commentary20121025013716.mp3 In 1997 two psychologists designed an experiment in which they directed a group of volunteers to view a film that lasted less than a minute in which people assembled in a circle pass a basketball to one another. The viewers were asked to count the exact number of passes. Because they focused their attention on the movement of the ball, over half of them failed to notice something that they didn't expect. Midway through the film, a person dressed in a gorilla suit walked through the circle, stopped, faced the camera, beat its chest, and walked off, spending a full nine seconds in the film. The experiment has been repeated hundreds of times with the same results. (1) Recently, the two psychologists, Christopher Chabris and Daniel Simons, published a book which expands on the gorilla experiment. Entitled The Invisible Gorilla: How Our Intuitions Deceive Us, (2) it demonstrates that all of us are victims of six illusions – attention, memory, confidence, knowledge, cause, and potential.
In the illusion of attention, highlighted in the gorilla experiment, we assume that we see far more of our visual field than we actually do. (3) In this connection, the authors urge people to discontinue the use of both hand-held and hands-free cell phones while driving because studies show that using a cell phone dramatically impairs our ability to perceive unexpected events. (4)
In the illusion of memory, we assume that we remember the past far more accurately than we actually do. (5) For instance, a former basketball player at Indiana University vividly remembered that Coach Bobby Knight had choked him in a rage of anger at a practice but a videotape of the event which surfaced later contradicted the player's story. (6)
In the illusion of confidence, we assume that self-assured people are competent people. (7) Studies show, however, that "the confidence that people project, whether they are diagnosing a patient, making decisions about foreign policy, or testifying in court" is no guarantee that they are as well-informed as they believe. (8)
In the illusion of knowledge, we assume that we know more about a topic than we usually do, whether we're talking about a bicycle, a toilet, a car, or a computer. If we're pressed for explanations, we usually come up short. (9)
In the illusion of cause, we mistake correlation with causality. (10) For instance, because many autistic children are first diagnosed soon after their vaccinations for measles, mumps, and rubella, many parents refuse to have their children vaccinated, despite the fact that dozens of studies with hundreds of thousands of children show that there is no causal link between autism and vaccinations. (11)
Finally, in the illusion of potential, we assume that "simple tricks can unleash the untapped potential" in our minds. (12) For instance, many parents play classical music to their babies to enhance their IQ, despite the fact that there is no scientific evidence to support such a belief. (13)
In a nutshell, then, Christopher Chabris and Daniel Simons challenge all of us to be on the lookout for the invisible gorillas, the everyday illusions that haunt us. To succeed, of course, we must first acknowledge that they exist.
© 2012 Tom Shipka