Because the solution is, in hindsight, deceptively simple, clients tended to admit they should have thought of it themselves.

Because they hadn’t, they were obviously not as creative or smart as they had previously thought, and needed to call in creative experts. The nine-dot puzzle and the phrase “thinking outside the box” became metaphors for creativity and spread like wildfire in marketing, management, psychology, the creative arts, engineering, and personal improvement circles.

Today many people are familiar with this puzzle and its solution.No one, that is, before two different research teams—Clarke Burnham with Kenneth Davis, and Joseph Alba with Robert Weisberg—ran another experiment using the same puzzle but a different research procedure.Both teams followed the same protocol of dividing participants into two groups.The first group was given the same instructions as the participants in Guilford’s experiment.The second group was told that the solution required the lines to be drawn outside the imaginary box bordering the dot array.It was an appealing and apparently convincing message.Indeed, the concept enjoyed such strong popularity and intuitive appeal that no one bothered to check the facts.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.Most people assume that 60 percent to 90 percent of the group given the clue would solve the puzzle easily. What’s more, in statistical terms, this 5 percent improvement over the subjects of Guilford’s original study is insignificant.In other words, the difference could easily be due to what statisticians call sampling error.For example, there have been some theories such as those of Schopenhauer (see his remarks about Genius) and Freud (see his remarks about Sublimation) that propose creativity is something more like a capacity provided by nature rather than one acquired or learned from the environment.Rather than disproving the myth, in other words, the experiment might instead offer evidence that creativity is an ability that one is born with, or born lacking, hence why information from the environment didn't impact the results at all.The symmetry, the beautiful simplicity of the solution, and the fact that 80 percent of the participants were effectively blinded by the boundaries of the square led Guilford and the readers of his books to leap to the sweeping conclusion that creativity requires you to go outside the box.The idea went viral (via 1970s-era media and word of mouth, of course).