title: Emergence of cooperation among interacting individuals.
abstract: We study the evolution of interacting individuals located on the sites of a regular lattice. The individuals play a two action game in which the players either cooperate or defect with respect to a certain issue. The main rule of the game is that a player does not change his action when he and his opponent have held the same action in the previous round. Numerical simulations performed on a square lattice show a stationary state in which the lattice has a finite number of cooperators and defectors and two frozen states, one full of cooperators and the other full of defectors.
authors.affiliation: Faculdade de Filosofia Letras e Ciências Humanas, Universidade de São Paulo, São Paulo, SP, Brazil.
authors.forename: J R
authors.initials: JR
authors.lastname: Chiappin
authors.forename: M J
authors.initials: MJ
authors.lastname: de Oliveira