translation.en: Twenty years ago, Robert Axelrod used the prisoner's dilemma as a probe of the biological question: if we are here because our ancestors were such fierce competitors, how does cooperation exist at all?
translation.zh: 二十年前，罗伯特阿克塞罗德利用囚犯困境， 进行对生物问题的探索。 如果我们活在此地是因为我们的祖先都是强悍的竞争者， 那么合作又怎么可能存在呢？