Finally, the illusions of validity and skill are supported by a powerful professional culture. We know that people can maintain an unshakeable faith in any proposition, however absurd, when they are sustained by a community of like-minded believers. Given the professional culture of the financial community, it is not surprising that large numbers of individuals in that world believe themselves to be among the chosen few who can do what they believe others cannot.

Question: So investors shouldn't delude themselves about beating the market? Answer: "They're just not going to do it. It's just not going to happen."

People are really happier with friends than they are with their families or their spouse or their child.

Lucky risk takers use hindsight to reinforce their feeling that their gut is very wise. Hindsight also reinforces others' trust in that individual's gut.

Alternative descriptions of the same reality evoke different emotions and different associations.

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

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