The Flynn Effect: Why IQ Scores Are Rising Across Generations

The Silent Evolution

If you were to take an average person from the year 1900 and transport them to today, they would score roughly 70 on a modern IQ test. By today’s standards, that is on the border of intellectual disability. Conversely, if you took an average person from today and sent them back to 1900, they would score around 130, placing them in the “Gifted” category.

Does this mean our great-grandparents were mentally impaired? Does it mean we are all geniuses? This phenomenon is known as the Flynn Effect, named after political scientist James Flynn, who discovered that raw IQ scores have been rising massively—about 3 points per decade—throughout the 20th century.

This finding shook the foundations of psychology. It suggested that human intelligence, long thought to be a static genetic trait, was actually moving at a velocity that evolution could not explain. In this article, we dismantle the causes, the misconceptions, and the potentially darker future of this global trend.

The Discovery: Unlocking the Archives

In the 1980s, James Flynn began looking at old military IQ manuals. He noticed a strange pattern: every time an IQ test was “renormed” (updated to set the average back to 100), the test makers had to make the questions harder.

If Americans in 1930 took a test from 1950, they scored lower. If they took a test from 1910, they scored higher. The bar was constantly being raised. The gains were not uniform, however.

• Vocabulary and Math: Small gains. These rely on learned knowledge (Crystallized Intelligence).
• Abstract Reasoning: Massive gains. Tests like Raven’s Progressive Matrices, which measure fluid reasoning and pattern recognition, saw the biggest spikes.

We weren’t getting better at knowing facts; we were getting better at thinking abstractly.

Why Are We “Smarter”?

Scientists have debated the drivers of the Flynn Effect for decades. Most agree that it is not a result of biological evolution—genes don’t change that fast. It is an environmental revolution.

1. The “Scientific Spectacles”

Flynn argued that our ancestors wore “utilitarian spectacles.” They cared about the concrete world: how to farm, how to fix a tool, how to hunt. Modern humans wear “scientific spectacles.” We are trained from birth to classify the world into abstract categories.

• 1900 Mindset: “A dog and a rabbit are similar because you use dogs to hunt rabbits.” (Functional relationship).
• 2020 Mindset: “A dog and a rabbit are similar because they are both mammals.” (Taxonomic/Abstract relationship). IQ tests heavily favor the latter. We have shifted from a concrete way of thinking to a hypothetical one.

2. The Visual & Cognitive Complexity of Environment

Our world is saturated with symbols. Maps, subway charts, computer interfaces, video games—we are constantly decoding abstract visual information. This “cognitive stimulation” acts like a 24/7 gym for the brain. A child playing a complex video game is solving hundreds of spatial and logic puzzles per hour. This constant training boosts Fluid Intelligence specifically.

3. Nutrition and Health

The brain is an energy-hog organ (consuming 20% of calories). In the early 20th century, malnutrition and infectious diseases were rampant.

• The Iodine Factor: The introduction of iodized salt is estimated to have raised global IQ by over 10 points by preventing cretinism and cognitive stunting.
• Lead Removal: The removal of lead from gasoline and paint in the late 20th century led to a measurable jump in cognitive scores in children.

4. Education as a Norm

Universal secondary education means that almost everyone spends their first 18 years doing exactly what IQ tests measure: solving problems, using logic, and thinking hypothetically. We have professionalized the act of test-taking.

The Paradox: Smarter Scores, Same Brains?

It is important to distinguish between “IQ Scores” and “Intelligence.” James Flynn often used the analogy of a shooter. If we all started practicing shooting hoops every day, our “shooting percentage” would skyrocket compared to 100 years ago. But that doesn’t mean we have evolved into giants; we just got better at that specific skill.

Similarly, we have become experts at the specific type of abstract logic that IQ tests value. We are better at manipulating symbols, but are we wiser? Are we more creative? Not necessarily. We have simply adapted to the demands of a modern, technological society.

The Reversal: Is the Party Over?

In the last 20 years, a new and concerning trend has emerged: The Negative Flynn Effect. Data from Norway, Denmark, Finland, and the UK suggests that the rise in IQ scores stopped in the mid-1990s and has actually begun to decline (by about 0.2 points per year).

Why the Reversal?

1. The Saturation Point: We may have maxed out the benefits of nutrition and education. Once everyone is well-fed and goes to school, you can’t get any more “boost” from those factors.
2. The Digital Shift: Some cognitive scientists argue that the smartphone era is degrading our attention spans and our ability to perform deep, sustained reading—skills that correlate with high g-factor. We are trading depth for speed.
3. Dysgenic Fertility: A controversial theory suggests that because higher-IQ individuals are having fewer children (and having them later in life), the genetic potential for intelligence in the population is slowly decreasing.

Conclusion: The Flexible Mind

The Flynn Effect teaches us the most important lesson in psychology: Intelligence is malleable. The human mind is not a fixed hard drive; it is an adaptive sponge that soaks up the complexity of its environment. We built a complex world, and our brains grew to match it.

As we move into the age of Artificial Intelligence, the definition of “smart” will likely shift again. Perhaps the next “Flynn Effect” won’t be about logic puzzles, but about our ability to synthesize information, collaborate with machines, and maintain our humanity in a digital world.

To understand where we are going, we must understand where we came from. Explore the History of IQ to see how our definition of genius has evolved over time.

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Frequently Asked Questions (FAQ)

Are we really smarter than our ancestors?

In terms of abstract logic, yes. We can solve problems involving hypothetical scenarios much better. However, our ancestors likely possessed superior practical intelligence, memory for oral traditions, and survival skills that we have lost. It is a trade-off.

Is the Flynn Effect happening everywhere?

It has happened in every country that has industrialized. Developing nations like Kenya and Sudan are currently experiencing massive Flynn Effects as their nutrition and education systems improve, mirroring the gains the West saw in the 1950s.

Why is the effect reversing now?

It is likely a combination of reaching the biological ceiling (we are as tall and smart as our current genes allow) and a shift in our environment. The digital age may be training us for “rapid switching” rather than the deep, linear logic required for IQ tests.

Does the Flynn Effect affect genius-level IQs?

Interestingly, the gains have been concentrated in the lower and middle parts of the distribution. We have raised the “floor” much more than the “ceiling.” The number of profound geniuses (160+ IQ) hasn’t increased at the same rate as the number of people with average IQs.

Can we keep getting smarter?

Biologically, probably not without genetic engineering. Environmental improvements have diminishing returns. The next leap in human intelligence will likely come from augmentation—integration with AI or direct neural interfaces—rather than better schools or food.