August 27, 2008

Roger A. McCain on the implications of the Prisoner's Dilemma

"This remarkable result [derived from the Prisoner's Dilemma thought experiment] -- that individually rational action results in both persons being made worse off in terms of their own self-interested purposes -- is what has made the wide impact in modern social science. For there are many interactions in the modern world that seem very much like that, from arms races through road congestion and pollution to the depletion of fisheries and the overexploitation of some subsurface water resources. These are all quite different interactions in detail, but are interactions in which (we suppose) individually rational action leads to inferior results for each person, and the Prisoners' Dilemma suggests something of what is going on in each of them. That is the source of its power." -- Roger A. McCain
Speaking of which, did you guys catch the game theoretic scenario in The Dark Knight? What do you believe should have been the correct course of action for a decision maker in that situation?


Derek said...

I thought the dilemma as presented in The Dark Knight could have been interesting, but the reactions of the characters involved was silly.

So you have two isolated groups who have the power to kill each other by pressing a button, and a madman who says if neither presses their button by x time, he will kill both groups. You have the added variable of a hero who could possibly save you within the given time frame.

I guess if I knew I was in a Batman movie, and that Batman always saves the day, I might not press the button, expecting Batman to save me. Then again, if I'd known that he had just failed to save the love of his life earlier in the movie, I might not have so much faith in him.

Meanwhile, I have every reason to believe that the Joker is true to his word and will kill both groups by x time.

I also don't know anything about the mindset of the other group. Seems to me the most rational action is to press your button as early as possible.

George said...

Hey Derek, great comment. One of the principles of game theory is minimax (minimizing the maximum possible loss). In this case, given the *very real* potential for both ships to be destroyed (as you noted, priors are important), it would make sense to destroy one boat to save the other, thus preventing the potential for both ships to be lost.

So, as disturbing as it may be, I agree with your assessment!

Anonymous said...

Derek and George both have one fatal assessment involved in their conclusions. They suppose that every single one of the people on those boats was well-educated in the principles of game theory and agreed on the actual action that could/should be taken because of game theory. Just because I know of game theory doesn't mean I agree with the moral implications of its "most reasonable" outcome (which you two are implying).

Anonymous said...

Well, it's an interesting twist, you know. When I first saw that scene I immediately thought, "He'll blow them up after a certain amount of time? WTF? That ruins the whole conundrum", which of course, is the point. The whole idea of the Joker's conundrum is to leave no other options than self-sacrifice for the greater good or chaos, which is one of the main themes in the film (and of the whole Joker character). Would you kill yourself (or accept some other loss) in allegiance to an ethical principle even if the ethical principle explicitly didn't apply in a given situation?

Or, to put it another way, are ethics fundamentally consequentialist? I think that's open to question.

This reminds me of another comic book they're turning into a movie, Watchmen, specifically, to a character named Rorschach. I'm really interested to see if this one turns out to be good, because the whole graphic novel is basically a long string of interesting ethical questions with no answers provided. No wonder they previewed it at The Dark Knight.

Anonymous said...

Looking at the 2x2 graph it's better to push. The option of both pushing available isn't there.
As the dilemma is set up, not pushing leads to a loss, delaying the push might lead to a loss.
The only option to avoid a loss is to push early.
This was one aspect of the movie I found difficult to believe. It's the area I do research in and I know that button would have been pushed.
Not pushing the button is simply not supported by experimental evidence coming out of cognitive science.