You Are Not So Smart

Here is a logic puzzle created by psychologists Daniel Kahneman and Amos Tversky.

Linda is single, outspoken, and very bright. She majored in philosophy. As a student, she was deeply concerned with the issue of discrimination and social justice, and also participated in demonstrations. Which of the following is more probable: Linda is a bank teller or Linda is a bank teller AND is active in the feminist movement?

In studies, when asked this question, more than 80 percent of people chose number two. Most people said it was more probably that Linda is a bank teller AND active in the feminist movement, but that's wrong. Can you tell why?

This thinking mistake is an example of the subject of this episode - the conjunction fallacy. Listen as three experts in logic and reasoning explain why people get this question wrong, why it is wrong, and how you can avoid committing the conjunction fallacy in other situations.

Direct download: 077_-_The_Conjunction_Fallacy.mp3
Category:psychology -- posted at: 11:03am EDT