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For a long time, science has attempted to define a "universal golden age" of our cognitive faculties. But recent research paints a much more nuanced picture. Here's a closer look.
Peak cognitive speed at 24?
In 2014, a study conducted by researchers from Simon Fraser University in Burnaby (Canada) and published in the journal Plos One had made an impression: she concluded that at the age of 24, our cognitive abilities reach their peak.
The scientists reached this conclusion based on the performance of 3,305 people, aged 16 to 44, playing StarCraft 2, a real-time strategy PC game set in a galaxy where three factions must fight each other. A game that requires concentration, skill, strategy, and speed. According to the researchers' analysis, after the age of 24, cognitive speed and performance decline: between a 39-year-old player and a 24-year-old player, the difference in game speed could reach a total of 30 seconds in a 15-minute game, a significant gap in this video game.
But while older players may become slower, they are also the ones who manage to implement tricks and other strategies to compensate for this decline in responsiveness, the scientists emphasized, adding that performance is the result of the constant interaction between this change and the brain's adaptation to be more efficient. Cognitive decline must therefore be put into perspective, because a well-trained brain is capable of compensating for this decline in raw performance to find its efficiency in other ways.
Skills that continue to grow into your fifties
This study, however, suggests that intelligence could be represented graphically in the form of a bell, with a maximum reached at a certain point, then inevitably exceeded. But the reality is more complex. Research published since then shows that there is not "one" age of peak intellectual abilities, but several, depending on the faculties considered.
A large study involving 48,537 participants and published in the journal Psychological Science in 2015 revealed that some skills, such as reasoning speed or short-term memory, peak in early adulthood (18-20 years old). On the other hand, other skills, particularly those related to acquired knowledge (vocabulary, general knowledge, language comprehension), continue to grow until one's forties or even fifties.
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Individual variations
This "asynchrony" has been confirmed by more recent research. In 2025, a study published in the journal Science Advances showed that literacy skills (the ability to read, understand, and use written information in everyday life) and numeracy skills (the ability to use, apply, interpret, communicate, and critique mathematical information and ideas in everyday life) progress until around the age of 40, before stabilizing and then slowly declining. Similarly, a meta-analysis of 39 brain imaging studies on cognitive control, published in the journal NeuroImage in 2024, concluded that attention management and distraction resistance functions reach their optimum between the ages of 27 and 36.
Cognitive trajectory also varies greatly from one individual to another. Genetic factors, education level, occupation, lifestyle habits, physical and mental health influence the rate of evolution of different functions. The idea of a fixed age, common to all, therefore appears obsolete. Scientists prefer to speak of "peak performance periods" that differ depending on the individual and the domain.
The major influence of lifestyle
The good news is that these trajectories are not fixed. Neuroscientists have been emphasizing for several years the importance of " cognitive reserve", that is, the brain's ability to compensate for its losses through training, learning and intellectual stimulation. Regular physical activity, balanced diet, intellectual curiosity (especially long studies) and a rich social life are all levers capable of delaying the age of cognitive decline and reducing the risk of developing neurodegenerative diseases such as Alzheimer's.
Thus, there is no "one" age of peak intellectual ability, but a series of peaks spread throughout adulthood. The twenties excel in processing speed and short-term memory, the thirties shine in attention control, the forties in wealth of knowledge, and the fifties still retain an edge in vocabulary and accumulated expertise. Rather than a single curve, our intelligence resembles a mountain range, each peak of which is reached at a different time.
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