What does GDT recommend in the (Identical) Twin Prisoner’s Dilemma? Well, since they share the same genetic material, they are the same agent, meaning if one of them decides to cooperate the other one will also cooperate (and the same for defection). It is therefore best to cooperate since \(u(C, C) > u(D, D)\).
We could then say that GDT “outperforms” CDT in the (Identical) Twin Prisoner’s Dilemma (just as FDT “outperforms” CDT). But this is clearly not meaningful nor interesting: (i) we never argued for why this conception of an agent is useful or intuitive (and it is the choice of ontology that is ensuring cooperation here, nothing else); and (ii) and the decision problem in question—the Twin Prisoner’s Dilemma—is now a different decision problem in the genetic ontology (and we are, in fact, operating in this ontology since we are applying GDT). You are that other person in the other room, it is not just your twin with whom you are correlated.
GDT would perform poorly in Gene Prisoner’s Dilemma: Both players have same genes but different decision theories. GDT would cooperate and get defected against.
There isn’t a corresponding failure mode for TDT though right? Is there?
GDT would perform poorly in Gene Prisoner’s Dilemma: Both players have same genes but different decision theories. GDT would cooperate and get defected against.
There isn’t a corresponding failure mode for TDT though right? Is there?