The prisoner's dilemma is a classic illustration of why rational people don't always cooperate--even when it's in their best interest to do so. In this episode of Instant Egghead, Scientific American editor Michael Moyer explains how it works.

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5 Comments

1. 1. MAJ55 02:20 PM 5/31/12

   Of course, individuals will usually focus on what they perceive to be in their narrow self-interest. Nations, and leaders of nations, however should have evolved a more sophisticated rationality. I said, "should have."

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2. 2. eurotimbr 07:38 PM 5/31/12

   I think the essential hard part of this problem is that neither party can reliably predict what the other will do, so neither party knows which choice is truly in their own interest. Given that, I don't see how defecting is the rational choice. I don't think there is a "rational" choice.

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3. 3. timbo555 in reply to MAJ55 06:14 PM 6/2/12

   Nations, and leaders of nations, however should have evolved a more sophisticated rationality. I said, "should have."
   
   MAJ55: Spoken like a true collectivist. Nations are made up of people, all people everywhere belong to either democratic republics, or despotic dictatorships, or something in between. All nation states are made up of individuals, however oppressed or free they find themselves on that spectrum. No nation can evolve higher ideals than the people they govern. The people are born inherently free. Nations only serve to reign in that freedom, which makes them necessarily less evolved than the least of their citizens.
   
   Whenever I hear someone say WE should do away with carbon, or WE should give more money to the poor, I wonder who he or she is talking about. I get the distinct feeling that some people would like to do what's best for all of us. That is not evolving to a higher state, that is DEvolving us to a state of collectivism. God help us.....

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4. 4. mss712 in reply to timbo555 10:27 PM 6/2/12

   So am I to understand that your contention is that compromise, cooperation, or dissemination of symmetric information to all parties working towards anything considered a "common good" is a regression to an inferior state while removal of all restraints on individuals is an evolution to a higher plane? Don't misunderstand me. I believe all governments are corrupt to one extent or another. However, mankind as a whole and individually are just as flawed. Only with man achieving a higher plane before removing restraints would it be possible to survive as a species. As it stands now, we are no more than a highly intelligent animal that is reproducing ourselves to extinction.

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5. 5. tgrigsby 01:31 PM 11/6/12

   The prisoner's dilemma is interesting, but the usual treatment ignores the additional pressure that always arises. In every society with a large enough criminal element, a stigma arises against those that "rat out" other criminals, and those that do so face a severe punishment not described in the prisoner's dilemma. This possible outcome creates a predictability in behavior and weights the outcome in favor of the situation where the criminals stay silent and take the least of the possible punishments.

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