A new version of the Monty Hall Dilemma with unequal probabilities.

In the Monty Hall Dilemma (MHD), a contestant makes a guess as to which door conceals a prize. The host then reveals the contents of an unchosen, incorrect door, and then gives the contestant a choice of sticking with the initial guess or switching to the remaining door. Given certain crucial assumptions, the rational solution is to switch. In the present study, subjects played 60 trials of either a standard four-door MHD or a new version of the MHD with unequal probabilities. Each has a counterintuitive solution. Subjects showed a strong tendency to stick when they should switch. Some learning took place, but switching in the standard condition reached a plateau. The results indicate that the equal probability condition is more suitable for studying satisficing, while the unequal probability condition is better for studying insightful learning.