Rushing to Judgment
THINKING, FAST AND SLOW.
By Daniel Kahneman.
Farrar, Straus & Giroux. 499 pp. $30
Body and soul, reason and passion, yin and yang—expressions of twoness pervade the world’s cultures, perhaps because duality comes naturally to creatures divided into males and females and destined to live through daily cycles of light and dark.
Dualism is the organizing principle of Daniel Kahneman’s Thinking, Fast and Slow, a genial survey of human irrationality that serves as an admirable summa of the author’s extraordinary life’s work. His pioneering research mapping the vast territory of human irrationality, much of it done with the late Stanford psychologist Amos Tversky, helped Kahneman win the 2002 Nobel Prize in Economics—even though he’s a psychologist.
Since then, irrationality has become a growth industry, both for scholars such as Duke psychologist Dan Ariely and popular science writers including Jonah Lehrer, but few authors have thought as long or as deeply about the subject as Kahneman. The central message of this accessible book is that most of us simply have no idea how illogical, impressionable, and downright inept we are when it comes to making judgments.
Imagine, for instance, a man described as meek, shy, tidy, and helpful. Is he more likely to be a librarian or a farmer? Most of us will answer librarian, thereby falling for what Kahneman calls the representativeness heuristic. It may be true that librarians tend to fit the description, but there are 20 times as many male farmers as male librarians in this country. So it’s much likelier that the man described grows food for eating rather than catalogues food for thought.
Our divided nature is partly to blame for our bad judgment. Broadly speaking, humans have a hasty and appetitive instinctual side, and a more patient, forward-looking reasoning side that supposedly provides some sort of supervision. Kahneman describes them as System 1 and System 2, respectively. The former provides most of the processing that gets us through our days. System 1’s snap judgments are often correct, but on more complex matters it can too easily victimize us. It can be “primed” through the power of suggestion, for example. And it’s susceptible to mere repetition, which it credulously mistakes for veracity. System 2 is our conscious, more rational self, and ought to ask, for instance, whether we are sure there are very many male librarians. But it’s lazy and easily tired, often bestirring itself just enough to certify that System 1 was right after all.
A second dualism in Kahneman’s book is the one between what behavioral economist Richard Thaler dubbed the Econs, the imaginary species whose members, found only in textbooks, act in rigid conformity to the models of economists, and the Humans, who instead act like real people, illogical though they may be. This distinction pervades the book, just as it pervades the author’s work. (It’s the reason a psychologist was awarded a Nobel in economics.) Finally, there is the division between the experiencing self and the remembering self, a dualism that is the basis for a fascinating meditation on how we make judgments about whether we are happy, which of these “selves” we choose to serve when we plan a vacation, and why we discount years of happy marriage or productive work if they end in a divorce or layoff (because endings loom disproportionately large in human memory).
Kahneman’s work should be of profound interest to policymakers, whose job, after all, is making difficult choices for society. He cautions against the human tendency to vastly overweight unlikely events, for example, as well as the tendency to answer an easy question (do I like this person?) when we can’t answer the hard one at hand (how good a surgeon is this?). Overconfidence and delusional optimism are rampant, so we should rely whenever possible on simple formulas and checklists that measure things strongly associated with a desired outcome. Dumb luck explains a lot more of life than most of us realize, so we must beware of our tendency to create narratives that conjure causality. Kahneman even dispenses advice on how to improve your meetings: “Before an issue is discussed, all members of the committee should be asked to write a very brief summary of their position”; otherwise, whoever talks first and most will likely sway the others.
Kahneman observes that we are often disastrously content with the inadequate information before us, but he doesn’t address how we are to know when we have enough data to make a good enough choice. Humans must constantly assess whether the cost of searching—for new information or additional options—has become too high. Working at a newspaper, according to an old saying, involves making judgments about the world with too little time and too little information. The problem, unfortunately, is even worse in life.