Game Theory Calls Cooperation Into Question

An anonymous reader sends this excerpt from Quanta Magazine: The physicist Freeman Dyson and the computer scientist William Press, both highly accomplished in their fields, have found a new solution to a famous, decades-old game theory scenario called the prisoner's dilemma, in which players must decide whether to cheat or cooperate with a partner. The prisoner's dilemma has long been used to help explain how cooperation might endure in nature. After all, natural selection is ruled by the survival of the fittest, so one might expect that selfish strategies benefiting the individual would be most likely to persist. But careful study of the prisoner's dilemma revealed that organisms could act entirely in their own self-interest and still create a cooperative community.

Press and Dyson's new solution to the problem, however, threw that rosy perspective into question (abstract). It suggested the best strategies were selfish ones that led to extortion, not cooperation.

[Theoretical biologist Joshua] Plotkin found the duo's math remarkable in its elegance. But the outcome troubled him. Nature includes numerous examples of cooperative behavior. For example, vampire bats donate some of their blood meal to community members that fail to find prey. Some species of birds and social insects routinely help raise another's brood. Even bacteria can cooperate, sticking to each other so that some may survive poison. If extortion reigns, what drives these and other acts of selflessness?"

Comments

Theory vs Empericism

[Wonko the Sane]

Why isn't this headline, "Game Theory Called Into Question for Failing to Predict Observed Examples of Cooperation?"

Re:Theory vs Empericism

[reve_etrange]

Why isn't this headline, "Game Theory Called Into Question for Failing to Predict Observed Examples of Cooperation?"

Unfortunately this test is all too often ignored.

Re:Theory vs Empericism

[Dorianny]

Why isn't this headline, "Game Theory Called Into Question for Failing to Predict Observed Examples of Cooperation?"

To prove that Slashdoters act selfishly to draw interest to their submissions, just as Game theory predicts.

Re:Theory vs Empericism

[bill_mcgonigle]

The Prisoners' Dilemma is a two-person example of a market failure - a term from economics which basically means that one actor can benefit from doing a thing that is bad for the group. Friedman's go-to example is people burning coal to heat their homes in 18th century London. Each homeowner _correctly_ calculated that coal was their personal best option, but it wasn't the best option for everybody, in aggregate. People who block intersections to avoid waiting for the next green are a more modern example - they save a little bit of time and make everything worse for everybody else.

The follow-up insight is that in natural systems, when rules result in a market failure, the rules slowly wind up changing to eliminate that scenario because those scenarios aren't good for the group (which is needed for reproduction/continuance) and (in the case of evolution) are selected against or (in the case of economics) are driven out of the economy.

Iterative plays resulting in extortion aren't going to be good for the group either and would tend to be eliminated. To be fair, we suffer broadly from the impact of psychopaths and they're only 5% of our population, so even if trends are good, local mischief isn't out of the question.

Re:Theory vs Empericism

[RazorSharp]

The phrase that makes me roll my eyes is "survival of the fittest." That's not what natural selection is. It's a gradual increase in variation with the death of the unfit. An organism doesn't have to be "the fittest," it just has to find an unoccupied niche. Thus the various "strategies" different organisms will take for survival -- be it cooperation, selfishness, or some combination of the two -- will vary depending on the organism.

Ants are pretty cooperative. Big cats are pretty selfish and territorial. But wild/feral horses are an interesting combination of the two. They have herds of mares with a few stallions. The stallions attack any other stallion that comes near and once a young stallion grows to a certain age they banish it from the herd. The stallions act pretty selfishly while the mares act rather cooperatively (however, they have a hierarchy so there's some selfishness involved, too).

I think the problem is trying to theorize a formula for understanding the behavior of organisms, or a most successful behavior, in general. There's just way too much diversity in nature for something like game theory to cover all its ground. Perhaps it works when you pigeon-hole it into capitalist economics, but I don't think it's a very comprehensive theory for explaining how animals do or ought to act.

