Game Theory’s Tit-for-Tat is Just a Mathematically Complete Version of Religion’s Golden Rule

The Golden Rule mandating that you treat others as you want them to treat you is simply a variation on tit-for-tat, one that emphasizes the benefit rather than the harm side. (The Christian principle of returning a favor for a harm in this respect is highly unusual and, one might note, more often than not unimplemented in Christian societies. No society I know of approves returning a harm for a favor as a general moral rule within the group.)

Francis Fukuyama (1952- ), American political scientist, political economist, author
in The Origins of Political Order: From Prehuman Times to the French Revolution (Farrar, Straus and Giroux, 2011)