Walking Speed and Intelligence: Do Fast Walkers Have Higher IQs?

Walking speed and intelligence are genuinely related: in a New Zealand birth cohort, adults whose walking speed at age 45 fell in the slowest fifth scored on average 16 IQ points lower than those in the fastest fifth, a standardized association of about .38. The link reflects shared brain and body health over a lifetime, so it works as a marker of aging, and there is no evidence that walking faster raises anyone's IQ.

This article covers the Dunedin study behind the 16-point figure, what research on older adults shows, why the link exists, the confounds that inflate it, and what the age a baby first walks does (and does not) predict.

The strongest single source is a 2019 paper in JAMA Network Open by Line Jee Hartmann Rasmussen, Avshalom Caspi, Terrie Moffitt and colleagues. They used the Dunedin Multidisciplinary Health and Development Study, which has followed 1,037 people born in Dunedin, New Zealand, in 1972 and 1973 since age 3. At age 45, 904 of them walked across an electronic walkway under three conditions: at their normal pace, at normal pace while reciting alternate letters of the alphabet ("dual task" walking), and as fast as they safely could. The average of the three gave a composite gait speed.

The results were consistent across every measure:

• Adult IQ: participants with lower full-scale IQ on the Wechsler Adult Intelligence Scale (WAIS-IV) at 45 walked more slowly (standardized coefficient β = .38). The slowest fifth of walkers scored 16 IQ points below the fastest fifth, which is more than one standard deviation.

• Specific abilities: slow walkers also scored lower on processing speed, working memory, perceptual reasoning and verbal comprehension, with coefficients between .29 and .32.

• Childhood: poorer "brain health" at age 3, a composite of a pediatric neurological exam, tests of intelligence, language and motor skills, and examiner ratings of behavior, predicted slower walking 42 years later (β = .26). The gap between the slowest and fastest quintiles was 0.62 standard deviations, and the link held after controlling for childhood socioeconomic status.

• Cognitive decline: people whose IQ scores fell between childhood (ages 7 to 11) and age 45 walked more slowly, although this effect was small (β = .10).

Slow walkers also had smaller brain volume, thinner cortex, weaker grip strength and faces that a panel rated as older. Their bodies, in other words, seemed to be aging faster on several fronts at once.

A standardized coefficient of .38 is roughly equivalent to a correlation of .38, which is moderate by the standards of psychology. It means walking speed carries real information about IQ at the group level, and it is still far too weak to estimate any one person's IQ from how fast they walk.

Most gait research comes from older adults, where walking speed is a standard clinical measure. A pooled analysis of nine cohorts by Stephanie Studenski and colleagues, covering 34,485 people aged 65 and older, found that every 0.1 meter per second of extra gait speed was associated with lower mortality (hazard ratio 0.88). Physical therapists Stacy Fritz and Michelle Lusardi went as far as calling walking speed "the sixth vital sign" in a 2009 white paper.

For cognition, a 2016 meta-analysis in Gait & Posture by Naiara Demnitz and colleagues pooled 26 cross-sectional studies with 26,355 healthy older participants. Faster gait went with better global cognition (pooled effect size 0.12), executive function (0.20) and processing speed (0.15). These are small effects. Expressed on the IQ scale, an effect of 0.12 standard deviations would be a bit under 2 points. The authors also found signs of publication bias, and correcting for it shrank the estimates slightly.

The Lothian Birth Cohort 1936 adds a long view. Judith Okely and Ian Deary followed 1,091 Scottish adults from age 70 to 79, timing a 6-meter walk every three years. At age 70, slower walking correlated r = .39 with slower processing speed. That fell to .22 after adjusting for IQ measured at age 11, height and chronic disease, which shows that part of the link reflects lifelong differences in ability. Over the following decade, people whose walking slowed most also declined most in processing speed (r = .49) and memory (r = .32). The two declines moved together, but after adjusting for covariates the data could not show that slowing gait caused cognitive decline or the reverse.

Our article on measuring cognitive aging with memory and processing speed tasks explains why processing speed is usually the first ability to show age-related change, which fits these results.

Walking feels automatic, but it draws on vision, balance, muscle strength, heart and lung capacity and the brain's control of movement. The Dunedin authors proposed six possible reasons for the link with cognition. Two of them are biological. Walking and thinking may depend on the same brain networks and white matter, and the brain may be a sensitive early indicator of the body's overall condition. A shared genetic influence on brain and physical health is another possibility.

The rest run through the environment and behavior. People with better cognitive ability tend to get more education, work in safer jobs, smoke less, exercise more and use health care more effectively, and those habits keep the body in better shape. On this view, intelligence helps produce good health over decades, and gait speed simply records the result.

Speed itself may also matter. Simple speed measures are among the oldest correlates of IQ studied by psychologists, and our article on the correlation between IQ and reaction time covers the strongest of them. The Dunedin data showed the largest effects for the two challenging walks, especially maximum speed, and the dual-task walk explicitly mixes thinking with moving.