Re:Theory vs Empericism

[HiThere]

You misunderstand Game Theory. Game Theory is, AFAICT, always correct. Unfortunately it's usually too difficult to calculate outside of simplified toy examples. Which is why it's used in capitalist economics, and artificially over-simplified description of how people interact. When Game Theory makes a prediction about what action will happen in capitalist economics, it's not a prescription. It merely says that if this doesn't happen, then the model you are using isn't a correct description of reality. It doesn't say it *should* be a description of reality. Unfortunately, some people, often for selfish reasons, take it as a prescription, often because taking it that way is to their benefit.

The model isn't real.

[Kaenneth]

Real Life isn't Spherical Cows. They need a better model.

Re:The model isn't real.

[Tablizer]

It is now, Americans are overweight.

Re:The model isn't real.

[Anonymous Coward]

They need a better model.

Yes, in order to get their result they put constraints on the payoffs - and they also implicitly assume that the players can't ever stop playing.

In real life, there's typically three choices: cooperate, betray, or end the relationship. Typically as people get to know each other they increase their level of cooperation up to a level that both are comfortable with. But then if there's a betrayal the other person will often permanently end the relationship - either by walking away or by hitting the other person over the head with a large rock and hiding their corpse in some bushes.

And often there's someone else waiting eagerly to cooperate with the person who got betrayed - who will help the person who got betrayed end the relationship with the betrayer - with a rock to the head if necessary.

There are probably some situations out there in nature where their model does apply. And where cooperation doesn't happen. But it would be silly to assume that their model applied to every situation in human relationships.

co-operation

[Anonymous Coward]

Sometimes the 'fittest' thing to do is to help your community because having a strong community helps you more than going it alone.

Direct link to the original paper

[mc6809e]

Iterated Prisoner's Dilemma contains strategies that dominate any evolutionary opponent

The Selfish Gene

[flyhigher]

The selfish gene theory popularized by Richard Dawkins states that evolution works on genes, not on individuals. Any gene which gives rise to behavior that will cause more copies of that gene to survive, will increase its percentage in the gene pool at large.

http://en.wikipedia.org/wiki/G...

Re:The selfish gene

[fuzzyfuzzyfungus]

Evolutionary pressure ultimately acts on genes; but (especially among species where 'horizontal gene transfer' is a weak sex joke, rather than a routine genomic reshuffling strategy), a lot of selection happens to organism-level bundles of genes, with all of them going down with the ship at the same time.

Re:The Selfish Gene

[VirginMary]

It's not pedantry! Also, if someone has no offspring but somehow contributes to the survival of others, that individual promotes the survival of the vast majority of his or her genes. The effect is even greater if the support is for offspring of close relatives. Finally, I think most people like to delude themselves with fantasies of how unique they are!

Did he read it?

[phantomfive]

[Theoretical biologist Joshua] Plotkin found the duo's math remarkable in its elegance. But the outcome troubled him. Nature includes numerous examples of cooperative behavior. For example, vampire bats donate some of their blood meal to community members that fail to find prey. Some species of birds and social insects routinely help raise another's brood. Even bacteria can cooperate, sticking to each other so that some may survive poison. If extortion reigns, what drives these and other acts of selflessness?"

I'm not sure Joshua Plotkin read the paper. It does not claim (as I understand it) to represent every scenario, merely a special case of a specific scenario. Explicitly, it requires the organism to have enough intelligence to remember what happened in previous games, so a bacteria without memory is not covered under this model. The strategy requires multiple rounds be played.

Also worth mentioning that 'good for the individual' is not the same as 'good for the species,' and nature selects the latter

I know almost nothing about vampire bats (except don't get bit, you'll need rabies shots!), but if someone understands how it relates to the prisoners' dilemma, I'd be interested in hearing it.

Re:Did he read it?

[Vintermann]

It does not claim (as I understand it) to represent every scenario, merely a special case of a specific scenario.

Freeman Dyson wouldn't be bombastic and exaggerate, would he? "Prisoner's dilemma has been solved!"

For actually intelligent strategies (and the point of strategies is that they should be intelligent), the folk theorem is the relevant solution, not this. For that matter, this seems like a weak, specific case of the folk theorem.

