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Under the Behavior

Stroop test online: say the ink, not the word

In Stroop's 1935 study, naming the ink of clashing words took 74% longer than naming colour squares. Stroop, 1935

Stroop test

Tap the colour each word is printed in. First 12 cards where the word and the ink match, then 12 where they clash. The page times both rounds.

This test runs on JavaScript, in your browser only. With it turned off, the steps and the study's numbers are below.

Runs in your browser. Nothing you tap is sent or saved.

How it works

  1. 1Read the rule

    Tap the colour of the ink, not the word.

  2. 2Round one

    Twelve cards where the word and the ink match.

  3. 3Round two

    Twelve cards where they clash. The page times both rounds.

What Stroop found in 1935

Time for 100 items in Stroop's Experiment 2
  • Naming colour squares63.3 s
  • Naming the ink of clashing words110.3 s
Stroop, 1935
74%

longer to name the ink of clashing words than to name colour squares. The time for 100 items went from 63.3 to 110.3 seconds.

Experiment 2 · Stroop, 1935
5.6%

longer to read the words in clashing ink than in black, only 2.3 seconds per 100 words. Stroop called that gap not reliable.

Experiment 1 · Stroop, 1935
More from the paper
[The difference] may be satisfactorily accounted for by the difference in training in the two activities.
Quoted from Stroop, Journal of Experimental Psychology, 1935

In other words, we have had far more practice reading words than naming colours. By 1991, a review counted more than 700 articles on the effect.

Try it again, harder

Hard modeTwice as many clashing cards, and the rule switches between the ink and the word as you go.Play

Questions

Is this a test for ADHD or anything else?

No. This page does not test for anything. It shows how the task works, and what Stroop measured in 1935.

Is anything I tap saved?

No. The test runs in your browser and sends nothing anywhere.

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Sources (2)

  1. Stroop, J. R. (1935). Studies of interference in serial verbal reactions. Journal of Experimental Psychology, 18(6), 643 to 662. doi.org/10.1037/h0054651
  2. MacLeod, C. M. (1991). Half a century of research on the Stroop effect: An integrative review. Psychological Bulletin, 109(2), 163 to 203. doi.org/10.1037/0033-2909.109.2.163

Our card list is our own, drawn after Stroop 1935. His colours were red, blue, green, brown and purple.