Cooperation and Defection
The fundamental tension in game theory between working together for mutual benefit (cooperation) and pursuing self-interest at others’ expense (defection). This tension underlies the prisoners-dilemma, the tragedy of the commons, and many real-world social, economic, and security dilemmas.
In Evolutionary Game Theory
robert-axelrod modeled cooperation and defection as a continuous strategy space defined by:
- Boldness: The probability of defecting when one believes one is observed
- Vengefulness: The probability of punishing an observed defector
These dimensions allow the model to trace how populations shift between cooperative and defective equilibria over evolutionary time. 1
Cross-Domain Connections
- security: The attacker-defender dynamic is a cooperation/defection game — attackers defect from the “cooperate on security” equilibrium.
- blockchain: Consensus mechanisms are designed to make defection (e.g., double-spending, 51% attacks) unprofitable.
- organizational-behavior: Free-rider problems in teams, collective action failures.
- sympathy: Smith’s fellow-feeling is the psychological substrate that makes cooperation feel binding rather than merely strategic; de Grouchy’s crib-to-humanity arc is its developmental account.
- mutual-aid: Kropotkin’s cooperation-as-evolutionary-factor is the biological framing of this page’s game-theoretic one: tribal solidarity and guild mutualism as cooperation equilibria maintained without central enforcement.
Sources
See Also
- norms
- metanorms
- evolutionary-game-theory
- robert-axelrod
- ten-crack-commandments — defection-prone game played under lethal enforcement, written down as street doctrine