Nothing is possible.

[Anonymous Coward]

In other news, some people believe economic theory.

Re: Nothing is possible.

[Anonymous Coward]

It has been proven over and over that the only people who always behave according to game theory are economists and sociopaths.

Naturally we have a whole economic system based on this. People wonder why nobody's happy with it, and yet we have a population that is dumb enough to quite literally go to war for it.

Re: Nothing is possible.

[Anonymous Coward]

No. Americans are brainwashed into believing their current economic system is the only way despite the fact that it is not sustainable in the long term and is beginning to strain and fail for providing for the basic needs for nearly half the country. Then they are taught to internalize the blame for all the shortcomings of the system. If you are poor and starving it is because you are greedy and lazy, not because your formerly well paying job was outsourced to China.

Re: Nothing is possible.

[tburkhol]

Well please find an economic system that deals with the issue of sacristy, and insures its contributers exceed its detractors. At the same time insuring personal liberity.

The Kula Ring in the Trobriand Islands, where the residents of different islands developed a tradition of exchange of 'gifts,' distinct from barter-like trade. There are a number of other 'gift economies' among isolated, pre-industrial cultures. Participation is managed by social expectation and taboo, so one can argue that these systems will necessarily break down once you have enough sociopaths. One can also argue that such communities are better at recognizing and isolating sociopaths so they can't propagate their genes/behavior.

Nor is 'free market' an especially good way to deal with scarcity. If it were, then you wouldn't need social support programs. Or maybe you're going to tell me that anyone receiving social security of SNAP is not truly participating in the economy...

I don't even know where you're going with 'personal liberty.' The economic system has so little to do with what you're allowed to say, which god you're allowed to worship, or how you spend your free time as to be completely orthogonal.

Re: Nothing is possible.

[Sun]

What game theory has to say about that is to point out that these systems only work so long as the number of participants is small enough. Once the number of participants gets too large, it is impossible to effectively punish the leachers, and the entire system falls apart.

I guess we need to add to GP's original question the criteria of "works on a large scale"

Shachar

Re: Nothing is possible.

[Luckyo]

What game theory has to say about that is to point out that these systems only work so long as the number of participants is small enough. Once the number of participants gets too large, it is impossible to effectively punish the leachers, and the entire system falls apart.

I guess we need to add to GP's original question the criteria of "works on a large scale"

Shachar

This is a lie often peddled in states with this system.

There are several concrete counter-examples that prove it false, ranging from Nordic countries (which view consensus and cooperation as primary tools of both political and economic systems) as well as much bigger Japan which has more of a top down system but where bosses initially even committed honourable suicide when they had to let workers go because it was considered such a significant loss of face.

These systems exist on large scale. What they require however, is a culture that promotes selflessness rather than selfishness. In the Western countries, such culture exists in Japan and Nordics. And to a lesser extent in Germany and Scotland. All of these are functional states (with exception of Scotland) where people routinely vote for and say in polls that they are willing to pay more taxes so that those who are not viable humans can live a decent life.

Re: Nothing is possible.

[duck_rifted]

So when I'm approached with offers to make more than $10k in a few weeks because I've empirically demonstrated programming skills worth that kind of pay, but I don't get the job because I don't have a degree that cost enough, it's because I'm stupid and lazy? See, the weird thing about that is, I would have thought that spending thousands of hours practicing a cognitively intensive discipline of my own volition, and becoming adept at it, meant exactly the opposite.

I honestly would never have guessed that the words "stupid and lazy" actually mean, "doesn't have parents who can afford to pay ridiculous sums for a scrap of paper, and didn't take on unnecessarily debt." And I'm descended directly from a long line of Lord Baltimores too, so it's not even a matter of pedigree. Maybe if I were smart I'd win the lottery, right?

Today's snobs are the most vacuously interesting.

Re: Nothing is possible.

[PopeRatzo]

It has been proven over and over that the only people who always behave according to game theory are economists and sociopaths.

I don't know who you are, friend, but that's the most insightful thing I've read on the internet so far today.

