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Resilient cooperators stabilize long-run cooperation in Prisoner’s Dilemma

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Re: Resilient cooperators stabilize long-run cooperation in Prisoner’s Dilemma

#41

Post by mizzao »

diziet wrote: post #40
mizzao wrote: post #21

Lead author of the paper here; AMA. The main novelty about this work is that we had 100 people play repeated PD for a month instead of The findings can be summarized in a sentence as "a minority of nice people can make everyone better off."

Were conditional cooperators playing a tit-for-tat strategy or something different? I see you citing Axelrod and Rapoport but after reading through most of the supplementary material exit questions, I most often saw descriptions similar to “I chose to cooperate unless the other person chose the defect at which point I chose to defect too for the rest of the game.” Also, how often is the number of rounds known in stud…

First, hat tip to you for getting to those questions. Usually no one looks at the supplementary material at all.

So the cooperators' strategy looks like tit-for-tat, but I don't think it really is because tit for tat means if someone started cooperating again after defecting, they would switch. We think it's actually a strategy where if you get defected on, you just stop cooperating altogether in the future (at least for this length of a game). However, because we never see people switch back to cooperating after defecting (after the first day where people are trying random things), we can't distinguish between these two strategies. But effectively it doesn't really matter.

A game with a finite number of rounds is a finitely repeated PD, for which the NE is to all defect. An undetermined number of rounds is ~= an infinitely repeated PD with a discount factor, for which there are many ways to sustain cooperation according to the theory.

Re: Resilient cooperators stabilize long-run cooperation in Prisoner’s Dilemma

#42

Post by mizzao »

espeed wrote: post #39
mizzao wrote: post #33

Earlier quoted context omitted.

Really cool suggestions - they actually encompass a couple of ideas that we've had. First, we discovered in the experiment that PD actually has 3 actions. Cooperate, defect, and ... wait as long as possible to defect to punish your opponent who is not cooperating. This happened because participants are playing in a real-time web app, and they have some time to make a decision. Although there is a lot of literature on…

Are you familiar with Jonathan Haidt's work on the psychology of morality and the formation of superorganisms? https://en.wikipedia.org/wiki/Jonathan_Haidt NB: Also see this timely post on "information theory and the foundations of life" https://news.ycombinator.com/item?id=13496133

I've read some of Haidt's work but not that one in particular. Thanks for the pointer.

Re: Resilient cooperators stabilize long-run cooperation in Prisoner’s Dilemma

#43

Post by mizzao »

visarga wrote: post #20
MarkMc wrote: post #5

It seems to me that in countries with systemic corruption there is a huge game of prisoner's dilemma being played, with everyone making the 'wrong' decision. Here's a fascinating quote from a book about Kenyan graft [1]: -------------------- Where does each individual draw the limits of his or her compassion, beyond which duties of kindness, generosity and personal obligation no longer apply? I was raised in a househ…

Great post and wonderfully illustrated! The prisoner dilemma also ties into the tragedy of the commons: when multiple players decide to defect and exploit the commons to the fullest, then commons lose their value for all. It is also related to temporal discounting - we prefer to pollute today and ignore the price tag we will face in the future. We know so much about game theory yet we can't apply it in politics, beca…

The n-player PD is also known as the public goods game, and is used to study cooperation as well.

Another meta-conclusion I would draw from our paper is that current game theory is insufficient to explain what we observe in real life, including politics, negotiation, and so on. It is folly to apply hyperrationality (strict economic modeling) to real human behavior, and part of the goal of our work is to stimulate more realistic models of what people do in these situations.

Re: Resilient cooperators stabilize long-run cooperation in Prisoner’s Dilemma

#44

Post by espeed »

mizzao wrote: post #42
espeed wrote: post #39

Earlier quoted context omitted.

Are you familiar with Jonathan Haidt's work on the psychology of morality and the formation of superorganisms? https://en.wikipedia.org/wiki/Jonathan_Haidt NB: Also see this timely post on "information theory and the foundations of life" https://news.ycombinator.com/item?id=13496133

I've read some of Haidt's work but not that one in particular. Thanks for the pointer.

