Reaction Science
Factors Affecting Reaction Time: 10 Things That Speed You Up or Slow You Down
Your reaction time isn't a fixed number. It shifts with the kind of signal, the decision involved, your age, sleep, attention, caffeine and even your mouse. Here are the factors that matter most.
- By ADR
- Updated
- 7 min read
Reaction time depends on three groups of factors: the task you're doing, the state you're in, and the equipment you're using. Here's how each one works.
Task factors
1. Type of signal
Studies comparing simple reactions generally find people respond faster to sounds than to lights. Compare yourself on the visual and audio tests.
2. Number of choices
Every extra possible response adds decision time. Hick's law describes this relationship, and it's why the choice test is slower than the simple test.
3. Predictability of timing
When you know exactly when a signal will come, you can anticipate it. Randomising the wait (the “foreperiod”) prevents this, which is why fair tests use random delays.
4. Signal strength and location
Bright, large, central signals are detected faster than faint or peripheral ones. Targets that appear in unpredictable places, as in the reflex test, add search and movement time.
Personal factors
5. Age
Large population studies find reaction times slow and become more variable across adulthood, with choice reactions affected more than simple ones. See reaction time by age.
6. Sleep and fatigue
Sleep loss is one of the most powerful influences. It increases average reaction time and, especially, the number of lapses. Read more in reaction time and sleep.
7. Attention and distraction
Notifications, conversation or a busy mind cause slow outliers. These show up as a higher standard deviation in your results.
8. Caffeine and other substances
Moderate caffeine tends to improve alertness and reaction time, particularly when tired. Alcohol and sedating medications slow reactions. See caffeine and reaction time.
9. Practice
Familiarity with a task reduces errors and variability. See our training guide.
Equipment factors
10. Hardware and software latency
In any online test, your display, input device, operating system and browser all add delay. A 60 Hz screen alone can add up to ~16.7 ms. Read mouse latency and reaction time for details.
| Factor | Typical direction | Can you change it? |
|---|---|---|
| Sound vs. light | Sound usually faster | Depends on the task |
| More choices | Slower | Practice helps |
| Sleep loss | Slower, more lapses | Yes |
| Age | Gradually slower | Partly (fitness, practice) |
| Moderate caffeine | Often faster | Yes, with care |
| Device latency | Slower measured time | Yes |
Frequently asked questions
What is the biggest factor affecting reaction time?
Does gender affect reaction time?
Why does my reaction time vary from day to day?
Sources
- Jain A, Bansal R, Kumar A, Singh KD. A comparative study of visual and auditory reaction times on the basis of gender and physical activity levels of medical first year students. Int J Appl Basic Med Res. 2015;5(2):124–127.
- Hick WE. On the rate of gain of information. Q J Exp Psychol. 1952;4(1):11–26.
- Niemi P, Näätänen R. Foreperiod and simple reaction time. Psychol Bull. 1981;89(1):133–162.
- Der G, Deary IJ. Age and sex differences in reaction time in adulthood: results from the United Kingdom Health and Lifestyle Survey. Psychol Aging. 2006;21(1):62–73.
- Lim J, Dinges DF. A meta-analysis of the impact of short-term sleep deprivation on cognitive variables. Psychol Bull. 2010;136(3):375–389.
- Woods DL, Wyma JM, Yund EW, Herron TJ, Reed B. Factors influencing the latency of simple reaction time. Front Hum Neurosci. 2015;9:131.
About the author: ADR
ADR is a PUBG player who built ReactionTestTime while trying to react faster in close-range fights. ADR writes and reviews every guide and test on the site and checks each claim against published research.