How To Catch A Russian Spy
One interesting way in which a person’s (native) language reveals itself is the so-called Stroop effect, which can be illustrated with the image below (from Wikipedia). If you look at the first set of words, it’s not that difficult to say aloud the color of the letters that spell out each word: green, red, blue, purple, etc. But the task appears to be much harder with the second set of words. For most people it takes longer to complete the task with the second set of words, because the words spell out a different color than the actual color of the font used.
But this difference in time needed for the two sets of words appears only if the task is performed by an English-speaker: someone who cannot read/understand the words themselves will not be slowed down by their meaning. In a similar fashion, if you look at the picture below (where the second set of words is in Russian), you will be likewise slowed down on the second set, but only if you speak Russian.
According to Roy F. Baumeister and John Tierney’s book called Willpower: Rediscovering the Greatest Human Strength,
“the Stroop task became a tool for American intelligence officials during the cold war. A covert agent could claim not to speak Russian, but he’d take longer to answer correctly when looking at Russian words for colors.”
According to the Wikipedia, the Stroop effect can also be used to diagnose certain psychological issues:
“depressed participants will be slower to say the color of depressing words rather than non-depressing words. Non-clinical subjects have also been shown to name the color of an emotional word (e.g., ‘war’, ‘cancer’, ‘kill’) slower than naming the color of a neutral word (e.g., ‘clock’, ‘lift’, ‘windy’).”
And if the Stroop-effect doesn’t work for some reason, you can always try to catch a Russian spy by asking him/her to do a simple arithmetic problem (people tend to do calculations in their native tongue), or to count “on the fingers” (unlike Americans, Russians count by bending fingers in, starting with the little finger).
(The picture below is a famous Soviet WWII poster which reads: “Do not blabber on the phone, a big-mouth is a find for a spy”)