Epstein (1998) demonstrates that in the demographic Prisoner's Dilemma game it is possible to sustain cooperation in a repeated game played on a finite grid, where agents are spatially distributed and of fixed strategy type ('cooperate' or 'defect'). We introduce a methodology to formalize the...

We offer a game-theoretic proof of Hamilton's rule for the spread of altruism. For a simple case of siblings, we show that the rule can be derived as the outcome of a one-shot prisoner's dilemma game between siblings. -- evolution of altruism ; Hamilton's rule ; one-shot prisoner's dilemma game