An ESS is stable, not because it is particularly good for the individuals participating in it, but simply because it is immune to treachery from within. It is possible for humans to enter into pacts or conspiracies that are to every individual’s advantage, even if these are not stable in the ESS sense. But this is only possible because every individual uses his conscious foresight, and is able to see that it is in his own long-term interests to obey the rules of the pact.
