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.
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.
It's an interesting experiment, but the author's conclusion cannot possibly follow from the results of it.
your conclusion: that the second experiment disproves the theory that thinking outside the box is useful in solving problems, is itself a fallacy.
Let’s look a little more closely at these surprising results.
Solving this problem requires people to literally think outside the box.
There seemed to be no end to the insights that could be offered under the banner of thinking outside the box.
Speakers, trainers, training program developers, organizational consultants, and university professors all had much to say about the vast benefits of outside-the-box thinking.
They are much more common than you probably think.*From Inside the Box: A Proven System of Creativity for Breakthrough Results Copyright 2014 Drew Boyd There are many theories of creativity.