The Flynn effect describes a phenomenon in intelligence testing observed across much of the 20th century and beyond, where average IQ scores have increased by approximately three points per decade across many populations worldwide. 

Increases have been particularly pronounced in what we call fluid intelligence – the ability to solve new problems, reason abstractly and think quickly. Gains have been more modest in so-called crystallised intelligence – the accumulation of knowledge, facts and skills built up over a lifetime. 

More recently, scientists have been puzzled by a seeming departure from this historical upward trend, with scores slowing down, stagnating, or even declining entirely in some countries like Denmark, Australia, and the United States. The picture has become increasingly complicated: different abilities seem to be moving in different directions, with some rising, some flatlining, and some falling. However, one fluid measure continues to buck the trend – the ability for people to rotate imaginary 3D objects in their mind. 

This complexity is what has made the Flynn effect continuously captivate researchers. But most of what we know comes from studies of young people. Older adults have been largely left out of the picture. This is a particularly interesting population to study, as cognitive ageing and the Flynn effect pull in opposite directions in older adults – abilities are declining with age at the same time as generational gains are pushing scores up. This is a fascinating tension that doesn’t exist in younger samples.  

Studying cognitive change in older adults 

This study is the first large-scale systematic look at the Flynn effect specifically in people aged 50 and over, across 22 European countries, spanning nearly two decades (2005-2022) and over 128,000 people.  

Rather than using a single IQ score, psychological researcher Denise Andrzejewski at the University of Vienna and Heriot-Watt University Dubai and colleagues looked at five specific cognitive abilities separately, which is important because different abilities may trend differently over time. 

The five abilities tested from SHARE longitudinal survey data 

The five abilities were chosen because they all tap into executive functioning – the brain's higher-order control system for managing tasks, switching between ideas, and holding information in mind: 

• Verbal fluency — how many animals you can name in 60 seconds 
• Working memory — how many words you can recall immediately from a 10-word list 
• Free recall — how many of those same words you can remember after completing other tasks 
• Numeracy I — basic percentage and fraction calculations 
• Numeracy II — counting backwards from 100 in steps of 7, five times in a row 

Flynn Effect results across five cognitive domains 

Scores went up over time across nearly all abilities and countries — so yes, the Flynn effect applies to older adults too. But the gains were uneven. 

Verbal fluency showed the biggest and most consistent improvements — roughly 4 IQ points per decade. Almost every country improved, with the notable exceptions of Greece (a sharp decline), Israel (a small decline) and Hungary (no change). 

Working memory gains were also strong and consistent at around 3.2 IQ points per decade. Almost every country improved, with Croatia the only exception. 

Free recall improved more modestly at 2.3 IQ points per decade. Most countries showed gains, but several — Israel, Latvia, Poland, and Portugal — showed little to no change, and Croatia again declined slightly. 

Basic numeracy showed small but real gains of less than 1 IQ point per decade, while serial subtraction (counting back from 100 by 7s) was the most inconsistent, with many countries showing virtually no change at all. 

The standout country was Spain, which showed enormous gains across nearly all domains — sometimes approaching 10 IQ points per decade — which the researchers suggest may partly reflect Spain's rapid educational expansion during this period. 

Why might verbal fluency be improving the most? 

This is a particularly interesting finding, because traditionally the Flynn effect has been strongest in fluid/reasoning abilities, not language-based ones. The authors suggest a few explanations: 

• Societal shifts toward more communication-intensive and language-rich environments (media, social interaction, education) may have specifically boosted this skill in recent generations, in a way that numeracy has not benefited from equally 

• Later-born cohorts grew up in healthier, more cognitively stimulating environments, which are known to build cognitive resilience and slow age-related decline. Verbal abilities may be particularly responsive to those advantages 

The role of age and education in cognitive score increases 

When the team statistically accounted for the fact that later cohorts tended to be younger at testing and better educated, the Flynn effects shrank considerably. This suggests a big chunk of the generational improvement is driven by two things: rising education levels across 20th-century Europe – people who were 65 in 2022 had, on average, more schooling than people who were 65 in 2005 – and the fact that even small average age differences between groups matter, because cognitive scores naturally decline with age. 

But some gains remained even after accounting for these factors, particularly in verbal fluency – so it seems other forces are also at work. Have modern lifestyles simply become more cognitively demanding? Has better healthcare preserved more mental capacity into old age? Has widespread technology use – which requires constant learning and adaptation – played a role? 

One striking finding was that generational gains do not seem to reflect a rise in general intelligence (known as psychometric g among scientists) as it is traditionally measured, and the fact that not every ability improved equally is itself telling. These generations aren't getting broadly smarter – they're getting better at specific things, probably because their environments demanded it. 

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Article: Andrzejewski, D., Fries, J., & Pietschnig, J. (2026). Executive Function Flynn Effects are Independent of Psychometric ⁠g in Aging Populations Across Europe (2005-2022). Intelligence & Cognitive Abilities. https://doi.org/10.65550/001c.157760 

Picture via Centre for Ageing Better.