Here is one of Haidt's TED talks that touches on these ideas, cooperation, group selection, and the free-rider problem:

http://www.ted.com/talks/jonathan_haidt_humanity_s_stairway_...

Also this Edge article on "Contingent Superorganism" https://www.edge.org/response-detail/10386

Re: Resilient cooperators stabilize long-run cooperation in Prisoner’s Dilemma

#45

Post by matchagaucho »

espeed wrote: post #32
mizzao wrote: post #21

Lead author of the paper here; AMA. The main novelty about this work is that we had 100 people play repeated PD for a month instead of The findings can be summarized in a sentence as "a minority of nice people can make everyone better off."

What if you modify the game a bit...? Give players the ability to remember players they have engaged with and add a third option: 1. Cooperate 2. Defect 3. Wait (defer, don't engage, don't play). New players will seek out players and offer to engage with them. When you defect, your reputation history declines, and when you die, your reputation history resets to zero and you lose the option to defer. HYPOTHESIS: Coope…

"Forgive but never forget".

The 3rd option used most widely in business today. Defectors are "punished" by refusing to do business with them after a defection.

Re: Resilient cooperators stabilize long-run cooperation in Prisoner’s Dilemma

#46

Post by espeed »

mizzao wrote: post #33
espeed wrote: post #32

Earlier quoted context omitted.

What if you modify the game a bit...? Give players the ability to remember players they have engaged with and add a third option: 1. Cooperate 2. Defect 3. Wait (defer, don't engage, don't play). New players will seek out players and offer to engage with them. When you defect, your reputation history declines, and when you die, your reputation history resets to zero and you lose the option to defer. HYPOTHESIS: Coope…

Really cool suggestions - they actually encompass a couple of ideas that we've had. First, we discovered in the experiment that PD actually has 3 actions. Cooperate, defect, and ... wait as long as possible to defect to punish your opponent who is not cooperating. This happened because participants are playing in a real-time web app, and they have some time to make a decision. Although there is a lot of literature on…

One way to set the stage for a "wait/defer" option would be to remove the limit of 10 rounds per game by using random time length games where players don't know how long the game will last or how many rounds it will be. Playing more successful rounds would mean more points so this should incentivize cooperators to cooperate fast without waiting/deferring if they have confidence in the other player, and it reduces the incentive to try and game the last rounds.

To add the option to "wait/defer", you could include informational incentives/variance where players gain the ability to increase their perspective and degrees of freedom by being privy to more information sooner. For example, once a player achieves some level of points/reputation, they gain the ability to see the other player's move before they move -- this would in effect be giving them the power to defer. The other player may or may not know the extent of the other player's abilities at that time -- one or both may have the ability to see (defer), and neither may know for sure. For example, rather than explicitly stating upfront to new players that through their play they can improve their ability to see, let players discover this once they cross a threshold. Further increased powers might include the ability to see into the other player's past games, see their group's dynamics or portions of the wider network, and communicate with other group members and/or the other player during games.

As stated by Axelrod in EoC, one feature of the tit-for-tat strategy is that it's easy enough that it can be understood by anyone, and it's simple enough that it can be communicated/signaled from one player to the other through their play. It would be interesting to see how learned players -- who have gained the ability to see -- use or abuse their elevated powers of sight, either by working to better signal/communicate their intent and teach the winning strategy to the less enlightened players or by choosing to try and exploit the naivety of the other player who may be relatively blind.

Re: Resilient cooperators stabilize long-run cooperation in Prisoner’s Dilemma

#47

Post by thilmo »

oli5679 wrote: post #7

In case anyone wants a primer on the prisoner's dilemma: Suppose both you and a partner get arrested whilst trying to rob a bank. Without a confession from one of you, the police can only convict you of a minor offense (say trespassing). The police place you in different cells, and offer you both the following bargain. If you confess to the robbery, and your partner does not, you get a complete pardon, and your partn…

When I was a kid and I read about the Prisoner's dilemma in the context of morality, I was always confused. Surely the moral thing is to confess if you're guilty. If you're guilty, and your accomplice is guilty, the right thing to do is confess to the police so that you can be rightfully punished.

