Welcome back to HRW’s Behavioral Summer Camp: where, throughout August, our internal team of behavioral scientists (known as HRW Shift) taught you about some of the larger principles that drive behavior.

For our final activity, we return to three quick questions. Have a look at the questions below to get your brain juices flowing, then scroll down for the solution.

We hope you enjoy.

The HRW Shift team


Question 1

Read out loud the font color that each word is written in:





Question 2

How many times is each word written?


Question 3

What is the number with the largest numerical value?


As summer holidays and vacations wrap up and busy schedules resume, we wanted to keep the final lesson simple and relevant to the way we mentally process competing priorities through our exploration of ‘The Stroop Effect’.

‘The Stroop Effect’ was coined by the Psychologist John Ridley Stroop in 1935 to describe the pause which occurs when a person attempts to process two competing pieces of information at the same time. The Stroop Test replicated a German study and aimed to validate the hypothesis that naming the font color of a word is quickest and easiest if the word’s meaning matches its presentation, or as Stroop called the match ‘congruent’ words. For example, he hypothesized we can most quickly identify the red font color when the word written is also ‘red’, such as this congruent example:





To prove his hypothesis, he tested the response rates of congruent words compared to ‘neutral’ and ‘incongruent’ words. A ‘neutral’ word is meant to be completely random and have no meaning attached to it. Stroop expected however, that even if a word held no meaning, it would be impossible for our brains not to read a written word, therefore slowing down the response to the question of font color. The results were consistent with this belief and showed that when presented with neutral examples, individual’s average response time increased. Take the example below, our brains require an additional moment as they automatically recognize, read, and process the neutral word ‘car’ before it can focus on the task of correctly identifying the blue font color:



Going further, Stroop included ‘incongruent’ words, meaning the word’s definition was in direct conflict with the task of naming the font color. He anticipated and found that these examples would take the most time, because they require additional cognitive effort, as the respondent must override the first piece of information they automatically read, to answer the question correctly. In the incongruent example below, it is difficult to ignore the written word “green” as we try to focus on the orange font color, as spontaneous associations of another color interfere with the task at hand:





The Stroop Test experiment was one of the first widely accepted experimental psychology studies. The simple exercise has had a major impact on clinical, neurological assessments, cognitive psychology practices, and pop culture brain game apps. This simple task has been cited in nearly 15,000 experimental reviews and studies, and led to more than 700 Stroop-related articles in academic literature. Variations on the experiment include testing the effect of words that are visually distorted, emotionally charged, spatially placed, and numerical (such as the final examples in this week’s activity, which play with how many times a word is written versus the numerical value written, and font size versus the value of a number). The Stroop Effect method was also utilized on an episode of MythBusters, where they disproved the rumor that individuals are cognitively impaired by having an attractive member of the opposite sex in the room.

Please contact our team of behavioral experts, HRW Shift, if you would like to find out more.


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