Childhood test scores could predict dementia risk decades before the disease develops, a new study suggests.
Researchers in Sweden followed more than 10,000 people for 60 years, starting in middle school, evaluating the long-term effects of their education on their risk of chronic diseases such as dementia.
At age 13, the participants underwent inductive reasoning tests, which evaluate a person’s decision-making process and abilities.
The team sought to find out if higher cognitive abilities in adolescence could serve as a safeguard against dementia later in life.
Researchers found that children who scored higher on these tests were 16 percent less likely to develop dementia, even after accounting for other risk factors such as education and major illnesses like heart disease.
Tests looking at other cognitive abilities such as spatial and verbal learning did not influence dementia odds, suggesting inductive reasoning specifically may provide a protective factor.
The team cautioned that while the study could not prove that inductive reasoning directly determines dementia risk, there may be several possible mechanisms behind an association.
They explained that inductive reasoning tasks such as sorting groups or recognizing patterns exercise the frontoparietal network, a control hub in the brain that coordinates working memory and has been associated with decline in dementia.
Adolescent scores on inductive reasoning tests may influence the odds of developing dementia later in life, a study suggests
The study comes as seven million Americans are living with dementia, with this number expected to double by 2050.
It’s well documented that lifestyle factors such as poor diet, physical inactivity, alcohol use and isolation raise the risk of the disease, but a growing body of research is focusing on links dating back to childhood and adolescence.
In the new study, published in Alzheimer’s Research & Therapy, researchers recruited 10,539 Swedish 13-year-olds who were born in 1948. The participants took cognitive tests in 1961 measuring inductive reasoning, verbal ability and spatial ability.
Inductive reasoning tests can include completing number sequences, spotting patterns and finding items that do not belong. Testing verbal ability may look at reading comprehension and sentence structure, while spatial tests may evaluate how participants interact with physical objects like puzzle pieces.
In this particular study, the teens were asked to figure out the next number in a sequence, choose opposite words based off a list of choices and mentally picture how folding a sheet of metal would form shapes.
Participants were followed through November 2025. During the study period, 287, or 2.7 percent, had recorded cases of dementia, though it is possible there were additional undocumented incidences.
Researchers used national hospital and death registers to determine diagnoses of dementia, heart disease, diabetes and other major health conditions associated with cognitive decline.
The above graph from the study shows the relationship between childhood inductive reasoning scores and dementia odds. As scores increase, the risk of dementia decreases
Overall, children who scored higher on inductive reasoning tests at age 13 were 16 percent less likely to develop dementia in older age. The team found each additional point scored on these tests was linked to a two percent drop in dementia risk.
However, the other two tests were not associated with a decline in dementia development.
Researchers adjusted for education levels in both the participants and their parents.
They also found that while heart disease and diabetes have been associated with higher risk of dementia due to blood vessel damage and inflammation, 58 percent of participants with dementia did not have these conditions, suggesting vascular health is not fully responsible for dementia development.
The team also replicated the findings with a cohort of 19,919 people born in 1953, which found a 15 percent lower dementia risk with higher inductive reasoning scores.
In addition to inductive reasoning exercising brain structures that become damaged in dementia, the researchers suspect it may be related to ‘system integrity,’ which is a tendency for people with stronger cognitive function early in life to have better function in multiple systems, such as brain, heart and metabolic health.
The team cautioned that they could not account for other factors related to dementia such as prenatal health, genetics, lifestyle behaviors in adulthood and specific subtypes of dementia.
They said future studies can further assess this relationship and explore if cognitive development in childhood could prevent dementia.
