Are children getting smarter? IQ and the Flynn effect

Blog post published 16 October 2026

If your grandparents had sat a modern IQ test at their age, scored against today’s norms, their average would land well below 100. That doesn’t mean they were less capable. It’s one of psychology’s most intriguing findings: the Flynn effect.

How an IQ score works

An IQ score isn’t a raw mark out of a total. It shows how a person performed compared with a large reference group of people the same age. Most modern tests are scaled so the average is 100, with scores spreading evenly either side in a bell curve.

Because every score is relative, an IQ result is only as current as the group it’s compared against. That’s where the story gets interesting.

The Flynn effect

In the 1980s, New Zealand-based researcher James Flynn showed that people kept answering more IQ test items correctly with each passing generation. Across many countries, average scores rose by roughly three points per decade through much of the twentieth century.

The gains were biggest on tests of abstract, fluid reasoning, such as pattern and matrix puzzles. They were much smaller on vocabulary and general knowledge. Because tests are regularly re-normed to keep the average at 100, the rise stayed hidden in everyday scores for decades.

Why did scores rise?

Genes don’t change that quickly, so researchers look to the environment. Likely contributors include better nutrition and health, more years of schooling, smaller families, and daily lives full of abstract thinking: classifying, hypothesising and solving unfamiliar problems. Flynn himself argued that we didn’t simply become “smarter”, but became more fluent at the kind of reasoning IQ tests reward.

And now the plot twist

Since the 1990s, the rise has slowed, stalled or even reversed in some developed countries, including Norway, Denmark and Finland. Studies comparing brothers within the same families point to environmental causes here too, though researchers are still debating which ones.

What this means for your child

The lesson for parents is encouraging. Reasoning ability isn’t fixed at birth; it responds to the environment a child grows up in. Rich, challenging learning, the kind that asks children to spot patterns, reason through unfamiliar problems and explain their thinking, makes a real difference.

That’s the thinking behind our enrichment programs. Galileo’s Gang, Maths Talent and Advanced English are designed to stretch bright minds with problems that don’t have obvious answers. For more on nurturing high-potential learners, read our Guide to Supporting the Gifted Child.