Experiencing The Stroop Effect With a Ruby CLI

You’ve probably seen these weird lists of color words before. Words whose text color does not match their content. Maybe you’ve even tried to read the text colors out loud quickly and have struggled to do so?

These lists are part of psychological tests to demonstrate the so-called Stroop effect. It is named after the American psychologist John Ridley Stroop, who first published the effect in English in 1935.

Wikipedia tells us:

“The Stroop effect is the delay in reaction time between congruent and incongruent stimuli.”

But what does that actually mean? 🤔

I built a tiny command line interface with Ruby — just because it was fun and so that you can experience the Stroop effect yourself. You can install and run it with:

gem install stroop
stroop

Congruent? Incongruent?

A Stroop tests consists of a small task, like reading color words. This task can be done with different kind of stimuli, namely: neutral, congruent, and incongruent.

Let’s take a list of color words with a neutral stimulus, which means that all words are written in the same text color: