Wednesday, December 1, 2010
The Invisible Gorilla by Chabris and Simons
The authors made a short film of two teams of people moving around and passing basketballs. One team wore white shirts and the other wore black. They asked volunteers to silently count the number of passes made by the players wearing white while ignoring any passes made by the players wearing black. The video lasted less than a minute. After it was over the subjects of the experiment were asked to report how many passes they'd counted. It didn't really matter. The pass-counting was intended to keep people engaged in doing something that demanded attention, they weren't really interested in their pass-counting ability. The authors were actually testing something else.
Halfway through the video, a female student wearing a full-body gorilla suit walked into the scene, stopped in the middle of the players, faced the camera, thumped her chest, and then walked off, spending about nine seconds on screen. After asking subjects about the passes, they asked the important question: “Did you notice anything unusual while you were doing the counting task?”...”Did you notice the Gorilla?”
Amazingly, roughly half of the subjects in the study did not notice the gorilla. The authors repeated the experiment many times, under different conditions, with diverse audiences, and in multiple countries but the results were always the same. The failure of half the subjects to see the gorilla goes by the scientific name of “inattentional blindness”. People look at something but don't see it because it is unexpected and their attention is focused on something else.
What prompted the authors to write this book, however, was not inattentional blindness, a known and easily recognized phenomena, but the surprise people showed when they realized what they had missed: they were shocked! When shown the video again some even suspected that the authors had included the gorilla in the second production but not the first. On the other side of the coin, those subjects who saw the gorilla on the first viewing could hardly believe others had missed it!
The author's elaboration on this theme, the unjustified confidence people have in their own cognitive abilities and its implications, throughout the rest of the book. It is the cause of many accidents; on land, on the sea and in the air. Humans have a hard time dealing with the unexpected, especially when they are concentrating on specific, detailed and routine tasks. Neither is there any evidence that people should be confident of their ability to perform many tasks at the same time with any competence. They also consistently over-rate their ability to make sound and successful judgments when dealing with large and complex masses of data. They often infer causation when circumstances only demonstrate coincidence and correlation, and they tend to be excessively confident in those inferences. The less competent people are in performing a given task- playing chess for instance- the greater their confidence that they perform competently tends to be. Regardless of demonstrative cognitive ability the more confidence people show in their judgments the more likely it is that other people will believe and follow them.
One of the most striking implications of the effect of this over-confidence in our cognitive abilities presented by the authors concerns our criminal justice system, especially the undue weight given to eye-witness testimony by prosecutors and juries. In fact, mistaken eyewitness identifications, and their confident presentation to the jury, are the main cause of over 75% of wrongful convictions that are later overturned by DNA evidence. Among other inconvenient discoveries , experiments have revealed that the more detailed the description a witness gives of a suspect to police in writing, the less likely it is that she/he will correctly identify the real perpetrator in a visual line-up.
The authors cover a wide range of damages caused by the various mis-perceptions and fallacies associated with over-confidence and love of confidence in our and other people's cognitive abilities- from Wall Street to Main Street. They go into how this tendency is used by advertisers, public relations and pseudo -scientific experts to wring every possible dollar out of the consuming public with such techniques as technobabble, nuerobabble and brain porn.
In conclusion the authors admit that their message is negative:
“Be wary of your intuitions, especially intuitions about how your own mind works. Our mental systems for rapid cognition excel at solving problems they evolved to solve, but our cultures, societies and technologies today are much more complex than those of our ancestors. In many cases intuition is poorly adapted to solving problems in the modern world. Think twice before you decide to trust intuition over rational analysis, especially in important matters, and watch out for people who tell you intuition can be a panacea for decision-making ills.”
But we also have an affirmative message. You can make better decisions, and maybe even live a better life, if you do your best to look for the invisible gorilla in the world around you. There may be important things right in front of you that you aren't noticing due to the illusion of attention, do not automatically assume you're seeing everything there is to see. You may think you remember some things much better than you really do, because of the illusion of memory, so try to corroborate your memory in important situations. Recognize that the confidence people express often reflects their personality rather than their knowledge, memory or ability. Be wary of thinking you know more about a topic than you really do, and test your own understanding before mistaking mere familiarity for knowledge. You won't think you know the cause of something when all you really know is what happened before it or what tended to accompany it. You'll be skeptical of claims that simple tricks can unleash the untapped potential in your mind, but you'll be aware that you can develop phenomenal levels of expertise if you study and practice the right way.
When you think about the world with an awareness of everyday illusions, you won't be as sure of yourself as you used to be, but you will have new insights into how your mind works and new ways of understanding why people act the way they do. Often, it's not because of stupidity, arrogance, or lack of focus. It's because of the everyday illusions that affect us all. Our final hope is that you will always consider this possibility before you jump to a harsher conclusion."