Of course, it's only 6:48am and I've been up for 45 minutes, but you are correct.

Re: Nothing is possible.

[Impy the Impiuos Imp]

You live in a fantasy world where those bad things are happening.

Meanwhile, in the real, actually-measured world, things are continuing to get better decade by decade.

If the west has come close to stagnating for a bit, it's because places like China are opening up and becoming more economically free. In short, the average health and wealth of economically free people continues to increase, exactly according to Julian Simon's simple, and not really controversial in the details, model.

Re: Nothing is possible.

[Luckyo]

https://en.wikipedia.org/wiki/...

Japan finished Westernization in 1950s and is considered a "hybrid Western state" that has significant Western cultural influences while retaining much of its native heritage.

https://en.wikipedia.org/wiki/...

Re: Nothing is possible.

[Luckyo]

There is no "hijack". "Western" is an accurate descriptor often used in anthropology for societies with specific set of values sourced from Western Europe. "Westernization" is the process of exporting these values.
https://en.wikipedia.org/wiki/...

Other distinctly Western countries located in the East of globe are Australia and New Zealand for example.

Re: Nothing is possible.

[Luckyo]

First of all, I'm not at all saying that "US should change its culture". As any advanced culture you should adapt slowly with times, and absolutely not aim to "change the culture" other than for self-betterment. All I'm saying is that you should cease pretentious bullshit about how your culture is "superior" when it's obviously superior in some areas - and drastically inferior in others. And generally unfit to most of the world because of its specific focus on selfishness, which is currently heavily taxing your society to the extreme such as general ungovernability due to pandering to special interests (see - selfishness) and inability to compromise (see - winner takes it all opposition style system over consensus).

On unemployment benefits in Europe - they are small because high taxes pay for most necessities through making them free or extremely cheap. That is, universal healthcare, free education, functional subsidised infrastructure and so on. US model is essentially "pay more and subsidise little". Nordic model is "pay less and subsidise a lot". Back when I was a student on state aid for about a year I had about 100EUR after paying for bare necessities like rent and food. But I never had to be afraid of getting sick, my education was basically free, food at university was heavily subsidised, sports activities were all but free, and so on. At the same time a US student has to take heavy loans just to pay his tuition in a high quality university, or have his family assist him. Or will have to work during his studies, unable to focus on studies alone. Same thing for unemployment benefits (which are notably low in Germany because Germany is currently a de facto full employment economy and most benefits are now in process of being moved to low income part time workers instead).

Overall, your entire argument is that of a supremacist. "We are superior, others are inferior, they should just adapt our superior system over their inferior one". You're in a good company that way. Historically, most of the worst tyrannies adopted just that particular attitude. This is a sign if inferiority complex, rather than any kind of superiority.

Now for the most ridiculous part of all. "Horrendous social, cultural and economic structures Japanese live under"? Has it ever occurred to you that to them, their lives are a norm and US social, cultural and economic structures seem horrendous? Which would be because different cultures create different expectations in people, alongside different reactions to exactly same situations. What you view as "horrendous", many of those who grew in the culture view as "great" and what you view as "great" many view as "horrendous". For example, must of current European opposition to TTIP is rooted in the fact that the deal would likely force us to relax some of the state structures related to universal healthcare and allow US style profiteering on suffering of others. Because in US the social norm is that open profiteering from suffering of those poorer is completely acceptable and even encouraged: see opposition to universal healthcare "but what if my money goes to take care of someone who I don't care about". In most of Europe it's viewed as horrendous and downright monstrous and paying taxes to help those less fortunate is viewed as a civic duty and insurance for oneself in case one ends up among those less fortunate.

Just one of many massive cultural differences that show particular inferiority of US culture's way of doing things. At the same time, one should also note the superiority in other things - such as for example being better at motivating entrepreneurship, being far more tolerant of failures (in much of Europe and Japan for example, starting a company and failing is considered a black mark on one's reputation which reduces motivation of potential entrepreneurs.) It's also notably less ethnocentric and as a result notably less inherently racist (Japan is especially bad here), tends to allow for significantly greater personal freedom in certain areas and so on.

