In other words, the “trick” was revealed in advance.
Would you like to guess the percentage of the participants in the second group who solved the puzzle correctly?
Indeed, the concept enjoyed such strong popularity and intuitive appeal that no one bothered to check the facts.
Yet participants’ performance was not improved even when they were given specific instructions to do so.
That is, direct and explicit instructions to think outside the box did not help.
Even though they weren’t instructed to restrain themselves from considering such a solution, they were unable to “see” the white space beyond the square’s boundaries.
Only 20 percent managed to break out of the illusory confinement and continue their lines in the white space surrounding the dots.