Stroop Test
Tap the color of the ink, not what the word says. Your time when the word lies is the score; the lag under it is what the lie cost.
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Bar widths show roughly how many people land in each band on the provisional curve. The ranked number is your time on lying words, which only gets worse when you play worse; the lag under it says how much of it was the lie. Sixteen words of each kind, shuffled; a wrong answer repeats its kind.
What moves it
Reading is automatic. You cannot look at a word you know and not read it. Naming the ink has to win a race against a reader that started first, and the lag is what winning costs.
The language. The interference comes from reading, so a word in a language you read fluently lies harder than one you have to decode. Take the test in your own language; the curve does not split by it, everyone plays in one pool.
Your hardware, in the time but not in the lag. A slow screen or a laggy touchscreen adds the same milliseconds to every word, matching or lying. Your time carries them, like the reaction-time test does; the lag under it subtracts them out, which is why it travels between devices better than any raw time on this site.
What this measures
The Stroop effect is one of the most replicated results in psychology. Since 1935 it has shown the same thing in every literate population tested: naming the ink color of a word slows down when the word spells a different color. Reading in a language you know is automatic, it cannot be switched off, so the correct answer has to overtake a reader that started first. The delay is called interference, and it is what this page measures.
Thirty-two words, sixteen where ink and word agree and sixteen where the word lies, shuffled, with three practice words to warm the mapping up. Answers land on D F J K or the four buttons, each labeled with its color's name so hue is never the only cue. The score is your average time on lying words, the number that cannot be gamed by slow-walking the easy ones; the lag under it is lying minus matching, your interference in milliseconds.
The words come in your language, picked by the pill under the field, because the interference is a reading effect: a word you have to decode slowly lies weakly. The lag is also the number here that travels best between devices, since your hardware's milliseconds sit in both averages and cancel in the subtraction. The curve and its pool are on the Method page.
Questions people ask
John Ridley Stroop showed it in 1935: people name the ink color of a word much more slowly when the word is the name of a different color. Reading is so practiced that it runs on its own, and holding it back takes time. That time is your lag.
Because a difference can be gamed: answer the matching words slowly and the lag shrinks, down to nothing, with no visible foul. Your time on lying words only gets worse when you play worse, so it is the number that ranks you. The lag is still here, one line down: it is the part the lie added, and the interesting one to compare across days.
On the provisional curve, 750 ms a word is the middle and under 650 is quick; about 110 ms of a typical time is the lie. The curve is an assumption, not a measurement: lab four-choice reaction times plus a browser's lag plus what button-press Stroop tasks report, with a guessed spread. The site switches to its own distribution as runs accumulate; everyone plays in one pool, whatever the words' language.
On a noisy run, yes: sixteen words of each kind is a small sample, and a few slow matching ones lift that average above the lying one. A negative lag is not immunity to words, it is a wobbly pair of averages, and it does not change your score. The three practice words and the 1.5 second lapse rule exist to keep the wobble small.
Not here. Research and clinical batteries use Stroop tasks to study attention and executive function, but they do it with normed instruments, controlled conditions and a professional in the room. A browser game with your monitor in the loop is none of those things, and does not try to be. The lag speaks about this run of yours: sleep, practice and the words' language all move it. A mirror, not a chart note.
It starts as an assumption worth 300 runs, shaped from published norms, and every run played here adds one to it, everyone in one pool. The Method page says which norms, how the percentile is read, and how many runs this test has measured so far.