Co

The model doesn't describe the system.

[kuzb]

It's that simple. They have a neat mathematical model which is interesting, but if it doesn't make accurate predictions when applied to a more realistic scenario then it's missing something.

Re:The model doesn't describe the system.

[Black Parrot]

I think the disconnect is in expecting evolution to produce optimal solutions. Biology is full of make-do solutions.

Re:The model doesn't describe the system.

[retroworks]

The model is only as interesting as "prisoners" are defined simply by X and Ys. What if a prisoner X has a reputation for having 'defected' in similar situations? what if prisoner Y has a reputation as being a stand up guy, "honor among theives" type?

Trying to extrapolate social behavior, reasoning and evolution from such a simple model is like trying to build a house with nothing but circles and squares. It can be done, but nature observes triangles. Add a third, fourth, fifth, sixth, and seventh prisoner, put them on a lifeboat with enough food for 5 people, and try the math again.

Re:The model doesn't describe the system.

[Boronx]

From reading the actual paper, I think it describes reality pretty well. For people that want to just get by with out thinking too hard about it and just naively optimize their own gains, they'll find a cooperative strategy is better. For those who want something a bit more, they'll think about it and realize that exploitation of the cooperators is the fast track to success.

Evolution isn't about personal survival

[taustin]

It's about procreation and the survival of the genetic line. Individual survival is irrelevant, especially once one has procreated. (Though even those who don't contribute to the survival of the genetic line of their family - the person who has a sibling willing to sacrifice themselves to save the family enhances the chances the family will procreate.)

This kind of confusion is what happens when people try to do research outside of their expertise. If you want to understand biology, ask a biologist, not a physicist or a computer geek. (Though a lot of biologists make the same mistake, of course.)

The selfish gene

[leifbork]

WTF. The examples with cooperating organisms are irrelevant since evolutionary pressure acts on genes foremost, and not individuals. The question is whether the outcome with extortion would be as worrying if you apply it to genes instead.

Cooperation

[wonkey_monkey]

The physicist Freeman Dyson and the computer scientist William Press [..] have found a new solution to [...] the prisoner's dilemma

So... what you're saying is... these two guys have cooperated to call cooperation into question...

Riiight...

Re:Origin of *Species*

[ihtoit]

except it's the selfish assholes who equip themselves to guard what they have against anybody else getting it. The selfish assholes survive because they have the keys to the grain silo, everybody else (read: who hasn't got a copy of the key) can go die in a field. Selfish asshole (=selfish gene) survives, the meek inherit the Earth. From six feet beneath it.

Taking your work too seriously

[Tablizer]

The researchers were going to publish the study, but they wouldn't cooperate with the publishers.

Re:Origin of *Species*

[Shimbo]

You fall into the common error of equating the selfish gene with selfish individualism. Life is more complicated than that. There are times when protecting your family or the wider community at the risk of your own life is absolutely what is best for the survival of your genes.

And for sure, 'dove' is a lousy strategy in iterated prisoners dilemma. Hit him if he hits me first works fairly well though.

Re:Spite?

[bill_mcgonigle]

Spite often benefits the group over time - the individual sacrifices a little bit to increase the group benefit (which should be returned to him in aggregate as a non-zero-sum game). It can also benefit the individual by trading one thing of value for another in order to alter an adversary's value equation (like the legendary nuns who cut off their noses to avoid being raped by the marauders). Sometimes the costs are quite high but it's always a lesser-value for greater-value trade (as far as the individual values those things).

Re:Origin of *Species*

[rtb61]

Wasps, bees, ants, etc etc all prove you false. Reality is cooperation is genetically inherent within many species, together as a group they survive and all genes associated with that collective group survive. So with cooperative species it is not about individual genes but the shared genes within individuals that provides for the advantage of cooperation.

