Stroop Test
In the Diem app this game is Color Clash.
Tap the ink color, not the word.
This is a game, not a medical or psychological test.
How the Stroop test works
Each word on the card is a color name, written in an ink. Tap the key for the ink and ignore what the word says. When BLUE is written in blue ink, the two agree: a matching word. When BLUE is written in orange ink, they clash, and your eyes have read the word before you can stop them. That small tug toward the wrong key is the Stroop effect.
A run is 30 words in four inks: blue, orange, pink and black. About four in ten match their ink. The keys stay in place for the whole run; on a keyboard, 1 to 4 press them. A wrong key rings the right one for a moment, then a new word comes, so every run ends with 30 right answers. The words come from the generator of Diem's Color Clash.
What your score means
Your main number is your average time per right answer, in milliseconds (ms), from the moment a word appears to your key press. Beside it is your accuracy: right answers out of every key you pressed.
The result also splits your time into matching and clashing words. The gap between them is your Stroop effect for that run; usually the clashing words take longer.
You won't see how you compare with other people: there is no fair average for a game played on so many different screens and keyboards. The number to beat is your own. Your best counts runs with 90% or more right, so guessing never sets it, and a line of your last 10 runs sits under each result.
Tips for a better run
- Look over the keys before you press Start. They don't move during a run.
- On a phone, use both thumbs. On a computer, rest four fingers on 1 to 4.
- Go for accuracy first. A wrong key holds the game for 0.7 seconds and costs accuracy.
- Play where nobody will interrupt you. If you leave the page, the run pauses and the word starts again when you go on.
Color-blind shapes
Every ink has its own texture, on the bar under the word and on its key: blue solid, orange striped, pink dotted, black an outline. Turn on Color-blind shapes under the keys and each ink also wears a shape on its bar and key: blue ●, orange ■, pink ▲, black ◆. The words and inks stay the same. The card and keys are white in light and dark mode, so every ink keeps its contrast, and the test never uses red or green.
Where the Stroop test comes from
The test is named after J. Ridley Stroop, who described the effect in 1935 in “Studies of interference in serial verbal reactions” (Journal of Experimental Psychology, 18, 643–662, doi:10.1037/h0054651). In his second experiment, naming the inks of 100 clashing color words took 110.3 seconds on average, against 63.3 seconds for the colors of 100 squares: 74 percent longer. The paper is reprinted at Classics in the History of Psychology. The version here is shorter and timed word by word.
FAQ
What is the Stroop effect?
The delay you feel when a word and its ink disagree: naming the ink of BLUE written in orange takes longer than naming the ink of a word that matches, because the word is read before you can stop it.
How does the Stroop test work?
You see color words in colored ink and answer the ink, not the word. Here a run is 30 words in four inks; tap the ink's key or press 1 to 4. Each answer is timed from the moment its word appears.
What does the Stroop test measure?
In this game: how fast you name the ink, how often you are right, and how much longer clashing words take you. Researchers use other versions in their studies; this page is a game for fun and says nothing about your health.
Why is the Stroop test so hard?
Reading comes quicker than naming a color. On a clashing word the meaning arrives first and pulls you toward the wrong key, and you have to hold it back.
How is the Stroop test scored?
Versions differ. Here your score is the average time of your right answers in milliseconds, with your accuracy beside it, and your time on matching against clashing words.
Do I need an account to play?
No. Your best and your last 10 scores are kept in this browser only.