Does IQ Increase Over Generations? | The Flynn Effect

IQ raw scores rose across many 20th-century cohorts, but new test norms reset averages and recent trends vary by country.

IQ can rise across generations in one sense and stay fixed in another. The split comes from how tests are scored. When people from a newer cohort take an older test, they often score higher than the group used to set that old test’s scale. Yet when a test publisher updates norms, the average score is set back to 100 for the new age group.

That means your grandparent’s test, your parent’s test, and your test may not share the same yardstick. A score of 100 is not a timeless amount of ability. It means average performance against people of the same age in the norm sample for that test version.

The rise in raw scores is called the Flynn effect. It doesn’t prove each person is born smarter than the last. It says that groups have become better at the kinds of reasoning, pattern finding, and test tasks that IQ tests measure.

The Careful Answer On Generational IQ Gains

The clearest answer is: raw IQ test performance rose across much of the last century, often by about 2 to 3 points per decade in many richer nations. Across 30 years, that can look like a large jump. But published IQ scores hide that rise because tests are renormed.

Renorming is the reset. Test makers give the revised test to a fresh sample, then set the average to 100. If they didn’t, people tested on old norms could appear to have inflated scores, not because the person is rare, but because the ruler is old.

This is why the question can sound odd. A population can gain raw points while the average reported IQ remains 100. Both statements can be true at the same time.

Why IQ Scores Rose Across Generations In Older Tests

Researchers still debate exact causes, but several changes line up with the pattern. Schools reached more children. Abstract symbols became part of daily life. More jobs asked workers to sort, compare, classify, and solve paper problems. Health and childhood nutrition improved in many places. Families also had smaller sizes, so adults could spend more time per child.

IQ tests reward a certain kind of mental habit. Matrix puzzles, analogies, pattern series, and category sorting all favor people used to dealing with symbols detached from daily objects. A person raised with more years of schooling and more printed material may handle those tasks with less strain.

The largest gains often show up on fluid reasoning tasks. Those tasks ask for pattern solving without relying much on memorized facts. Vocabulary and general knowledge gains tend to be smaller, which hints that the rise is not one simple jump in every kind of ability.

What Changed From One Cohort To The Next

The APA’s Flynn effect definition describes a gradual rise in raw test scores across many groups. A century-scale Flynn effect review pooled samples from many countries and found gains across a long span, with size differing by ability type and place.

Still, IQ gains are not a badge pinned on every person in a generation. They are group averages. A newer cohort can score higher on older tests while many individuals in it score below many individuals from older cohorts.

It helps to split broad social change from test-taking craft. Some drivers may raise reasoning skill; others mainly reduce confusion, fatigue, or surprise when the booklet starts and the clock begins on page one.

Driver	How It Could Lift Raw Scores	Where The Effect Shows Most
Longer schooling	More practice with symbols, categories, and timed tasks	Matrix puzzles, number series, word reasoning
Better childhood health	Fewer learning setbacks tied to illness or undernutrition	Attention, processing speed, school readiness
Smaller family size	More adult time and reading per child	Vocabulary, rule learning, task persistence
More abstract work	Daily tasks train sorting, planning, and rule use	Fluid reasoning and problem solving
Urban life	More signs, schedules, forms, maps, and systems to read	Symbol use and mental flexibility
Test familiarity	Less surprise when facing multiple-choice or timed formats	Speed, confidence, strategy
Mass media and games	More pattern, spatial, and rule-based tasks in daily leisure	Visual reasoning and quick decisions
Lower lead exposure	Less harm to attention and learning in childhood	Broad school and reasoning outcomes

Why Raw Gains Do Not Mean Everyone Became Smarter

The tricky part is that IQ is a ranking score. A reported IQ places a person against age peers from a norm group. If the norm group changes, the same raw answers can produce a different score.

Think of a running race where the course changes each decade. If shoes, training, diet, and track surfaces improve, average race times may drop. Yet medals are still handed out by who ran fastest in that race, not by comparing every runner to athletes from 70 years ago.

That is how IQ norms work. They keep the average score near 100 so a score tells you where a person stands among age peers. This makes tests useful for school placement, clinical screening, and research, but it also means a modern IQ number cannot be read as a direct comparison with a 1950 score.

Modern Norms Reset The Yardstick

Old norms can make a score look higher. New norms can make the same raw performance look lower. For that reason, clinicians care about test edition, norm year, age group, and test type before reading a score.

The Flynn effect also varies by subtest. A rise in matrix reasoning does not automatically mean the same rise in verbal knowledge, working memory, or processing speed. One number can hide a mixed pattern underneath.

Where The Rise Has Slowed Or Reversed

The answer is no longer a plain upward line. In several wealthy countries, gains have slowed, flattened, or turned downward on some tests. Recent work using German student samples from 2012 to 2022 found that patterns can differ across abilities, which makes broad claims risky.

This doesn’t mean society is getting duller by the year. It means test scores can move for reasons tied to schooling, reading habits, screen habits, migration patterns, test content, health, and how well a test fits the skills people practice.

Claim	Better Reading	Reader Takeaway
“Each generation has a higher IQ.”	Raw scores often rose on older tests, but norms reset reported IQ.	Ask whether the claim means raw scores or normed scores.
“The Flynn effect proves people are smarter.”	It proves gains on certain test tasks, not every kind of ability.	Check which subtests changed.
“IQ is now falling everywhere.”	Some countries and tests show declines; others show mixed patterns.	Place and test type matter.
“An old score and a new score match.”	They may use different norms and test editions.	Compare only with care.

How To Read Any Claim About Rising IQ

When you see a headline about IQ rising or falling, slow down and ask what was measured. A solid claim should name the test, the country, the birth years, the age group, and whether scores were raw or normed.

• Check whether the test was the same across cohorts.
• Ask whether the sample was broad or narrow.
• Separate raw test points from reported IQ points.
• Watch for claims that treat one subtest as total intelligence.
• Be wary when a headline turns a group trend into a claim about every person.

The strongest reading is also the most useful one: IQ tests capture a set of reasoning tasks under set conditions. Those tasks can improve across cohorts when daily life gives people more practice with the same mental moves.

The Practical Answer For Readers

So, does the rise matter? Yes, but only when read the right way. The Flynn effect changed how test scores are interpreted, why old norms expire, and why a person’s score must be tied to the test edition used.

For everyday readers, the take-home point is simple: generations have often become better at IQ-style tasks, yet IQ scores are built to compare people with current age peers. A score of 100 still means average for the test’s norm group, not average across all humans who ever took an intelligence test.

If you want the cleanest answer, say this: generational raw scores rose across much of the 20th century, recent patterns are mixed, and modern IQ scores stay centered at 100 because the scale is reset. That keeps the number useful, but it also stops us from treating IQ as a fixed ruler across time.