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.

The extra daily social time of 1.7 hours in weekends raises average happiness by about 2%.

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

One study found that people who just thought about watching their favorite movie actually raised their endorphin levels by 27 percent.

There is a huge wave of interest in happiness among researchers. There is a lot of happiness coaching. Everybody would like to make people happier.

Many people will admit that they made a mistake [putting money in dot-coms or telecoms at their peak] But that doesn’t mean that they’ve changed their mind about anything in particular. It doesn’t mean that they are now able to avoid that mistake.

Intuitive diagnosis is reliable when people have a lot of relevant feedback. But people are very often willing to make intuitive diagnoses even when they're very likely to be wrong.