On Sun, 26 Apr 2015 22:50:03 -0700 (PDT), John Ladasky <john_lada...@sbcglobal.net> wrote:
>On Sunday, April 26, 2015 at 6:41:08 PM UTC-7, Seymore4Head wrote: > >> Richard Dawkins explains with passion the idea of game theory and tit >> for tat, or why cooperation with strangers is often a strong strategy. >> >> He talks of a computer program tournament. I don't know what I could >> say that would be more interesting than just watching the video. > >Well, I'm not sure sure what any of this has to do with Python -- but since I >know something about the subject, I'll reply. > >That Richard Dawkins video is quite old -- it would appear to be from the >middle 1980's. Douglas Hofstadter's 1985 book, _Metamagical_Themas_, covered >this exact same material. A game called the "Iterated Prisoner's Dilemma" is >played (I'll abbreviate it as IPD). Humans can play, of course, but in this >case it is played by algorithms. An algorithm called "Tit for Tat" is >surprisingly simple and robust. When meeting a new contestant, Tit for Tat >plays nice in round 1; and on every subsequent round, it plays however that >opponent played the last time. > >Evolutionary biologists like Dawkins point to the success of Tit for Tat in >IPD as a model of how cooperation could emerge in a population of selfish >organisms. Now, in a round-robin IPD game, Tit for Tat wins pretty handily. >But in some other scenarios, as I recall, Tit for Tat is not a runaway winner. > >Suppose that instead of each strategy playing EVERY other, each strategy >inhabits a "territory" in a space, and each strategy only plays its neighbors. > In "rough neighborhoods", Tit for Tat can lose out to more punitive >strategies. If Tit for Tat is around more cooperative strategies, it thrives. > The boundaries between good neighborhoods and bad are chaotic. Tit for Tat >more or less holds the borders, but usually can't clean out a bad neighborhood. > >This finding came out many years after the Hofstadter and Dawkins reports, so >it's not covered in the video. My reference to the idea is a 1997 paper >entitled "The Undecidability of the Spatialized Prisoner's Dilemma," by >Patrick Grim (http://link.springer.com/article/10.1023%2FA%3A1004959623042). In the past, I have had some measure of success with the Toot for Tail strategy. -- https://mail.python.org/mailman/listinfo/python-list
