Human brains didn't evolve to deal with these kinds of problems, so when we encounter them, we take mental shortcuts, like "There are three doors. There is one

Human brains didn't evolve to deal with these kinds of problems, so when we encounter them, we take mental shortcuts, like "There are three doors. There is one good prize. The odds are one in three". It's actually a really big cognitive leap to get from there to the idea that, because the gameshow host knows the answer, that the visible answer differs from the mental shortcut. I've got a good friend who speaks at a lot of risk management seminars, and a good deal of people who deal with financial risk every day get this question wrong. He's got a really good blog at http://behavioralrisk.net/ http://behavioralrisk.net/