It seems the Postmodernists might have the best untapped fertile ground for evaluating the Prisoner Dilemma. One such approach would be to think about it like this:
1. The dominant social In-Group, represented by the Police, subscribes to a Moral Theory that is defined by the comparative moral value of Selfishness vs Cooperation
2. Our Prisoners are evidently in jail because their actions indicate they subscribe to an Out-Group Moral Theory (defined by a certain comparison of Selfishness vs Cooperation) that deviates from the In-Group's
3. The Police (or more broadly, the "In-Group Justice System") consider it their job to eliminate deviant Moral Theories through rewards and punishments ("re-education")
4. It is very plausible that, over the years, the Police have experimented with different Dilemmas and have observed the extent to which the responses of the various prisoners indicate improved conformity to the In-Group Moral Theory
5. Therefore, our Prisoner's can probably assume that the particular Dilemma they face is the product of an ongoing evolutionary trial-and-error process that that seeks to maximize conformity to In-Group Morality based upon empirical expectations of prisoner responses
6. In certain well-defined game theoretic models of this, we might make additional simplifying assumptions (that In-Group Morality and Out-Group Morality are well-defined, that the In-Group rigidly maintains its Morality, that the Out-Group adapts its Morality in response to In-Group actions based on In-Group values, that adaptive responses can be modeled, etc)
In other words, this interpretation seems to suggest that the question, "Why am I being presented with this particular Dilemma in this particular form?" might be a more decidable or relevant question than, "How do I make the decision with the expected outcome most consistent with My values?"
These Dilemmas are normally structured such that:
1. Self-interest is our Prisoners' assumed priority
2. There does not exist a strategy to maximize Self-interest.
So in that sense, the second question, strategical optimization, is undecidable and therefore irrelevant.
However, the Prisoners can make some educated guesses about why they have been put into the Dilemma. Specifically, it is plausible that:
1. The Police have a wealth of experience in dealing with prisoners (aka, "the Out-Group", aka "People Like Them", aka "Those Kinds of People", etc)
2. The Police have deliberately engineered a Dilemma that is utterly resistant to optimization strategies corresponding to Out-Group values
3. This was done to induce behavior that is outside of textbook Out-Group Morality
4. The statistically expected behavior is more reflective of In-Group Morality than Out-Group Morality
These considerations regarding the first question ("Why this Dilemma?") may well be more worthwhile to our Prisoners than trying to solve the unsolvable second question
The de facto unsolvability of the second question, along with consideration of the first question, suggests the possibility of an alternative strategy with an alternative goal. That is to say, our Prisoners might reason like this:
"Those sneaky In-Group bastards! They have concocted this bogus Dilemma to frustrate my ability to act according to my principles. But Achilles might have a vulnerable heel. It is possible that I can evaluate the rewards, punishments, and hypothetical expected responses in order to behave in a way contrary to In-Group values. Even though such behavior is inconsistent with my values, I am still stickin' it to the man by defying his values"
In other words, even if a "strategy of optimization" is impossible, a "strategy of resistance" may still be viable
It seems the Postmodernists might have the best untapped fertile ground for evaluating the Prisoner Dilemma. One such approach would be to think about it like this:
1. The dominant social In-Group, represented by the Police, subscribes to a Moral Theory that is defined by the comparative moral value of Selfishness vs Cooperation
2. Our Prisoners are evidently in jail because their actions indicate they subscribe to an Out-Group Moral Theory (defined by a certain comparison of Selfishness vs Cooperation) that deviates from the In-Group's
3. The Police (or more broadly, the "In-Group Justice System") consider it their job to eliminate deviant Moral Theories through rewards and punishments ("re-education")
4. It is very plausible that, over the years, the Police have experimented with different Dilemmas and have observed the extent to which the responses of the various prisoners indicate improved conformity to the In-Group Moral Theory
5. Therefore, our Prisoner's can probably assume that the particular Dilemma they face is the product of an ongoing evolutionary trial-and-error process that that seeks to maximize conformity to In-Group Morality based upon empirical expectations of prisoner responses
6. In certain well-defined game theoretic models of this, we might make additional simplifying assumptions (that In-Group Morality and Out-Group Morality are well-defined, that the In-Group rigidly maintains its Morality, that the Out-Group adapts its Morality in response to In-Group actions based on In-Group values, that adaptive responses can be modeled, etc)
In other words, this interpretation seems to suggest that the question, "Why am I being presented with this particular Dilemma in this particular form?" might be a more decidable or relevant question than, "How do I make the decision with the expected outcome most consistent with My values?"
These Dilemmas are normally structured such that:
1. Self-interest is our Prisoners' assumed priority
2. There does not exist a strategy to maximize Self-interest.
So in that sense, the second question, strategical optimization, is undecidable and therefore irrelevant.
However, the Prisoners can make some educated guesses about why they have been put into the Dilemma. Specifically, it is plausible that:
1. The Police have a wealth of experience in dealing with prisoners (aka, "the Out-Group", aka "People Like Them", aka "Those Kinds of People", etc)
2. The Police have deliberately engineered a Dilemma that is utterly resistant to optimization strategies corresponding to Out-Group values
3. This was done to induce behavior that is outside of textbook Out-Group Morality
4. The statistically expected behavior is more reflective of In-Group Morality than Out-Group Morality
These considerations regarding the first question ("Why this Dilemma?") may well be more worthwhile to our Prisoners than trying to solve the unsolvable second question
The de facto unsolvability of the second question, along with consideration of the first question, suggests the possibility of an alternative strategy with an alternative goal. That is to say, our Prisoners might reason like this:
"Those sneaky In-Group bastards! They have concocted this bogus Dilemma to frustrate my ability to act according to my principles. But Achilles might have a vulnerable heel. It is possible that I can evaluate the rewards, punishments, and hypothetical expected responses in order to behave in a way contrary to In-Group values. Even though such behavior is inconsistent with my values, I am still stickin' it to the man by defying his values"
In other words, even if a "strategy of optimization" is impossible, a "strategy of resistance" may still be viable