Optimistic people play a disproportionate role in shaping our lives. Their decisions make a difference; they are inventors, entrepreneurs, political and military leaders - not average people. They got to where they are by seeking challenges and taking risks.

We are often confident even when we are wrong, and an objective observer is more likely to detect our errors than we are.

Nobody would say, 'I'm voting for this guy because he's got the stronger chin,' but that, in fact, is partly what happens.

Except for some effects that I attribute mostly to age, my intuitive thinking is just as prone to overconfidence, extreme predictions, and the planning fallacy as it was before I made a study of these issues.

Political columnists and sports pundits are rewarded for being overconfident.

So your emotional state really has a lot to do with what you're thinking about and what you're paying attention to.

To know whether you can trust a particular intuitive judgment, there are two questions you should ask: Is the environment in which the judgment is made sufficiently regular to enable predictions from the available evidence? The answer is yes for diagnosticians, no for stock pickers. Do the professionals have an adequate opportunity to learn the cues and the regularities? The answer here depends on the professionals' experience and on the quality and speed with which they discover their mistakes.