Everything Is Obvious_ _Once You Know the Answer - Duncan J. Watts [26]
Like rational choice theory, in other words, common sense insists that people have reasons for what they do—and this may be true. But it doesn’t necessarily allow us to predict in advance either what they will do or what their reasons will be for doing it.28 Once they do it, of course, the reasons will appear obvious, and we will conclude that had we only known about some particular factor that turned out to be important, we could have predicted the outcome. After the fact, it will always seem as if the right incentive system could have produced the desired result. But this appearance of after-the-fact predictability is deeply deceptive, for two reasons. First, the frame problem tells us that we can never know everything that could be relevant to a situation. And second, a huge psychological literature tells us that much of what could be relevant lies beyond the reach of our conscious minds. This is not to say that humans are completely unpredictable, either. As I’ll argue later (in Chapter 8), human behavior displays all sorts of regularities that can be predicted, often to useful ends. Nor is it to say that we shouldn’t try to identify the incentives that individuals respond to when making decisions. If nothing else, our inclination to rationalize the behavior of others probably helps us to get along with one another—a worthy goal in itself—and it may also help us to learn from our mistakes. What it does say, however, is that our impressive ability to make sense of behavior that we have observed does not imply a corresponding ability to predict it, or even that the predictions we can make reliably are best arrived at on the basis of intuition and experience alone. It is this difference between making sense of behavior and predicting it that is responsible for many of the failures of commonsense reasoning. And if this difference poses difficulties for dealing with individual behavior, the problem gets only more pronounced when dealing with the behavior of groups.
CHAPTER 3
The Wisdom (and Madness) of Crowds
In 1519, shortly before he died, the Italian artist, scientist, and inventor Leonardo da Vinci put the finishing touches on a portrait of a young Florentine woman, Lisa Gherardini del Giocondo, whose husband, a wealthy silk merchant, had commissioned the painting sixteen years earlier to celebrate the birth of their son. By the time he finished it, Leonardo had moved to France at the invitation of King François I, who eventually purchased the painting; thus apparently neither Ms. del Giocondo nor her husband ever got the chance to view Leonardo’s handiwork. Which is a pity really, because five hundred years later that painting has made her face about the most famous face in all of history.
The painting, of course, is the Mona Lisa, and for those who have lived their entire lives in a cave, it now hangs in a bulletproof, climate-controlled case on a wall all by itself in the Musée du Louvre in Paris. Louvre officials estimate that nearly 80 percent of their six million visitors each year come primarily to see it. Its current insurance value is estimated at nearly $700 million—far in excess of any painting ever sold—but it is unclear that any price could be meaningfully assigned to it. The Mona Lisa, it seems fair to say, is more than just a painting—it is a touchstone of Western culture. It has been copied, parodied, praised, mocked, co-opted, analyzed, and speculated upon more than any other work of art. Its origins, for centuries shrouded in mystery, have captivated scholars, and its name has leant itself to operas, movies, songs, people, ships—even a crater on Venus.1
Knowing all this, a naïve visitor to the Louvre might be forgiven for experiencing a sense of, well, disappointment upon first laying eyes on the most famous painting in the world. To start with, it is surprisingly small. And being enclosed in that bulletproof box, and invariably surrounded by mobs