The walking speed and intelligence correlation is real, but several factors can make it look stronger or more meaningful than it is:

• Health and disease: chronic illness, obesity and injuries slow walking and can also affect test performance. In the Lothian cohort, adjusting for chronic disease, height and childhood IQ together cut the correlation by almost half.

• Socioeconomic status: family background relates to both health and IQ. In Dunedin, the childhood link survived adjustment for childhood SES, but the association with white matter lesions did not.

• Age: in older samples, age slows both walking and processing speed, so studies must compare people of the same age. Dunedin and Lothian avoid this problem because everyone was born within about a year.

• Direction of cause: none of these studies were experiments. Walking faster, or training to walk faster, has never been shown to raise IQ. Whether physical activity changes cognitive test scores is a separate question, covered in our article on whether exercise can affect your IQ score.

Dunedin also measured gait only once, at 45, and the cohort was 93% white, so the findings may not apply equally to every population.

Parents often wonder whether an early walker will be a bright child. The evidence in healthy children says no. Oskar Jenni and colleagues followed 222 healthy, full-term children in the Zurich Generational Study, whose parents recorded the date of each child's first independent steps. Half walked by 12 months, and 80% did so between 10.5 and 16 months. IQ was then tested repeatedly from age 7 to 18. The age of walking was unrelated to later IQ, and its only link was a weak one with balance tasks.

A 2021 Swiss study of 555 preschoolers by Nadine Messerli-Bürgy and colleagues found that later walking onset was associated with somewhat poorer selective attention and visual perception at ages 2 to 6. The authors described walking onset as a poor predictor overall, and the Zurich results suggest that such early differences fade by school age. Very late walking (Jenni's team mentions after about 18 to 20 months) is a reason to talk with a pediatrician, since it can signal a developmental problem, and the age of first steps is not a gauge of intelligence.

At the group level, faster walkers tend to have somewhat higher IQ scores, with a correlation of around .4 in a large midlife cohort. The link is too weak to judge an individual's intelligence from their pace.

On average, yes, slightly. In the Dunedin study the fastest fifth of 45-year-old walkers scored about 16 IQ points higher than the slowest fifth, mostly because walking speed tracks overall brain and body health.

There is no evidence that it can. The studies are correlational, and the link appears to reflect shared health and aging processes.

Gait speed predicts survival, disability and later cognitive decline in older adults. It is quick, cheap and safe to measure, which makes it a useful clinical screening tool.

No. In a Zurich study that followed healthy children to age 18, the age of first walking was unrelated to later IQ.

Gait speed carries a real but modest signal about intelligence, strongest in older age and in demanding walking tasks, because walking and thinking draw on the same aging brain and body. A brisk pace is a sign of good health that tends to accompany good cognition, and it cannot stand in for a measurement of reasoning ability. If you want that measurement, take the RIOT IQ test, which compares your performance with a representative norm group.

1. Demnitz, N., Esser, P., Dawes, H., Valkanova, V., Johansen-Berg, H., Ebmeier, K. P., & Sexton, C. (2016). A systematic review and meta-analysis of cross-sectional studies examining the relationship between mobility and cognition in healthy older adults. Gait & Posture, 50, 164-174. [doi.org/10.1016/j.gaitpost.2016.08.028](. doi.org

2. Fritz, S., & Lusardi, M. (2009). White paper: "Walking speed: The sixth vital sign". Journal of Geriatric Physical Therapy, 32(2), 2-5. [doi.org/10.1519/00139143-200932020-00002](. doi.org

3. Jenni, O. G., Chaouch, A., Caflisch, J., & Rousson, V. (2013). Infant motor milestones: Poor predictive value for outcome of healthy children. Acta Paediatrica, 102(4), e181-e184. [doi.org/10.1111/apa.12129](. doi.org

4. Messerli-Bürgy, N., Kakebeeke, T. H., Meyer, A. H., Arhab, A., Zysset, A. E., Stülb, K., Leeger-Aschmann, C. S., Schmutz, E. A., Kriemler, S., Puder, J. J., Munsch, S., & Jenni, O. G. (2021). Walking onset: A poor predictor for motor and cognitive skills in healthy preschool children. BMC Pediatrics, 21, 367. [doi.org/10.1186/s12887-021-02828-4](. doi.org

5. Okely, J. A., & Deary, I. J. (2020). Associations between declining physical and cognitive functions in the Lothian Birth Cohort 1936. The Journals of Gerontology: Series A, 75(7), 1393-1402. [doi.org/10.1093/gerona/glaa023](. doi.org

6. Rasmussen, L. J. H., Caspi, A., Ambler, A., Broadbent, J. M., Cohen, H. J., d'Arbeloff, T., ... Moffitt, T. E. (2019). Association of neurocognitive and physical function with gait speed in midlife. JAMA Network Open, 2(10), e1913123. [doi.org/10.1001/jamanetworkopen.2019.13123](. doi.org

7. Studenski, S., Perera, S., Patel, K., Rosano, C., Faulkner, K., Inzitari, M., ... Guralnik, J. (2011). Gait speed and survival in older adults. JAMA, 305(1), 50-58. [doi.org/10.1001/jama.2010.1923](. doi.org

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