The Stroop Effect in Psychology: Definition, Test & Experiment

An error occurred trying to load this video.

Try refreshing the page, or contact customer support.

Coming up next: Sensory Cortex: Definition & Function

You're on a roll. Keep up the good work!

Take Quiz Watch Next Lesson
Your next lesson will play in 10 seconds
  • 0:00 Who Was John Stroop?
  • 0:20 The Stroop Effect
  • 1:18 Trying The Stroop…
  • 2:10 The Stroop Experiment
  • 2:52 Underlying Psychology
  • 4:05 Lesson Summary
Save Save Save

Want to watch this again later?

Log in or sign up to add this lesson to a Custom Course.

Log in or Sign up

Speed Speed Audio mode

Recommended Lessons and Courses for You

Lesson Transcript
Instructor: Laura Gray

Laura has taught at the secondary and tertiary levels for 20+ years and has a Ph.D. in Instructional Design for Online Learning.

This lesson discusses the Stroop Effect. You will learn about the man and original experiment behind it, try it yourself, study the underlying psychology, and also see what we know today.

Who Was John Stroop?

John Ridley Stroop was an American psychologist who studied reaction times in individuals as part of his work. In 1929, he created what would later be called the Stroop Test. This short and simple test could easily show how quick someone's reaction time was, and in 1935, he was able to publish his findings.

The Stroop Effect

So... what's so great about the effect? Well, Stroop didn't know it at the time, but his test and the paper that accompanied it would go on to become one of the most well-known, most cited papers in the history of experimental and cognitive psychology. The Stroop Test (and the resulting Stroop Effect, which is the name given to the experience of an individual who takes the test) shows that our brains process seemingly conflicting information differently than they process more straightforward information.

In other words, when we see the word 'red' written in the color red, we process the color of the word more quickly than if the word 'red' were written in green and we were expected to just name the color rather than the word. Does that make sense? Essentially, the Stroop Effect studies how interference can affect the way our brains process information and complete tasks.

Trying The Stroop Effect Yourself

Here is an example of a basic Stroop Test. Take a look at it. Seems easy enough, right? All you have to do is say color the word is printed in rather than reading the word itself. Still think the task seems ridiculously easy? Try it!

Typical Stroop Test

It's a little harder than you thought, isn't it? That's what Stroop was trying to show. He recognized that processing times slow down when people take this test because our brains take a little more time to assimilate the information. Even though Stroop discovered all of this almost 100 years ago, the Stroop Test is still used today, generally by cognitive psychologists. It is not uncommon for people who have had damage to portions of their brains to be given this test to demonstrate how quick their processing speed is in certain areas of the brain. And, of course, the Stroop Test is also given just for fun in many, many college psychology courses.

The Stroop Experiment

Stroop's original experiment had three elements to it:

  1. First, there was just a list of color words printed in black.
  2. Second, there was the element that is pictured earlier. Stroop could measure a difference in reaction time by having people initially just read the words in black and then try to say the actual colors of the words.
  3. The third element was a long row of blocks of different colors--no words at all. Evidently, it is very easy for people to just name the colors of the blocks without any words at all being present.

By comparing performance on these three tasks, Stroop could make inferences about the individual's processing speed and ability.

To unlock this lesson you must be a Member.
Create your account

Register to view this lesson

Are you a student or a teacher?

Unlock Your Education

See for yourself why 30 million people use

Become a member and start learning now.
Become a Member  Back
What teachers are saying about
Try it risk-free for 30 days

Earning College Credit

Did you know… We have over 200 college courses that prepare you to earn credit by exam that is accepted by over 1,500 colleges and universities. You can test out of the first two years of college and save thousands off your degree. Anyone can earn credit-by-exam regardless of age or education level.

To learn more, visit our Earning Credit Page

Transferring credit to the school of your choice

Not sure what college you want to attend yet? has thousands of articles about every imaginable degree, area of study and career path that can help you find the school that's right for you.

Create an account to start this course today
Try it risk-free for 30 days!
Create an account