Let’s look a little more closely at these surprising results.
Solving this problem requires people to literally think outside the box.
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.
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.
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.