Average Reaction Time by Age, and What It Says About IQ
A typical simple reaction time is roughly 200 to 270 milliseconds, but the device and the task move it more than age does. In UK samples it correlates about -.3 with a timed intelligence test.
What you need to know
- There is no single average reaction time. Human Benchmark's median is 273 ms over more than 81 million clicks, a calibrated lab sample of 1,469 adults averaged 213 ms, and a UK survey of 900 people aged about 56 averaged 358 ms. Device, stimulus and task decide the number.
- Age slows the hand more than the eye. In a calibrated study, simple reaction times rose 0.55 ms per year of age, from about 200 ms in the youngest group to 222 ms in the oldest (ages 18 to 65), while detection time stayed near 131 ms at every age.
- Reaction time does correlate with IQ, modestly: -.31 for simple and -.49 for four-choice reaction time in 900 people aged about 56, and -.27 to -.32 for simple reaction time across ages 30 to 69 in 2,196 people. That is 7% to 10% of the variance for simple reaction time, so a click test cannot estimate IQ.
- The claim that Victorians were about 13 IQ points cleverer rests on Galton's reaction times, and it is contested: one team estimates a decline of 1.16 IQ points per decade, critics say cross-study comparisons are uninformative, and a calibrated study found no slowing.
There is no single average reaction time. A typical simple reaction time to a visual signal is roughly 200 to 270 milliseconds in the sources below, but the figure depends on the device, the task and the sample more than on the person. The link between reaction time and IQ is real but modest, about -.3 for simple reaction time in UK population samples. This guide sets out the averages, how they change with age, what the correlation means in IQ points, and why the claim that Victorians were quicker, and so cleverer, is contested.
What is a normal reaction time?
Human Benchmark, the most-used online reaction test, says on its statistics page that the median reaction time is 273 milliseconds and the average is 284, from more than 81 million recorded clicks. Those are clicks, not people, and the pages we read give no count of users. Its test page warns that while an average human reaction time may fall between 200 and 250 ms, your computer could be adding 10 to 50 ms on top, and its statistics page calls 30 ms a typical lag for a desktop or laptop.
Laboratory and survey figures differ. A review by Robert Kosinski at Clemson University, last updated in September 2013, puts mean visual reaction times at 180 to 200 ms, auditory times at 140 to 160 ms and reaction to touch at 155 ms. Woods and colleagues (2015) measured 1,469 adults aged 18 to 65 and found a mean simple reaction time of 231 ms, or 213 ms after correcting for hardware delays; a second sample of 189 adults aged 18 to 82 gave 238 ms, or about 220 ms after the same correction. A UK survey of 900 people aged about 56, using a nurse-run keypad device, found a mean of 358.2 ms (standard deviation 119.7) for simple reaction time and 727.8 ms for four-choice.
- Human Benchmark, median of online clicks, device lag included: 273 ms
- Woods et al. 2015, calibrated lab sample, ages 18 to 65: 213 ms
- Kosinski review, visual signal, college-age adults: 180 to 200 ms
- Deary, Der and Ford 2001, UK survey, age about 56, keypad device: 358 ms
The method moves the number more than the person does. Kosinski's review cites a study of NCAA football players who averaged 0.203 seconds when reaction was timed by a falling meter stick and 0.268 seconds when it was timed on a computer, in the same players.
How does reaction time change with age?
The best-controlled age data here come from Woods and colleagues. Latencies rose by 0.55 ms for each year of age and were unaffected by sex or education, so corrected times ran from about 200 ms in the youngest group to 222 ms in the oldest, up to age 65. Their detection-time measure averaged 131 ms and did not change with age, which led them to conclude that age-related slowing is due primarily to slowed motor output, not slower perception. Over 30 years the slope adds 16.5 ms, our arithmetic.
Der and Deary's 2006 analysis of 7,130 adults in the UK Health and Lifestyle Survey found that simple reaction time shows little slowing until around age 50, whereas choice reaction time, where the person must pick between responses, slows throughout adult life. It also found significant sex differences, most notably in the variability of choice reaction time. Our guide to the age at which intelligence peaks covers how other abilities move across the lifespan.
How strongly does reaction time track IQ?
Deary, Der and Ford (2001) tested 900 people, all about 56, and correlated reaction time with the Alice Heim 4 intelligence test: r = -.31 for simple reaction time and -.49 for four-choice. The sign is negative because shorter times go with higher scores. Der and Deary (2017) reported 2,196 people at ages 30, 50 and 69 (714, 813 and 669 people): simple reaction time correlated -.27, -.30 and -.32 with the same test, and four-choice -.44, -.47 and -.53. Squaring a correlation gives the share of variance the two measures have in common, which is 7% to 10% for simple reaction time and 19% to 28% for four-choice.
Reviews agree in outline. Sheppard and Vernon's 2008 review analysed 172 studies with 53,542 participants; Der and Deary report its summary correlation between overall reaction time and g as -.26 across 112 samples, ranging from -.22 for simple reaction time to -.4 for eight-choice. A 2016 meta-analysis of choice-reaction-time variability, covering 24 studies, 27 samples and 3,968 people, found correlations between -.18 and -.28. The g factor is the general ability these studies are measuring against.
