Most impressions and thoughts arise in your conscious experience without your knowing how they got there. But that is not the only way the mind works, or indeed is that the typical way. You believe you know what goes on in your mind, which often consists of one conscious thought leading in an orderly way to another. When you are asked what you are thinking about, you can normally answer. The availability of a diagnostic label for this bias- the halo effect-makes it easier to anticipate, recognize, and understand. When the handsome and confident speaker bounds to the stage, for example, you can anticipate that the audience will judge his comments more favorably than he deserves. Systematic errors are known as biases: they recur predictably in particular circumstances. The hope for informed gossip is that there are distinctive patterns in the errors people make. A deeper understanding of judgments and choices also requires a richer vocabulary than is available in everyday language. Learning medicine consists in part of learning the language of medicine. To be a good diagnostician, a physician needs to acquire a large set of labels for diseases, each of which binds an idea of the illness and its symptoms, possible antecedents and causes, possible developments and consequences, and possible interventions to cure or mitigate the illness. The expectation of intelligent gossip is a powerful motive for serious self-criticism, more powerful than New Year resolutions to improve one's decision making at work and at home. Many of us spontaneously anticipate how friends and colleagues will evaluate our choices the quality and content of these anticipated judgments therefore matters. Questioning what we believe and want is difficult at the best of times, and especially difficult when we most need to do it, but we can benefit from the informed opinions of others. Why be concerned with gossip? Because it is much easier, as well as far more enjoyable, to identify and label the mistakes of others than to recognize our own.

I hope to enrich the vocabulary that people use when they talk about the judgments and choices of others, the company's new policies, or a colleague's investment decisions. Mine is the proverbial office water-cooler, where opinions are shared and gossip is exchanged.

Every author, I suppose, has in mind a setting in which readers of his or her work could benefit from having read it.

Thinking fast and slow book review