Daniel Kahneman introduces his sweeping and insightful book with an odd little objective; he hopes that those who read Thinking, Fast and Slow will become better at gossip. As he explains, most people are better at judging their friends than at judging themselves, a situation unlikely to change any time soon. But since most people are also pretty well aware of their friends’ judgments, more intelligent gossip might be just as good as honest self-evaluation. The only catch is that for this book to actually raise the quality of your local gossip, it’s not enough for you to read the book alone; all your friends will have to read it, too. But we don’t think too many of your friends will mind.
Thinking, Fast and Slow is the best sort of popular psychology book. There’s no over-simplification, no promises to fix your love-life and clean your dishes in just six easy steps. Instead, this is actual psychology, a real scholarly explanation complete with appendices and bibliographical notes and an index—and it’s readable. Everywhere the tone is clear and personable, and sometimes it’s even sweet or funny. And it provides the surprisingly delightful shock of proving that you know less about your own mind than you thought you did.
The central insight of the book is that in addition to the (semi) rational part of our minds that we identify with, there is another part that actually does most of our mental work. This is the fast thinking of the title, or System I, as Kahneman calls it elsewhere, and it uses a system of automatic short-cuts to give us ball-park answers to the questions of daily life. System II, the slower, deliberate part, keeps an eye on things to catch mistakes. System II also takes over whenever System I needs help. Kahneman is at pains to make clear that these two systems are actually just metaphors, not brain structures or separate personalities. The point is that most of the time our thoughts are not what we think they are.
Kahneman lays these hidden thought processes bare, and shows them to be more alike, and more wrong, than is entirely comfortable to admit. He can and does describe the reader’s responses to the exercises in the book with uncanny accuracy, because the exercises are designed to catch System I making mistakes that essentially everyone makes. Most of the exercises involve math or statistics, and most seem fairly inconsequential, but studies have shown that even highly educated people make analogous mistakes, even when the stakes are very high. One of the most chilling involved parole judges granting fewer paroles right before lunch, without realizing they had become biased. Kahneman’s ultimate goal, and the real treasure of the book, is to teach readers when and how System I is likely to run into trouble, and how to bring System II to its aid. This book is nothing less than an owner’s manual for the human mind.
It’s curious that Thinking, Fast and Slow covers much the same ground as several other books published in recent years, including The Science of Fear and Don’t Believe Everything You Think. All address the basic discrepancy between how we think we think and how we actually think, and all present themselves as useful ways to avoid making otherwise predictable and possibly serious mistakes. While each book has its own distinct take on the subject, they do tend to use a lot of the same arguments and examples. The curious resemblance of the other books to this one is not likely a coincidence. Daniel Kahneman has had a long and very influential career (he won a Nobel Prize for some of the work he summarizes in this book), and he has had the privilege of working with a number of other very influential people in psychology and related fields. The other books are well worth reading, but this is the man whose work likely got the others started.