What is the difference between reaction time and a reflex?
These terms are often used interchangeably but they describe fundamentally different biological processes. A reflex bypasses the brain; a reaction requires conscious brain processing.
| Feature | Reflex | Reaction time |
|---|---|---|
| Neural pathway | Spinal cord loop | Brain involved |
| Speed | ~15–50ms | ~150–300ms |
| Conscious control | None (involuntary) | Yes (voluntary) |
| Can be trained? | Not significantly | Yes |
| Example | Knee-jerk reflex | Clicking when screen turns green |
When a cricket batsman "reacts" to a 90mph delivery, they are not purely reacting — they are using anticipation and pattern recognition. Their brain processes the bowler's release point and arm speed before the ball leaves the hand. This is why expert athletes appear superhuman: they don't have faster pure reflexes — they have better predictive models.
Test it yourself
Free, no account needed — results in 60 seconds.
Quick Answer
A reflex is an involuntary spinal-cord response that bypasses the brain (e.g. knee-jerk). Reaction time involves conscious brain processing. Reflexes are faster (~20ms) but not controllable.
Related Test
More Questions
Go deeper
The Science Page
Peer-reviewed research and full methodology behind every test.