Average IQ of Gen Z: Is a Generation Getting Smarter?

The Flynn effect: a century of rising scores

When you do hold the yardstick fixed, a striking pattern appears. Named after political scientist James Flynn, who documented it systematically in the 1980s, the Flynn effect describes a long, steady rise in raw IQ performance across the developed world through the 20th century. Flynn's early analysis found roughly a 13.8-point gain in the United States between 1932 and 1978 — about 0.3 points per year, or 3 points per decade.

The gains were largest on the most abstract, "fluid" reasoning tasks and smaller on knowledge-heavy questions. Proposed drivers include better nutrition, longer and better schooling, smaller families, healthier early childhood, and a culture that trains us to think in the abstract categories that IQ tests reward. This is why test publishers re-standardize their tests every so often — a set of norms drifts out of date at roughly 3 points per decade, so an un-revised test slowly gets "too easy."

The reversal: scores falling since the 1990s

Here is where Gen Z enters the story. In several developed countries, the century-long climb appears to have peaked and turned down for cohorts born from the mid-1970s onward — the parents of Gen Z, and Gen Z itself.

The clearest evidence comes from Norway. Bratsberg and Rogeberg (2018) analyzed cognitive test scores from more than 730,000 male military conscripts born between 1962 and 1991. Scores peaked for the 1975 birth cohort and then declined by roughly 0.2 points per year. Crucially, the study included brothers, letting the authors compare siblings born in different years. The decline showed up within families — younger brothers scored lower than their older brothers — which rules out the usual scapegoats of genetic selection or immigration and points squarely at something in the shared environment. Their blunt conclusion: the Flynn effect and its reversal are both environmentally caused.

Norway is not alone. Similar stalls or declines on large-sample or conscription data have been reported in Denmark, Finland, France, and the United Kingdom since roughly the mid-1990s. In the United States, a 2023 study led by Elizabeth Dworak at Northwestern University examined hundreds of thousands of adults tested between 2006 and 2018 and found scores dropping in verbal reasoning, matrix reasoning, and number series — with the notable exception of 3D spatial rotation, which rose. The pattern held across age, education, and gender.

What might be driving it — and what we don't know

It is tempting to blame smartphones, and screen time is one of the hypotheses on the table. But honest scientists are cautious here, because the reversal began for cohorts born in the 1970s — long before the iPhone. The leading candidates are broad and hard to disentangle: changes in how schools teach and test, shifts in reading habits away from long-form text, changes in the nature of work and leisure, and altered patterns of attention. Some researchers also note that as environmental conditions in rich countries hit a ceiling, the "easy" gains from better nutrition and schooling that fueled the original Flynn effect simply ran out.

Two caveats matter a lot. First, the reversal is not universal — many emerging economies are still posting Flynn-style gains as their environmental floors keep rising. Second, and most important, a change in test scores is not the same as a change in intelligence. As Dworak herself put it, a difference in scores "doesn't mean their mental ability is lower or higher" — it can reflect what a particular test happens to measure and what a particular generation is practiced at. Gen Z has grown up fluent in tools and skills that no standardized IQ battery was designed to capture.

The honest note on "kids these days"

Every generation has accused the next of being distracted, coddled, or dim; the complaint is as old as writing itself. The data give that instinct no comfort. The measured declines are small — a fraction of a point per year — and they sit inside a century of gains so large that a bright Gen Z teenager scored against 1930s norms would look like a genius. The reversal is a real and worth-studying signal about environments, not a verdict on a generation's worth or potential.

So if you are Gen Z wondering where you stand, the generational average is a distraction. Your IQ score tells you how you compare to your own peers today, not to your grandparents. If you are curious about that personal number, a well-designed test scored against modern norms will tell you far more than any headline about a generation.

Frequently asked questions

Q: What is the average IQ of Gen Z?

A: 100, by design. IQ tests are age-normed so the average of each generation is set to 100 with a standard deviation of 15. Comparing generations by this normed average is meaningless; the interesting comparisons come from scoring different birth cohorts against the same fixed yardstick.

Q: Is Gen Z smarter than previous generations?

A: Not by raw test scores in several developed countries. After a century of rising scores (the Flynn effect), large studies in Norway, the US, and parts of Europe show scores peaking around the mid-1970s birth cohort and slowly declining since — a fraction of a point per year, and only on certain measures.

Q: What is the reverse Flynn effect?

A: The recent stalling or decline of the century-long rise in IQ scores. Bratsberg and Rogeberg (2018) found Norwegian scores fell about 0.2 points per year after the 1975 cohort, and the drop appeared within families — evidence it is driven by environment, not genes or migration.

Q: Does a lower score mean Gen Z is less intelligent?

A: No. A change in test scores is not the same as a change in intelligence. Researchers stress the shifts likely reflect what tests measure and what each generation is practiced at, and some skills — such as 3D spatial reasoning in the US data — have actually risen.

Q: Why do old IQ tests give higher scores?

A: Because their norms are out of date. Raw performance historically rose about 3 points per decade, so a test normed decades ago has a "too easy" yardstick. Test publishers re-standardize periodically to keep the average anchored at 100.

References

• Bratsberg, B., & Rogeberg, O. (2018). Flynn effect and its reversal are both environmentally caused. Proceedings of the National Academy of Sciences, 115(26), 6674–6678.
• Dworak, E. M., Revelle, W., & Condon, D. M. (2023). Looking for Flynn effects in a recent online U.S. adult sample: Examining shifts within the SAPA Project. Intelligence (summary via Northwestern University / ScienceDaily).
• Trahan, L., Stuebing, K. K., Fletcher, J. M., & Hiscock, M. (2014). The Flynn effect: A meta-analysis. Psychological Bulletin, 140(5), 1332–1360.
• Flynn effect — Wikipedia (overview and country-by-country summary).

Last updated: July 13, 2026