Comment on Robust Cooperation in the Prisoner's Dilemma

Thu, 13 Jun 2013 16:15:49 GMT

It depends on how they use their intelligence. For instance, consider the variant of FairBot that appears in the last Masquerade post, which oscillates between seeking proofs of its opponent's cooperation and defection, up to a high threshold.

The original FairBot, or PrudentBot, or Masquerade, all reach mutual cooperation with this variant (call it ToughButFairBot), despite its undecidability in general up to PA+N. That's because if it finds a proof at a lower level, it acts on that immediately, so you can figure out what it does in those particular cases without climbing too high up the tower of formal systems.

The upshot is that you can have higher levels of strategy when necessary, without sacrificing your ability to provably act on lower levels in other cases. So this principle doesn't cash out as "defect against anyone smarter than you", but rather as "defect against anyone who refuses to let you figure out how they're going to respond to you in particular".

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