Simple reaction time shares only about 7% to 10% of its variance with intelligence test scores: a real link, and far too weak to read an IQ from a click.
In IQ points, a correlation of -.3 means that a person whose simple reaction time is one standard deviation quicker than average is expected to score about 4.5 points above 100 (0.3 times 15), with individual scores still spread by about 14 points around that expectation. At -.49, one standard deviation quicker on four-choice reaction time is worth about 7 points. Our percentile calculator and guide to IQ z-scores show how a standard-deviation gap maps to a percentile. One caveat runs through these studies: the Alice Heim 4 is a time-limited test, as Der and Deary note, so part of the correlation is speed on both sides.
Why an online reaction test cannot estimate your IQ
There are three reasons. First, the correlation is too small: at 7% to 10% of variance, simple reaction time leaves about 90% of the difference in IQ unexplained. Second, the measurement is too noisy: Human Benchmark's own page says your computer could add 10 to 50 ms, and at the 0.55 ms per year slope in Woods and colleagues' data that is the size of 18 to 91 years of ageing, so device differences swamp person differences. Third, a single click test is one trial, while the studies above used calibrated equipment and many trials.
Were the Victorians faster, and so cleverer?
Francis Galton recorded visual simple reaction times of 181 to 189 ms in people aged 18 to 60, as Woods and colleagues summarise it, citing Johnson (1985). Silverman (2010) compared young adults' reaction times in 14 studies published since 1941 with Galton's and found that, with one exception, the newer studies obtained longer times. Woodley, te Nijenhuis and Murphy (2013) converted that slowing into an estimated decline of 1.16 IQ points per decade, or 13.35 IQ points since Victorian times.
The estimate was disputed at once. Dodonova and Dodonov (2013) concluded that any cross-study comparison of reaction times is uninformative because the methods differ, and argued that Galton recorded the shortest of three trials per person, which would make his figures faster than a mean. Woods and colleagues tested contemporary samples on calibrated equipment and found no evidence of slowed processing speed. Woodley and colleagues replied in 2015 that, even accepting the best-of-three correction for Galton, which lifts his figure to 208.5 ms for 3,418 people, UK means rose to 237.8 ms in Deary and Der's 2005 study of 543 people, about 22.8 ms slower per century, and maintained that the evidence for generational slowing remains quite compelling. Human Benchmark says its own recorded times have slowed slightly and attributes this almost certainly to changes in input and display technology. The question is unresolved, and it sits alongside the debate over whether raw IQ scores are still rising, covered in our guide to why IQ norms expire.
What is the fastest a human can react?
Sport supplies a rule, not a biological limit. World Athletics technical rules, effective 1 July 2026, say the start information system indicates a possible false start when the reaction time is less than 0.100 second, and that the equipment's evidence is a resource for officials making the decision. The text we read does not say why 100 ms was chosen. It sits below the 140 to 160 ms that Kosinski's review gives for an auditory signal, and it is a rule for officials, not a measurement of the limit of human speed.
Where would your own score land?
Want a score on the standard IQ scale, with its percentile? Take the IQ Metrics test.
Find your IQ score now! →Reaction time is one thread of processing speed, and processing speed is one of several abilities a full test samples. Vocabulary, for instance, keeps growing long after speed has peaked, as our guide to how many words the average person knows shows, and our guide to WAIS index scores shows how a Processing Speed Index is reported. For a timed test on the standard scale, try the timed IQ test or the full IQ Metrics test.
Common questions
What is the average human reaction time?
It depends on the stimulus and the device. One review gives 180 to 200 ms for a visual signal, a calibrated lab sample of adults aged 18 to 65 averaged 213 ms, and Human Benchmark's median is 273 ms, which includes device lag.
Does reaction time correlate with IQ?
Yes, modestly. In 900 UK adults aged about 56, simple reaction time correlated -.31 with an intelligence test and four-choice reaction time -.49; across ages 30 to 69 in 2,196 people, simple reaction time correlated -.27 to -.32.
How does reaction time change with age?
Slowly. A calibrated study of adults aged 18 to 65 found simple reaction time rose 0.55 ms per year, from about 200 ms in the youngest group to 222 ms in the oldest. A UK survey found little slowing until around 50 for simple reaction time and steady slowing for choice reaction time.
Can a reaction time test measure your IQ?
No. Simple reaction time shares only about 7% to 10% of its variance with IQ test scores, and an online test can add 10 to 50 ms of device lag, more than the slowing from decades of ageing.
Sources for this story
- Reaction time test and statistics pages — Human Benchmark
- Woods et al., Factors influencing the latency of simple reaction time (2015) — Frontiers in Human Neuroscience
- Deary, Der and Ford, Reaction times and intelligence differences: a population-based cohort study (2001) — Intelligence
- Der and Deary, The relationship between intelligence and reaction time varies with age (2017) — Intelligence
- Woodley, te Nijenhuis and Murphy, Were the Victorians cleverer than us? (2013), and the 2015 reply to Woods et al. — Intelligence; Frontiers in Human Neuroscience
- Dodonova and Dodonov, Is there any evidence of historical slowing of reaction time? (2013) — Intelligence
Corrections: spotted an error? Email corrections@iqmetrics.org and we will update this story and note the change here.
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