Does More Schooling Reshape Your Brain? Surprising Findings From a Massive “Natural Experiment”

MRI data reveals no structural brain changes from an extra school year, hinting that education’s benefits may not extend to brain aging.

Through a “natural experiment” involving 30,000 people, researchers at Radboud University Medical Center set out to understand the long-term impact of an additional year of education on the brain. Analyzing extensive data, they discovered something unexpected: an extra year of schooling showed no effect on brain structure or protection against brain aging.

The Benefits of Education

Education is widely recognized for its many positive effects. People who spend more time in school often enjoy better health, cognitive abilities, job prospects, and income. However, whether prolonged education directly influences brain structure or protects it from aging over time remained an open question.

This type of study is challenging, as brain structure is shaped by a mix of influences beyond education, including genetics, upbringing, and environmental factors. Despite these complexities, researchers Rogier Kievit and Nicholas Judd from Radboudumc and the Donders Institute seized a rare opportunity to rigorously examine the effects of an extra year of schooling, thanks to the unique conditions of this natural experiment.

Natural Experiment and Unique Dataset

In 1972, a change in the law in the United Kingdom raised the number of mandatory school years from fifteen to sixteen, while all other circumstances remained constant. This created an interesting “natural experiment,” an event not under the control of researchers that divides people into an exposed and unexposed group.

Data from approximately 30,000 people who attended school around that time, including MRI scans taken much later (46 years after), is available. This dataset is the world’s largest collection of brain imaging data.

Surprising Findings on Brain Aging

The researchers examined the MRI scans for the structure of various brain regions, but they found no differences between those who attended school longer and those who did not.

“This surprised us,” says Judd. “We know that education is beneficial, and we had expected education to provide protection against brain aging. Aging shows up in all of our MRI measures, for instance, we see a decline in total volume, surface area, cortical thickness, and worse water diffusion in the brain. However, the extra year of education appears to have no effect here.”

Temporary Effects and Possible Explanations

It’s possible that the brain looked different immediately after the extra year of education, but that wasn’t measured.

“Maybe education temporarily increases brain size, but it returns to normal later. After all, it has to fit in your head,” explains Kievit. “It could be like sports: if you train hard for a year at sixteen, you’ll see a positive effect on your muscles, but fifty years later, that effect is gone.” It’s also possible that extra education only produces microscopic changes in the brain, which are not visible with MRI.

Education, Cognition, and Health Correlations

Both in this study and in other, smaller studies, links have been found between more education and brain benefits. For example, people who receive more education have stronger cognitive abilities, better health, and a higher likelihood of employment. However, this is not visible in brain structure via MRI.

Kievit notes: “Our study shows that one should be cautious about assigning causation when only a correlation is observed. Although we also see correlations between education and the brain, we see no evidence of this in brain structure.”

Reference: “No effect of additional education on long-term brain structure – a preregistered natural experiment in thousands of individuals” by Nicholas Judd and Rogier Kievit, 5 November 2024, eLife.
DOI: 10.7554/eLife.101526.1

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