Exploring the limits of optimism: the case of smokers' decision making.

Smokers consider themselves less likely than others to contract smoking-associated diseases. This result has been interpreted as a weak form of irrationality. Alternatively, it can be interpreted as indicating that smokers show an optimism bias. The optimism explanation was examined by having smokers and non-smokers rate the likelihood of future negative events falling into three categories: (1) smoking associated, (2) health related and (3) health unrelated. Subjects rated their likelihood of the event happening to (1) themselves, (2) the average smoker and (3) the average non-smoker. Smokers and non-smokers rated their own likelihood of negative events as less than for the average smoker and the average non-smoker. But, while smokers rated their own risk as higher for both smoking-associated and other health-related problems, they rated their own risk as lower than the average smoker, a standard optimism bias.