The Stroop Effect was first discovered by Erich Rudolf Jaensch in 1929.
So why is it called the “Stroop effect”?
Jaensch published his insight about the Stroop effect in a book called “Grundformen menschlichen Seins” in Berlin. The title means “Basic forms of human existence,” but as you can guess it was written entirely in German.
When John Ridley Stroop conducted his experiments and published the results in 1935, Jaensch’s book had not yet been translated into English or published in English-speaking countries. Because the majority of science publications at this time were written and read in English, the word spread on Stroop’s result very quickly, and soon his name was inseparable from the experimental task and the results that it proved.
Nobody believes that Stroop “stole” the idea from Jaensch: it’s fairly obvious that both people came up with the result independently.
But there is a lesson to be learned from this story: sometimes, being the first to discover something isn’t enough. You need to get people to know that you made the discovery, if you want to get the credit that you deserve.