As an adult I understand that this isn't the point of the story, and the police-and-prisoners aspect of the story is completely extraneous to the point trying to be made. Still, I can't help but think that the police-and-prisoners is a bad example of the broader point, since there's always a third set of interests (that of the police, and of society in general) which is callously (and immorally) tossed aside in the phrasing of the problem.

Re: Resilient cooperators stabilize long-run cooperation in Prisoner’s Dilemma

#48

Post by aarghh »

mizzao wrote: post #21

Lead author of the paper here; AMA. The main novelty about this work is that we had 100 people play repeated PD for a month instead of The findings can be summarized in a sentence as "a minority of nice people can make everyone better off."

The most hopeful thing I have seen all week. On a slightly whimsical note, are you familiar with the legend of Lamed Vavniks from the Talmud? From the wikipedia article: "It is said that at all times there are 36 special people in the world, and that were it not for them, all of them, if even one of them was missing, the world would come to an end." https://en.wikipedia.org/wiki/Tzadikim_Nistarim

Re: Resilient cooperators stabilize long-run cooperation in Prisoner’s Dilemma

#49

Post by Nomentatus »

thilmo wrote: post #47
oli5679 wrote: post #7

In case anyone wants a primer on the prisoner's dilemma: Suppose both you and a partner get arrested whilst trying to rob a bank. Without a confession from one of you, the police can only convict you of a minor offense (say trespassing). The police place you in different cells, and offer you both the following bargain. If you confess to the robbery, and your partner does not, you get a complete pardon, and your partn…

When I was a kid and I read about the Prisoner's dilemma in the context of morality, I was always confused. Surely the moral thing is to confess if you're guilty . If you're guilty, and your accomplice is guilty, the right thing to do is confess to the police so that you can be rightfully punished. As an adult I understand that this isn't the point of the story, and the police-and-prisoners aspect of the story is com…

But the problem has to explicitly exclude altruistic behavior; since if both subjects view the consequences to the other subject as being roughly as serious as consequences to themselves, there's no dilemma at all. They both shut up and help each other. The whole point is to show a situation exists in which two purely rational, purely selfish actors get an outcome that's actually worse for them from a selfish point of view than the outcome that two altruistic or irrational players would get. That they are criminals "establishes", to use the story-telling term, that these subjects are (unusually) not altruistic at all - the punchline is that being self-serving turns out not so well for them.

Re: Resilient cooperators stabilize long-run cooperation in Prisoner’s Dilemma

#50

Post by Nomentatus »

visarga wrote: post #20
MarkMc wrote: post #5

It seems to me that in countries with systemic corruption there is a huge game of prisoner's dilemma being played, with everyone making the 'wrong' decision. Here's a fascinating quote from a book about Kenyan graft [1]: -------------------- Where does each individual draw the limits of his or her compassion, beyond which duties of kindness, generosity and personal obligation no longer apply? I was raised in a househ…

Great post and wonderfully illustrated! The prisoner dilemma also ties into the tragedy of the commons: when multiple players decide to defect and exploit the commons to the fullest, then commons lose their value for all. It is also related to temporal discounting - we prefer to pollute today and ignore the price tag we will face in the future. We know so much about game theory yet we can't apply it in politics, beca…

>> "We know so much about game theory yet we can't apply it in politics" Oh, but we do apply this to politics, constantly; laws a re passed and enforced precisely to short-circuit a great many PDs; since if there's a large external penalty (even if infrequently applied) then short cuts may not pay. We tax everyone set amounts rather than ask nicely for contributions because that would set up a free-rider PD, etc, etc.

Of course, many political situations also exist where companies donate heavily and then ask for such penalties to be removed so they can sell worthless securities or not have their emissions monitored anymore. Democracy turns out to be pretty thoroughly corruptible, (but so do other forms of government.)

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