Friday, July 16, 2010

Christopher Chabris & Daniel Simons' "The Invisible Gorilla"

This is an excellent popularization of cognitive science. These authors have stunning examples to present the underlying science. The book is full of delightful insights on how we fool ourselves about our "abilities". It is a good antidote to overconfidence.

Here's the argument of the book in a nutshell taken from the conclusion:
... common sense has another name: intuition. What we intuitively accept and believe is derived from what we collectively assume and understand, and intuition influences our decisions automatically and without reflection. Intuition tells us that we pay attention to more than we do, that our memories are more detailed and robust than they are, that confident people are competent people, that we know more than we really do, that coincidences and correlations demonstrate causation, and that our brains have vast reserves of power that are easy to unlock. But in all these cases, our intuitions are wrong, and they can cost us our fortunes, our health, and even our lives if we follow them blindly.
The book attempt to educate the reader into what science does know about our mind and its capabilities. The goal is to rein in the illusions we have about ourselves. These authors are not dogmatic. They are open to other viewpoints and recognize the complexity of the field. I enjoy how they handled Malcolm Gladwell with his intuitive decision making as expressed in the book Blink:
... just as Gladwell's kouros story does not prove that intuition trumps analysis, our Wise story does not prove that analysis always trumps intuition. Intuition has its uses, but we don't think it should be exalted above analysis without good evidence that it is truly superior. The key to successful decision-making, we believe, is knowing when to trust your intuition and when to be wary of it and do the hard work of thinking things through.
Here's their website about the book: At this site you can follow a blog look at other material. I especially enjoy the set of videos they have made available...

Here's the eponymous video:

Here's one that shows that you don't "see" what is right in front of your eyes:

There are six more videos at the the book's site. Watch them!

Yep... I flubbed the "gorilla" test (first video) (and I was duped by all the other tests, wow!). Sure I was incredulous when I was first shown the "invisible gorilla" video. How could I miss something that obvious. But... I did. I love it when something this simple can point up human "frailties" that we all believe ourselves to not have. Well, the book is jam-packed with similar examples. Lots of curious and interesting and utterly flabbergasting displays of human hubris in the face our of puny mental abilities. Read it and be humiliated. But... become wiser. As Socrates said "Know thyself!"

Update 2010oct08: Ernest Davis, professor of computer science at New York University. He is the author of Representations of Commonsense Knowledge (1990) and Representing and Acquiring Geographic Knowledge (1986), has a detailed review of The Invisible Gorilla here. Unfortunately Davis is a hostile reviewer:
Unfortunately, even in these early chapters the quality of the evidence presented is very uneven, and some of the arguments made are weak. The authors discuss at some length the Joshua Bell stunt in which the violinist played his Stradivarius at a subway entrance and was ignored by all but a few of the passersby. The authors analyze this in terms of the illusion of attention, but there is no reason whatever to suppose that Bell was invisible to the commuters in the sense that the gorilla was invisible to the subjects watching the basketball video. All the Bell “experiment” proves is that commuters hurrying home are generally not at leisure to stop and listen to a violin recital. At most, it sheds a sad light on the pressures of life in the 21st century.
I disagree. The Bell "stunt" is a fine example of how a "prepared" mind will see something which an unprepared mind won't. When you go to a Joshua Bell concert, you are prepared to hear a world class violinist. When you are rushing home on a subway you don't expect and therefore don't attend to music from a street musician with the expectation that this is a world class performance. And guess what? You won't notice that it is a world class performance!

I find it funny that Davis acts as a stereotypical academic. He vigorously attacks his "opponent" for minor slipshod steps in reasoning while ignoring his own rather haphazard "reasoning". For example:
Much of the chapter is given over to decrying parents who refuse to have their children vaccinated because of the supposed relation to autism. Chabris and Simons characterize this decision entirely as an instance of the illusion of cause. Certainly, cognitive illusions play a role, but many other factors are involved, including a well-founded public distrust of the pharmaceutical industry.
Wow! He proceeds this with a quibble over a claim by Chabris and Simons that you need experiments to distinguish cause and effect. He is right to point out that this claim is overly broad. But Davis in the very next paragraph (the one above) makes a much broader completely unsubstantiated claim: "a well-founded public distrust of the pharmaceutical industry", is Davis really going to stand behind that claim? Where's the evidence and logic to such a sweeping claim? A wonderful example of a pot calling a kettle black!

I find the review interesting because it is helpful to look at negative as well as positive reviews. You can often learn more from opponents more than supporters. Davis makes some good points, but he is what I call a "typical academic" in his eagerness to overplay his hand using a hyper-critical approach. It is a little off-putting, but not enough to say "don't read the review".

I don't mind Davis being so negative, but I prefer to focus on the positive. Chabris and Simons have written an excellent book for the educated public. They should be congratulated for it, not raked over the coals of hyper-critical nit-picking academic squabbling. The book is valuable for any general reader. It is worth your time. Read it! Look at Davis' criticisms to get a peek at some cautions about taking Chabris and Simons too enthusiastically and too far. But don't let Davis prevent you from reading this book!

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