Stroop Test — Name the Ink Colour, Not the Word
Frequently Asked Questions
What is the Stroop effect?
The Stroop effect, first described by John Ridley Stroop in 1935, is the delay that happens when the meaning of a word conflicts with the colour it is printed in. Reading is so automatic that your brain must actively suppress the word to name the ink colour — that suppression takes measurable time.
What does the Stroop test measure?
It measures selective attention and inhibitory control — your ability to suppress an automatic response (reading) in favour of a deliberate one (naming the ink colour). Your interference score is the difference between your speed on matching and mismatching trials.
What is a good Stroop test score?
Accuracy of 27 or more out of 30 with an average response under 900 ms is a strong performance. Most people respond noticeably slower on mismatching trials — an interference gap of under 150 ms shows excellent inhibitory control.
The science behind the Stroop effect
The Stroop test asks you to name the colour a word is printed in, while ignoring the word itself. When the word "red" is printed in blue ink, your brain wants to read the word rather than name the colour, and overcoming that conflict takes extra effort and time. This famous effect measures cognitive control and selective attention — your ability to focus on one thing while suppressing a stronger, automatic response.
What your results tell you
- A small gap between matching and conflicting trials shows strong attentional control.
- Fatigue and stress widen the gap — the effect is sensitive to your mental state.
- The skill it taps, inhibition, supports focus, self-control and decision-making.
- Practice and full concentration both reduce the Stroop slowdown.