Book review of

Book review of

In 2002, Daniel Kahneman won the Nobel in economic science. What made this unusual is that Kahneman is a book review of. Human irrationality is Kahneman’s great theme. There are essentially three phases to his career.

It is an astonishingly rich book: lucid, profound, full of intellectual surprises and self-help value. It is consistently entertaining and frequently touching, especially when Kahneman is recounting his collaboration with Tversky. Now, this worries me a bit. A leitmotif of this book is overconfidence. All of us, and especially experts, are prone to an exaggerated sense of how well we understand the world — so Kahneman reminds us. Surely, he himself is alert to the perils of overconfidence. Such sweeping conclusions, even if they are not endorsed by the author, make me frown.

System 2, in Kahneman’s scheme, is our slow, deliberate, analytical and consciously effortful mode of reasoning about the world. System 1, by contrast, is our fast, automatic, intuitive and largely unconscious mode. More generally, System 1 uses association and metaphor to produce a quick and dirty draft of reality, which System 2 draws on to arrive at explicit beliefs and reasoned choices. System 1 proposes, System 2 disposes.

So System 2 would seem to be the boss, right? But System 2, in addition to being more deliberate and rational, is also lazy. At this point, the skeptical reader might wonder how seriously to take all this talk of System 1 and System 2. Are they actually a pair of little agents in our head, each with its distinctive personality? Participants in the experiment were told about an imaginary young woman named Linda, who is single, outspoken and very bright, and who, as a student, was deeply concerned with issues of discrimination and social justice. And this, according to Kahneman, is the source of many of the biases that infect our thinking.

The cumulative effect is to make the reader despair for human reason. Think again of the Linda problem. Even the great evolutionary biologist Stephen Jay Gould was troubled by it. This might seem a minor point. But it applies to several of the biases that Kahneman and Tversky, along with other investigators, purport to have discovered in formal experiments.

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View all New York Times newsletters. Some cognitive biases, of course, are flagrantly exhibited even in the most natural of settings. Now, in one sense, a bias toward optimism is obviously bad, since it generates false beliefs — like the belief that we are in control, and not the playthings of luck. Even if we could rid ourselves of the biases and illusions identified in this book — and Kahneman, citing his own lack of progress in overcoming them, doubts that we can — it is by no means clear that this would make our lives go better. And that raises a fundamental question: What is the point of rationality?

We are, after all, Darwinian survivors. Kahneman never grapples philosophically with the nature of rationality. He does, however, supply a fascinating account of what might be taken to be its goal: happiness. What does it mean to be happy? When Kahneman first took up this question, in the mid 1990s, most happiness research relied on asking people how satisfied they were with their life on the whole.

Two groups of patients were to undergo painful colonoscopies. The patients in Group A got the normal procedure. As with colonoscopies, so too with life. It is the remembering self that calls the shots, not the experiencing self. Kahneman’s conclusion, radical as it sounds, may not go far enough. There may be no experiencing self at all. Clearly, much remains to be done in hedonic psychology.