Middle-aged and older adults lament that their memory is not what it used to be. Literacy, the ability to read and comprehend, and mathematical skills, the ability to calculate quickly and accurately, are believed to be closely related to age. Contrary to common belief, research findings show that literacy and mathematical skills do not necessarily decline with age.
Cognitive abilities peak in the 40s and then decline. However, if reading and mathematical skills are consistently utilized in the workplace or daily life, cognitive abilities do not decline even into the 60s. Previous studies have also shown that frequent engagement in leisure activities keeps the risk of dementia low. These results provide hope that one can live with a youthful brain even as they age.
A joint research team from the Technical University of Munich and Stanford University in the United States announced on the 5th (local time) the results of a study examining how cognitive abilities such as literacy and mathematical skills vary with age among German adults. The research findings were published in the international academic journal Science Advances.
The research team analyzed data from the Program for the International Assessment of Adult Competencies (PIAAC), which assesses language and mathematical skills of the German population aged 16 to 65. This survey measures how cognitive abilities change with age by evaluating language and math skills on the same subjects every three and a half years. The total number of German adults analyzed by the research team was 3,263.
The analysis revealed that literacy and mathematical skills were generally correlated with age. Literacy sharply increased in one's 20s and 30s, peaking at an average age of 46 before gradually declining. However, even in their mid-60s, literacy remained higher than that of individuals in their early 20s.
Mathematical skills also increased until the 20s and 30s, peaking at an average age of 41 before declining rapidly. By their 60s, mathematical skills dropped to levels similar to those in the early 20s. The decline in mathematical skills was more pronounced than in literacy. Additionally, it was found that as age increases, women's mathematical skills decline more sharply than men's.
However, some individuals did not experience the aging curve phenomenon, which typically begins in the early to mid-40s. In fact, both literacy and mathematical skills gradually increased up to their mid-60s.
Analysis of people who did not experience cognitive decline revealed that there were many white-collar workers or individuals with higher education. The research team noted, "The reason white-collar workers or highly educated individuals do not see their cognitive abilities decrease with age is that they consistently use skills related to literacy and mathematical abilities in their workplace or at home."
White-collar workers are exposed to tasks involving document or report preparation, and calculation, significantly increasing their chances of developing skills that maintain cognitive abilities. However, the differences in cognitive abilities are not simply divided along the lines of education level, occupation, salary, or gender.
To verify this fact, the research team also categorized the subjects based on their usage of cognitive skills. Groups that frequently used skills related to literacy and mathematical abilities showed a consistent increase in cognitive ability scores after the age of 50, regardless of occupation or education level. In contrast, groups with lower usage of these skills began to see a decline in cognitive abilities from their mid-30s, with a more significant drop by the time they reached their 40s.
The research team explained, "Not only does simply reading books at home matter, but assessing how much one utilizes mathematical abilities in their work yields the same results," adding, "Examining the correlation between age and cognitive abilities of adults illustrates how crucial lifelong learning can be."
Previous studies have also indicated that engaging in leisure activities that stimulate the mind helps maintain cognitive abilities. In 2023, a research team from Monash University in Australia published findings in the JAMA Network Open, stating that activities like puzzles, card games, chess, and adult education classes could reduce the risk of dementia by up to 11%.
The research team analyzed a decade's worth of data from 10,000 Australian adults aged 70 and above to investigate the relationship between various leisure activities and dementia. Activities that directly utilized literacy showed a greater preventative effect against dementia compared to merely watching the news or socializing.
Researchers from Tohoku University in Japan also announced in 2023 that individuals participating in adult education requiring literacy and calculation skills had an average dementia risk reduction of about 19%, based on the analysis of medical information from more than 28,000 participants registered in the UK Biobank.
The research team pointed out that these findings contradict the common perception that cognitive abilities inevitably decline with age. It suggests that being in an environment where skills are frequently used can actually lead to improved cognitive abilities regardless of aging, indicating that the equation 'aging = decline in labor productivity' does not necessarily hold.
The research team stated, "Those who continue to receive stimulation and learning opportunities maintain brain plasticity, allowing their brain functions to remain intact or even improve, irrespective of age," suggesting that policies aimed at increasing educational and training opportunities for middle-aged and older adults while encouraging lifelong learning could significantly preserve human capital.
References
Science Advances (2025), DOI: https://doi.org/10.1126/sciadv.ads1560
JAMA Network Open (2023), DOI: https://doi.org/10.1001/jamanetworkopen.2023.23690
Frontiers in Aging Neuroscience (2023), DOI: https://doi.org/10.3389/fnagi.2023.1212623