We submitted the classic “Linda problem” from Tversky and Kahneman (1983) to fifty workers (23 women, 46% women, mean age = 32.9). Participants were paid $0.05 for a HIT that comprised other unrelated brief tasks. Participants were given the following information and the following question:
Linda is 31 years old, single, outspoken, and very bright. She majored in philosophy. As a student, she was deeply concerned with issues of discrimination and social justice, and also participated in anti-nuclear demonstrations.
Which of these two alternatives is more probable?
- Linda is a bank teller.
- Linda is a bank teller and is active in the feminist movement.
43 participants (86%) indicated the second alternative as more probable, thus exhibiting the classic conjunction fallacy. Such result is consistent with previous research.
Tversky, A., Kahneman, D. (1983). Extensional versus intuitive reasoning: The conjunction fallacy in probability judgment. Psychological Review, 90, 293–315.