Reaction Time Test

The average human reaction time to a visual stimulus is about 250 milliseconds, a quarter of a second. That is the time it takes your brain to perceive the stimulus, process it, decide on a response and send the signal to your muscles. Age, fatigue, caffeine and practice all affect it. Young adults (18 to 25) are usually fastest, and reaction time slows gradually with age.

Professional esports players and athletes often train to reach 150 to 200 ms. Genetics set your baseline, but consistent practice can improve reaction time by 10 to 20% over several weeks.

Research in cognitive psychology has found a modest but consistent correlation between reaction time and general intelligence (the g factor). People with higher IQ scores tend to have slightly faster and more consistent reaction times. This is thought to reflect neural efficiency: faster signal transmission helps both quick reactions and cognitive performance.

Reaction time alone is still a poor predictor of intelligence. The correlation (r = -0.2 to -0.4) leaves a lot of overlap between fast and slow responders at every IQ level. A reaction time test measures processing speed, one of many abilities that make up overall intelligence.

Several evidence-based habits help. Get 7 to 9 hours of good sleep, because sleep deprivation markedly slows reactions. Regular aerobic exercise improves processing speed, and action video games can train visual attention and response speed.

Mindfulness meditation can sharpen attentional focus. Stay hydrated and eat a balanced diet with omega-3 fatty acids and antioxidants. Moderate caffeine (1 to 2 cups of coffee) can briefly speed you up, but too much causes jitteriness and can slow your responses.