The entirety of you genes are absolute not unique it would be impossible to breed if that were true. So there is only a minor variability in genes with cooperative species. Consider evolution in cooperative species as being how those genes mix, match and share over generations as various parental genes are shared within that cooperative group over generations ie inbred leads to genetic failure, so the mix genetic pairings over generations incorporating more effective genetics across the whole social group over generations.

So yeah, absolutely wrong with regard to the selfish gene because it is not one breeding in cooperative groups, but shared breeding with variations in parental lineage over many generations, effectively cooperatively sharing genes within that social group.

Tit-for-tat is not ESS. It is well known.

[140Mandak262Jamuna]

In the iterative prisoners dilemma problem the tit-for-tat strategy won big in the first tournament, back in 1988, U Mich, conducted by Axelrod, won by Anatole. The biggest breakthrough of that research is to show that "it is possible for islands of cooperation to emerge in the sea of selfishness". That is all it showed, It did not show that tit-for-tat is the best under all circumstances, nor the islands of cooperation could not be snuffed out if the pay outs changed. It is also very well known it is not an evolutionarily stable strategy. It will never drive selfishness to extinction. There will always be islands of selfishness even after the population is dominated by cooperating members.

All this paper shows is, once tit-for-tat establishes a beachhead and converts the population to a largely cooperating one, other strategies will emerge that will exploit the naive cooperators. Big deal. It is very well known.

Within two generations of eradicating most viral diseases, the anti-vaccination people are back, showing that once something becomes the common wisdom, there will be incentives to be a contrarian.

Re:Tit-for-tat is not ESS. It is well known.

[david_thornley]

The advantages of tit-for-tat are that it will stay cooperative against cooperative opponents, maximizing the total gain, and that it will not lose to its other player by more than one defection. It isn't necessarily the best strategy, but it has some provable advantages.

Therefore, if this strategy, whatever the heck it is, plays against tit-for-tat, it will come out ahead by a small amount. No extortion is possible against tit-for-tat, since it has a very short memory. Any serious attempt to hurt it hurts the opponent almost as much. The outcome of the game will be determined by the opponent, but it isn't clear to me that this is good for the opponent.

In a series of games, with players changing algorithms, tit-for-tat is not particularly susceptible to extortion, since it fundamentally yields the opponent one extra defection/cooperation win. Any attempt to extort it into more than one will fail in a competitive environment, since, if tit-for-tat is trashed the opponent is trashed almost as much. Tit-for-tat against itself, or any other strategy that won't defect first, will get straight cooperation rewards, while defect-first strategies have to accept some mutual defections, lowering the total score.

So, while I'm willing to concede that the mathematics is correct (it's been a long time since I read a mathematical paper, so I haven't checked it out fully yet), it doesn't look like it's going to make much of a difference in final score.

Re:Tit-for-tat is not ESS. It is well known.

[140Mandak262Jamuna]

The telling thing about the description, (I could not get the math) is that the strategy with longer memory loses! They are using a concept of "strategy with a theory of mind". Basically it tries to predict if the other person is rational. If they think the other one is, then it pays to be irrational. It is basically a game of chicken and the player who is reckless will win against the one who is prudent.

There is some real life applications for this. Since I am a bleeding heart liberal I see the Republicans being reckless with government shutdowns and pushing the envelop on filibusters etc as this "I will first show you I am reckless then let us play chicken". (If you are a Republican you might strongly disagree with this example).

I also see this as the explanation for being reckless revenge and disproportional response. Typically in India riots would erupt on the rumor Some boys of set A teased some girls of set B. The sets could be caste, religion, language. In the over the top response for something minor the riot inciting group suffers as much damage as all others. It is totally irrational. But the purpose is to set the stage for others for all future interactions, "Malabar Muslims or Dharavi Tamils or Biharis are known to be violent. Be more careful around them".

Or like John McEnroe's tantrums in the tennis matches is to intimidate the line judges into giving him the benefit of doubt in the future calls.

So the theory is not without its merits. But, as usual, the title is more provocative than warranted.

A prisoner's actual dilemma

[Livius]

In real life, which so many experts seem uninterested in, the participants in the prisoner's dilemma need to keep quiet until they've talked to a lawyer.