular cognitive skills, which points toward environmental and cultural explanations rather than any fundamental biological shift.
Environmental Causes, Not Genetic Ones
The Norwegian study offered one of the most important clues about what’s driving the decline. Researchers compared brothers raised in the same families and found that the younger brother often scored lower than the older one, even though they shared the same parents and household. This within-family pattern rules out changes in who is having children as the primary explanation. If genetics or demographic shifts were responsible, brothers from the same family would score similarly.
The within-family decline was smaller than the population-wide trend (about 0.08 IQ points per year versus 0.23), which means some of the broader decline does reflect changes in the composition of who’s being tested. But the fact that scores dropped even between siblings in the same home points squarely at environmental factors: changes in education, media consumption, cultural priorities, or other shared influences that shift over time.
Screen Time and Changing Cognitive Habits
One frequently discussed factor is the rise of digital media. A longitudinal study tracking children over about three years found that more frequent internet use was associated with a decline in verbal intelligence and reduced development of gray and white matter volume across multiple brain regions. These effects didn’t show up in a single snapshot but emerged over time, suggesting that habitual heavy internet use gradually reshapes how the brain develops during childhood and adolescence.
Other research has linked increased smartphone use to a less analytical cognitive style and lower performance on reasoning tasks. The mechanism likely isn’t that screens make people “dumber” in some permanent sense, but that time spent scrolling, watching short-form video, and skimming text displaces the kind of sustained, effortful thinking that builds the skills measured by IQ tests. Reading long-form material, solving novel problems, and engaging in complex conversation all exercise the cognitive muscles that standardized tests capture. If people do less of that, scores reflect it.
Socioeconomic Gaps Complicate the Picture
The reversal isn’t happening in a vacuum. Background research on intelligence and socioeconomic status shows that children from lower-income families start with scores about 6 IQ points below their higher-income peers at age 2. By age 16, that gap nearly triples to 15 to 17 points, depending on gender. This widening gap means that any population-level decline is likely felt more acutely at the lower end of the income spectrum, where children have fewer resources to buffer against whatever environmental changes are pulling scores down.
If the factors driving the reversal (reduced reading, increased screen time, shifts in educational emphasis) disproportionately affect lower-income households, the population-wide average could drop even while scores hold steady or rise among more affluent groups. The overall number masks very different experiences depending on circumstances.
How Large Is the Decline, Really?
Context matters here. The original Flynn effect produced gains of roughly 3 points per decade. The reversal in Norway shows losses of about 2 points per decade based on the population-wide estimate. Nordic countries collectively are tracking a loss of nearly 7 points projected over 30 years. These are meaningful numbers in population terms, but they don’t signal a dramatic collapse in human cognitive ability.
For any individual, a shift of a few IQ points is barely noticeable. The significance is statistical: across millions of people, small average shifts change the distribution of scores at the extremes. Fewer people land in the very high range, more cluster toward the middle. Over decades, that reshaping of the curve can influence the talent pool for fields that depend on exceptional analytical ability, and it can shift how many people struggle with cognitively demanding tasks in daily life.
The reversal also isn’t universal yet. Some developing countries are still experiencing classic Flynn effect gains as nutrition, education, and healthcare improve. The decline appears concentrated in wealthy, post-industrial nations where the original gains may have plateaued and new environmental pressures have taken hold. Whether the trend deepens, stabilizes, or eventually reverses again likely depends on how societies respond to the cultural and educational shifts already underway.