Glossary
Negative Flynn effect
Definition
The negative Flynn effect is a reported decline in average measured IQ among people born in recent decades, reversing the long rise seen through the 20th century. The best-known evidence comes from Norwegian conscript data for cohorts born after about 1975.
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Background: the Flynn effect
Through the 20th century, average measured IQ rose. A 2015 meta-analysis of 271 samples, about 4 million people in 31 countries, estimated gains of about 2.8 points per decade and found those gains slowing in recent decades (Pietschnig & Voracek, 2015). The term “negative Flynn effect” names a reversal of that trend.
The evidence
Bratsberg and Rogeberg reported a decline in Norwegian conscript test data for cohorts born after about 1975 (Bratsberg & Rogeberg, 2018). Conscript data is useful because it covers nearly every young man in a cohort, not a self-selected group.
Why it matters for IQ scores
Whether averages rise or fall, a test scored against old norms drifts. If the average shifts, a score of 100 on an old table no longer means exactly average today. That is why the standardization sample gets renewed with new editions.
Common confusions
A change in averages across generations says nothing about any one person. It is also easy to overread: the causes are still debated. One firm result: a Norwegian study of brothers found the rise, the turning point and the decline all within families, which points to environmental causes rather than changes in who has children (Bratsberg & Rogeberg, 2018). Read the Flynn effect, the entry on meta-analysis, and why IQ tests are renormed.
Try one · Spatial Reasoning
Which option is the same shape, only rotated?
Tap the option you think is right, or show the answer.
Show the answer
Option 1 is the original figure turned a half turn.
How to solve it
- Pick a landmark: the marked cell or the end of the longest arm.
- Turn the figure in your head and watch where that landmark goes, and which side the other cells end up on.
- Turning the figure a half turn gives option 1.
- Each of the other options is a mirror image: flipping it over would match, but no turn does.
That was 1 puzzle. The full test has 25.
Sources
- Bratsberg, B., & Rogeberg, O. (2018). Proceedings of the National Academy of Sciences, 115(26), 6674-6678. doi.org/10.1073/pnas.1718793115
- Pietschnig, J., & Voracek, M. (2015). One century of global IQ gains. Perspectives on Psychological Science, 10(3), 282-306. doi.org/10.1177/1745691615577701