Stroop effect

In psychology, the Stroop effect is the delay in reaction time between congruent 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 a mismatch between the name of a color (e.g., "blue", "green", or "red") and the color it is printed in (i.e., the word "red" printed in blue ink instead of red ink, thus red). When asked to name the color of the word it takes longer and is more prone to errors when the color of the ink does not match the name of the color.

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]