Stroop: Inhibition
Ink colour, not the word meaning
About this trainer
Words for colours are printed in a mismatched ink — the word "RED" in blue — and you must name the ink, not read the word. Naming the colour means overriding the automatic urge to read.
What it develops
Inhibitory control — suppressing a fast, automatic response in favour of a slower, goal-relevant one — plus selective attention and processing speed.
History
One of psychology's most-cited experiments. It has been adapted thousands of times since the 1930s and is a standard clinical and research measure of executive function.
Who created it — and when
John Ridley Stroop, who described the effect in his 1935 paper "Studies of Interference in Serial Verbal Reactions".
How to train
Go for accuracy first, then speed. Track your interference cost — the extra time on mismatched (incongruent) trials versus matched ones — rather than raw reaction time. Keep blocks short so fatigue does not inflate errors.
How long to practise
A few minutes of short blocks, a handful of times a week. Your interference cost typically shrinks over the first sessions as the override becomes more efficient, then levels off.
Evidence base
The effect itself is rock-solid and reproduces in almost everyone. Training reliably shrinks your own interference on the task; whether that carries over to everyday self-control is far less certain, so train it for the specific skill, not a broad willpower upgrade.
Recommendations
Use it to sharpen accurate, fast overriding under conflict. Stop the moment errors climb — sloppy speed is not the skill.
FAQ
What is the Stroop effect?
The slowdown when you name the ink colour of a colour word that spells a different colour — reading interferes with naming.
What does it measure?
Inhibitory control and selective attention, a core part of executive function.
Can I train it?
You can lower your own interference cost with practice; broad transfer to real-life self-control is not well established.
Variants
Classic colour-word; emotional Stroop (emotional words instead of colours); numerical and spatial Stroop; and reverse versions where you read the word and ignore the ink.