# IQ and Longevity: 15 Points Higher, 24% Lower Risk of Death?

> Many follow-up studies have confirmed that people with a higher IQ in childhood tend to live longer. In a meta-analysis of 16 cohorts and about 1.1 million people, an IQ one standard deviation (15 points) higher was associated with a 24% lower risk of death later on (Calvin and colleagues, 2011). A study that followed 65,765 people in Scotland for 68 years after their IQ was measured at age 11 found that the higher the IQ, the lower the risk for nearly every major cause of death, including respiratory disease, heart disease, stroke, and dementia. The association weakened by 54% when education was taken into account and by 34% when adult socioeconomic status was taken into account, and in a twin study most of the correlation between intelligence and lifespan was explained by genetics. Individual differences are large, though, and IQ cannot predict how long a person will live.

- URL: https://brainrank.jp/en/blog/iq-and-longevity
- Published: 2026-09-28
- Publisher: BrainRank Editorial Team (https://brainrank.jp)
- Tags: Psychology, Cognitive abilities

IQ and longevity are related: follow-up studies spanning decades have repeatedly confirmed that people with a higher IQ in childhood live longer on average. The field that studies how intelligence relates to health and mortality is called "cognitive epidemiology." This article lays out how large the association is in the main studies, how it differs by type of disease, why the association arises, and what you can do regardless of IQ.

## The bottom line: 15 more IQ points, about 24% lower risk of death

A meta-analysis pooling 16 follow-up studies (about 1.1 million participants, 22,453 deaths, 17 to 69 years of follow-up) found that an IQ one standard deviation (15 points) higher in childhood or early adulthood was associated with a **24%** lower risk of death later on ([Calvin and colleagues, 2011, International Journal of Epidemiology](https://doi.org/10.1093/ije/dyq190)). Expressed as a hazard ratio, that is about 0.76.

A study that followed about 990,000 Swedish men for about 20 years after they took an intelligence test at around age 18 likewise found that an IQ one standard deviation lower was associated with 1.32 times the risk of death, with a stepwise difference across the entire IQ range ([Batty and colleagues, 2009, Epidemiology](https://doi.org/10.1097/EDE.0b013e31818ba076)). The notable feature is that it is not only people with a high IQ who stand apart; the association appears as a smooth gradient from the low end of the IQ range to the high end.

## The Scottish study that followed 65,000 11-year-olds for 68 years

In Scotland, in 1932 and again in 1947, almost every child who was 11 years old that year was given an intelligence test. A follow-up of 2,792 people in Aberdeen who took part in the 1932 survey found that those with an IQ 15 points lower were 21% less likely to survive to age 76 (relative risk 0.79, [Whalley & Deary, 2001, BMJ](https://doi.org/10.1136/bmj.322.7290.819)).

A study that followed 65,765 people who took part in the 1947 survey for 68 years, until 2015, also examined the association by cause of death ([Calvin and colleagues, 2017, BMJ](https://doi.org/10.1136/bmj.j2708)). The risk of death (hazard ratio) for an IQ one standard deviation higher was as follows.

| Cause of death | Hazard ratio (per +1 SD of IQ) | How much lower the risk |
| --- | --- | --- |
| Respiratory disease | 0.72 | About 28% lower |
| Coronary heart disease | 0.75 | About 25% lower |
| Stroke | 0.76 | About 24% lower |
| Injury | 0.81 | About 19% lower |
| Smoking-related cancers | 0.82 | About 18% lower |
| Digestive disease | 0.82 | About 18% lower |
| Dementia | 0.84 | About 16% lower |

The important point is that the association runs in the same direction not just for particular diseases but for nearly every major cause of death. Even after the family's socioeconomic status in childhood was taken into account, the associations weakened by only 10 to 26%.

## Why do people with a higher IQ tend to live longer? 4 explanations

Several explanations have been proposed for why this association arises, and no single one of them accounts for it completely.

### 1. Education and socioeconomic status

People with a higher IQ tend to stay in education longer and to have an advantage in income and occupation, which leads to better access to medical care and better living conditions. In the 2011 meta-analysis, the association between IQ and mortality weakened by **54%** when education was taken into account and by **34%** when adult socioeconomic status was taken into account (Calvin and colleagues, 2011). Around half of the association can be said to run through education and income. The links between education and intelligence are also covered in [IQ and grades](https://brainrank.jp/en/blog/iq-and-grades) and [IQ and income](https://brainrank.jp/en/blog/iq-and-success).

### 2. Health knowledge and behavior (health literacy)

Preventing and treating illness is a continuous series of tasks that require understanding information and acting on it: managing medication, judging symptoms, changing lifestyle habits. The psychologist Gottfredson argued that general intelligence may be the fundamental cause of social inequalities in health. The basis for the argument is that it can explain why those inequalities appear regardless of era, country, disease, or health care system ([Gottfredson, 2004](https://doi.org/10.1037/0022-3514.86.1.174)). A 2021 review likewise names education, socioeconomic status, and health literacy as the main mediating factors ([Deary, Hill & Gale, 2021, Nature Human Behaviour](https://doi.org/10.1038/s41562-021-01078-9)).

