Economists think about what people ought to do. Psychologists watch what they actually do.

You know, the standard state for people is 'mildly pleasant.' Negative emotions are quite rare, and extremely positive emotions are rare. But people are mildly pleased most of the time, they're mildly tired a lot of the time, and they wish they were somewhere else a substantial part of the time - but mostly they're mildly pleased.

The effort invested in 'getting it right' should be commensurate with the importance of the decision.

Mood evidently affects the operation of System 1: when we are uncomfortable and unhappy, we lose touch with our intuition. These findings add to the growing evidence that good mood, intuition, creativity, gullibility, and increased reliance on System 1 form a cluster. At the other pole, sadness, vigilance, suspicion, an analytic approach, and increased effort also go together. A happy mood loosens the control of System 2 over performance: when in a good mood, people become more intuitive and more creative but also less vigilant and more prone to logical errors.

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.

Researchers who studied a thousand Dutch vacationers concluded that by far the greatest amount of happiness extracted from the vacation is derived from the anticipation period.

People who are cognitively busy are also more likely to make selfish choices, use sexist language, and make superficial judgments in social situations.