The Stroop Test

I came across this test recently. If you need to discover a Russian under-cover agent you can show them color words (words like red, green, blue) colored in a different color.

Like so:

Green Blue Purple

If you comprehend the words, you perform poorly at this test than otherwise.

The Stroop test on Wikipedia.

Per Intellectum, Vis
(c) Shriphani Palakodety 2013-2016