Game Theory - Prisoner's dilemma

Because defection always results in a better payoff than cooperation regardless of the other player's choice, it is a dominant strategy.

The dilemma, then, is that mutual cooperation yields a better outcome than mutual defection but is not the rational outcome because the choice to cooperate, from a self-interested perspective, is irrational.

They don´t cooperate, so the only rational thing to do is to talk! They are talking ALL OF THEM!!! It is the only choice they have!