### 3. Genetics

In twin data from the United States, Sweden, and Denmark, the correlation between intelligence and lifespan was small, at r=0.12, but **84 to 95%** of that correlation was explained by genetics ([Arden and colleagues, 2016, International Journal of Epidemiology](https://doi.org/10.1093/ije/dyv112)). This suggests that genes involved in intelligence may partly overlap with genes involved in physical health. The genetics of intelligence is explained in [is IQ genetic?](https://brainrank.jp/en/blog/iq-genetics).

### 4. The condition of the whole body (system integrity)

This is the hypothesis that performance on intelligence tests reflects how well the whole body, including the brain, is functioning, and that this also shows up in lifespan. The idea is still at a stage where even Deary, who proposed it, says it is not yet sufficiently developed either theoretically or empirically ([Deary, 2012, Gerontology](https://doi.org/10.1159/000341157)).

## Limitations to keep in mind

These are average tendencies across whole populations. Even in the study by Arden and colleagues, the correlation between intelligence and lifespan was only about 0.12, and there are plenty of people with a high IQ who die young and plenty with a low IQ who live long. An individual's lifespan cannot be predicted from IQ.

These are also observational studies, so they do not show a causal relationship of the kind "raise your IQ and you will live longer." The fact that around half of the association runs through education, income, and lifestyle means, looked at the other way, that there is room to narrow the gap by changing those things.

## What you can do to live longer, regardless of IQ

Following the pathways the research points to shows what anyone can work on, regardless of IQ.

- Don't smoke: smoking-related cancers, respiratory disease, and heart disease are major causes of death that showed an association with IQ
- Exercise and sleep: aerobic exercise and enough sleep matter not only for physical health but also for maintaining cognitive function ([exercise and the brain](https://brainrank.jp/en/blog/exercise-and-brain), [sleep and cognitive function](https://brainrank.jp/en/blog/sleep-and-cognition))
- Get health checkups and ask about what you don't understand: check test results and medication instructions with your doctor or pharmacist until you understand them
- Keep learning: education and mentally stimulating activity are also linked to [cognitive reserve](https://brainrank.jp/en/blog/cognitive-reserve), which helps buffer against cognitive decline

## How to get an estimate of your own IQ

IQ does not determine how long you live, but knowing your own cognitive strengths and weaknesses can prompt you to think about how you deal with information. [BrainRank's free IQ test](https://brainrank.jp/en/start) scores 20 questions (about 10 minutes) across four domains, spatial reasoning, pattern recognition, logical reasoning, and classification, using item response theory (IRT), and returns an estimated IQ on a mean-100, SD-15 scale. Taking it is free with no signup; viewing the results, including the estimated IQ, is a one-time payment of ¥300 (tax included), with no subscription or auto-renewal (the result can be reopened for 24 hours after it is first shown, and saved as an image or PDF during that window). Results are estimates for entertainment and self-understanding, not a medical or diagnostic assessment.

## Frequently asked questions

### Do people with a high IQ really live longer?

On average across a population, they tend to. A meta-analysis pooling 16 follow-up studies and about 1.1 million people found that each 15-point increase in childhood IQ was associated with a 24% lower risk of death later on. This is a tendency across the whole population, though: the correlation between intelligence and lifespan is itself small, at around 0.12, and IQ alone cannot predict any one person's lifespan.

### Why do people with a higher IQ tend to live longer?

Several explanations are thought to work in combination. Education and adult socioeconomic status explain part of the association (about 54% and 34%, respectively), and health literacy, the ability to understand health information and act on it, and lifestyle habits such as smoking are also involved. In a twin study, 84 to 95% of the correlation between intelligence and lifespan was explained by genetics. A "system integrity" hypothesis, the idea that a body in good overall condition shows up in both intelligence and lifespan, has also been proposed, but it has not been adequately tested.

### Does a low IQ mean a shorter life is inevitable?

No. Around half of the association runs through education, income, and lifestyle, and those are things that personal choices and social support can change. Actions anyone can take regardless of IQ have a large effect on lifespan: quitting smoking, exercising, sleeping well, getting health checkups, and asking a doctor or pharmacist about health information you don't understand.

## Sources

- [Calvin and colleagues, 2011, International Journal of Epidemiology](https://doi.org/10.1093/ije/dyq190)
- [Batty and colleagues, 2009, Epidemiology](https://doi.org/10.1097/EDE.0b013e31818ba076)
- [Whalley & Deary, 2001, BMJ](https://doi.org/10.1136/bmj.322.7290.819)
- [Calvin and colleagues, 2017, BMJ](https://doi.org/10.1136/bmj.j2708)
- [Gottfredson, 2004](https://doi.org/10.1037/0022-3514.86.1.174)
- [Deary, Hill & Gale, 2021, Nature Human Behaviour](https://doi.org/10.1038/s41562-021-01078-9)
- [Arden and colleagues, 2016, International Journal of Epidemiology](https://doi.org/10.1093/ije/dyv112)
- [Deary, 2012, Gerontology](https://doi.org/10.1159/000341157)

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Statistics and percentages are calculated from a normal distribution model with a mean of 100 and a standard deviation of 15. The tests on this site provide estimates for entertainment and self-understanding; they are not medical or clinical assessments, nor official intelligence tests.
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