How to build children’s ‘cognitive endurance’ in a distracted age

You’re halfway through a difficult exam when you notice your concentration starting to slip. The words on the page blend together and you find yourself thinking about what you’re going to have for dinner that night. Does this sound familiar? This mental fatigue is not a character flaw: it is a universal human experience that reveals something essential about how people’s minds work.

We are behavioral scientists who study how economic circumstances shape human cognition and behavior. In a recent study of more than 1,600 children, we found that the ability to sustain mental effort over time – or “cognitive endurance” – works much like physical endurance. Almost universally, the more time people spend on a task, the less successful they are at it. But just as athletes can train to run longer distances, children are able to strengthen their capacity for sustained thinking through simple but dedicated practice, allowing them to continue performing at a higher level for longer periods of time. At a time of social media and short content Designed to minimize mental friction and require minimal effort, the skill of sustained thinking is perhaps less practiced than ever, making it more important to understand how it develops and how it can be strengthened.

Could the environment influence concentration?

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A few years ago, while analyzing standardized test scores from around the world with our colleagues Christina Brown of the University of Chicago and Geeta Kingdon of University College London, we noticed a remarkably consistent trend: Students performed worse on questions appearing later in exams, even after accounting for question difficulty.

This decline in performance was much greater among students from disadvantaged backgrounds. Children in poor countries experienced a decline in performance three times faster than those in rich countries. This could be because disadvantaged children have fewer opportunities to develop their concentration. Cognitive skills generally improve with deliberate, focused and progressively more challenging training. And looking at what activities children spent time on at school, we found that wealthier students were more likely to engage in independent, focused practice by doing activities such as solving problems on their own, reading silently, or focusing on individual tasks. In contrast, students in disadvantaged schools were more likely to spend much of the day in passive activities such as listening to lectures, practicing rote memorization, or copying from the board.

These patterns suggest that the school experience itself—particularly the amount of sustained mental effort the school day demands—could shape students’ cognitive endurance.

Train the mind like a muscle

To test whether cognitive endurance could be improved, we designed an experiment with 1,636 students at a primary school in India. Students were randomly assigned to one of three groups during their study periods. Members of the control group continued their usual routine: copying a few math problems from the board before spending most of the class time at their leisure, resulting in minimal sustained mental effort.

In contrast, the other two “treatment” groups engaged in 20 minutes of continuous cognitive practice during these study periods. Members of one group solved math problems on tablets in a simple app that scaled to their skill level, but had no gamified features to hold their attention. This gave these students focused practice in a specific area. But it was also possible that simply practicing concentration, regardless of the task, could increase mental stamina. To test this, the final group completed cognitively demanding games, such as mazes and shape puzzles called tangrams, which contained no academic content. These app-based games also scaled their difficulty based on performance, making them challenging for students.

The results were striking. Both treatment groups showed significant improvements in their ability to maintain performance throughout testing, regardless of the type of training they received. When students took assessments of listening comprehension, reasoning, or math, the performance of those who received cognitive practice declined 22 percent more slowly than that of students in the control group. It didn’t matter whether the students practiced with academic content or with non-academic games: the benefits were almost identical for both groups. This suggests that the act of focusing mattered more than what the students focused on.

Students who practiced focusing also improved on standardized tests of sustained attention, including those that tested their reaction times or their ability to spot target symbols hidden in a grid. They also demonstrated better concentration in class, according to their teachers’ assessments: for example, they fidgeted less and followed instructions in several steps. This appears to have translated into better grades across a wide range of subjects as well: students who took either form of cognitive practice scored about 0.09 standard deviations higher in Hindi, English and mathematics than those who did not. In comparison, this effect was about half to three-quarters as large as that of assign a student to a class with seven fewer students per teacher. These were substantial improvements, given that the intervention only required 20 to 50 minutes per week for six months.

Beyond the classroom

The implications of these findings extend beyond education. We also found that disadvantaged groups, whose members are likely to have received less practice maintaining concentration, show faster declines in performance over time in other contexts. For example, we found that data entry workers made more errors as their work progressed and that workers with less education had much steeper declines. Even voting behavior reflects these trends: studies have shown that when a given proposition appears later on the ballot in California, voters are more likely to choose the default option. We have shown that these declines are particularly pronounced in working-class neighborhoods.

These findings suggest that differences in cognitive endurance that arise from inequalities in the education system could contribute to broader inequalities later in life. But by demonstrating that mental toughness can be improved, the findings also indicate the types of programs that can begin to level the playing field for less advantaged students.

We still need to do more research to identify the most effective training methods. For now, it appears that activities as diverse as solving difficult puzzles, learning a musical instrument, or even playing certain video games could help develop cognitive endurance, as long as they require sustained, deliberate, and proactive mental effort. This training could benefit anyone who may be exposed to fewer periods of sustained concentration as the world moves toward greater engagement with endless bite-sized social media scrolls.

The message is hopeful: your capacity for cognitive endurance is not fixed. Like physical fitness, it can be developed through practice.