Description of the Stroop Color and Word Test

The Stroop Color and Word Test is widely used in school and neuropsychological situations. It measures a person's attention, executive functions, and inhibitory behavioral control.
Description of the Stroop Color and Word Test
Valeria Sabater

Written and verified by the psychologist Valeria Sabater.

Last update: 15 November, 2021

The Stroop Color and Word Test has been used since 1935. It measures people’s attentional control using an interference system. For example, one of the challenges might be to read a series of color names written in a different shade from the one they designate. It seems simple but is actually difficult in practice.

This is one of the most common and popular psychological tests. It’s quite old and largely studied. In fact, it was J.M. Cattell who realized the relevance of this concept in 1886: human beings discriminate colors before words. The reading process is more complex and requires a higher level of attention and concentration.

However, it was experimental psychologist John Ridley Stroop who delved much deeper into the relationship between cognition and inference. He coined the term “Stroop effect”. This idea summarizes the difficulty people have when reading the word “green” written in red. Something like this is quite difficult and doctors use it to evaluate neuropsychological problems.

A brown eye.

What does the Stroop Color and Word Test measure?

This test is an attentional test with which to evaluate the ability of a person to classify information from the environment and to react selectively to that information.

  • It’s a common instrument in neuropsychological practice to identify students, hyperactive or not, with attention deficits. It’s also helpful in the evaluation of people with dementia and brain damage and can even help measure how stress affects a person’s attentional processes.
  • Similarly, studies such as one conducted at the University of Minnesota reveal the brain area linked to the Stroop task is the anterior cingulate cortex and the dorsolateral prefrontal cortex.
  • Finally, these structures concentrate processes related to memory, attention, reading, and color discrimination.

How to apply the Stroop Color and Word Test

This test is quite simple to use and apply.

  • Professionals apply it individually.
  • It takes less than 15 minutes.
  • In addition, professionals apply it to people who can read, so that, on average, they use it in people between the ages of seven and 70.
  • The test consists of three sheets containing 100 items.
  • In addition, the purpose is for the subject to be able to reduce their impulses; that first automatic response that arises when looking at the pictures. The most common mistake is to say “green” when a different word is written in this color.
  • Finally, the test measures selective attention as well as processing speed.

The three phases of the Stroop Color and Word Test

This test consists of three specific yet simple phases. There are three different sheets and five columns in each of them that contain three elements. The subject must do the following.

Read in the first phase

The first task is the simplest and intended to break the ice. At the same time, it introduces the person to the test. To do so, the person gets a list of three words repeated in an arbitrary manner: red, blue, and green. The difficulty lies in the fact that these words are all written in black. Furthermore, the objective is to not make mistakes while reading them quickly.

The second phase is about accuracy in color vs. figure

In this phase, the person gets a second card with a series of figures in different colors. The objective is simple, although not without difficulty for those who aren’t paying attention. The person must first identify the color of each figure. Then, they must state what symbol or figure it is (a square, cross, star, etc.).

The third phase is about inference

This is the best known. There’s a set of words in different colors in this card — red, blue, and green. The purpose here is for the person to read each word quickly and without making mistakes. The difficulty, of course, lies in the fact that these words are names of colors and the color of the type with which they’re written doesn’t correspond to their actual meaning.

How to evaluate the Stroop Color and Word Test

There are two variables to evaluate this test: the number of hits and the response time. Both factors are important because some people might spend an excessive amount of time performing a single task. Thus, the professional must take all the data into account, including the difficulty in understanding the instructions (something common in cases of dementia or drug abuse).

On average, the Stroop Color and Word Test is particularly useful for assessing executive functions in patients with Alzheimer’s disease, schizophrenia, and Huntington’s chorea. This is because damage to the anterior cingulate cortex and prefrontal cortex is usually progressive and noticeable. As you can see, this instrument is as simple as it’s useful. In fact, it’s still valid despite its age but remarkably effective, above all.


All cited sources were thoroughly reviewed by our team to ensure their quality, reliability, currency, and validity. The bibliography of this article was considered reliable and of academic or scientific accuracy.


  • Golden, C.J. (2005). Test de colores y palabras (Stroop). Madrid: TEA Ediciones.
  • Stroop, John Ridley (1935). “Estudios de interferencia en reacciones verbales seriadas” . Revista de psicología experimental . 18 (6): 643–662. Doi : 10.1037
  • Jensen AR, Rohwer WD (1966). “La prueba de color-palabra Stroop: una revisión”. Acta Psychologica . 25 (1): 36–93. doi : 10.1016 / 0001-6918 (66) 90004-7 . PMID 5328883 .

This text is provided for informational purposes only and does not replace consultation with a professional. If in doubt, consult your specialist.