Stroop effect

In psychology, the Stroop effect is the delay in reaction time between neutral and incongruent stimuli.

The effect has been used to create a psychological test (the Stroop test) that is widely used in clinical practice and investigation.^[1]

A basic task that demonstrates this effect occurs when there is an incongruent mismatch between the word for a color (e.g., blue, green, or red) and the font color it is printed in (e.g., the word red printed in a blue font). Typically, when a person is asked to name the font color for each word in a series of words, they take longer and are more prone to errors when words for colors are printed in incongruous font colors (e.g., it generally takes longer to say "blue" in response to the word red in a blue font, than in response to a neutral word of the same length in a blue font, like kid).

The effect is named after John Ridley Stroop, who first published the effect in English in 1935.^[2] The effect had previously been published in Germany in 1929 by other authors.^[3][4][5] The original paper by Stroop has been one of the most cited papers in the history of experimental psychology, leading to more than 700 Stroop-related articles in literature.^[5]