OVERCONFIDENCE

KEEP THE ACTIVITIES ROLLING

OVERCONFIDENCE

The tendency to be more confident than correct—to overestimate the accuracy of our beliefs and judgements

For each of the following questions, answer in terms of a range within which you expect the correct answer will almost certainly fall. Given a 98% confidence level, if you give answers between 100 and 200, for example, this would mean you think there is only a 2 percent chance that the real answer is either less than 100 or more than 200.

1) I feel 98% certain that the area of the US is more than _____ square miles but less than _____ square miles.

2) I feel 98% certain that in 2007 the population of Australia was more than _____ but less than _____.

3) I feel 98% certain that the number of American battle deaths in the Spanish-American War was more than _____ but less than _____.

4) I feel 98% certain that in 2005 the number of female psychiatrists in the United States was more than _____ but less than _____.

5) I feel 98% certain that in 2007 the number of operating nuclear plants in the world was more than _____ but less than _____.

ANSWERS

1. 3.6 million miles2. 20.4 million people3. 385 deaths4. 13,079 female psychiatrists5. 435 nuclear plants