The Future of Our Illusions

Sometimes, the reason you don't discuss the gorilla in the room is that you never notice it's there. That, literally, is what cognitive neuroscientists Christopher Chabris and Daniel Simons discovered at Harvard a decade ago, using an ingeniously simple approach.
First, they created a short film of students passing a basketball to one another. The clip was largely unremarkable except for the fact that, about halfway though, an actor in a gorilla suit sauntered through the group of basketball-tossers, pounded his chest and then continued walking. Total screen time: nine seconds.
The mini-movie was then shown to experiment-subjects, who were told to keep track of the total number of passes that they observed during the minute-long film. Distracted by their task, about half the viewers reported never seeing the gorilla. They were shocked to learn of its existence.
In "The Invisible Gorilla," Messrs. Chabris and Simons argue that the illusion of attention (as they categorize the gorilla demonstration) is but one of many"everyday illusions" that obscure our perceptions and cause us to place.

As a thoughtful introduction to a captivating discipline, the book succeeds wonderfully. And there may be something usefully chastening about its message: that we cannot always trust what seems most certain to us, especially when our judgments are aimed at ourselves. As the authors suggest, a state of illusion seems to be part of our neurological make-up. It might be a good idea—one might think—for us to cultivate a routine skepticism toward all sorts of supposed certainties.