Nice organisms finish first: Why cooperators always win in the long run

Aug 01, 2013
"We found evolution will punish you if you're selfish and mean," said lead author Christoph Adami, MSU professor of microbiology and molecular genetics. Credit: G.L. Kohuth

Leading physicists last year turned game theory on its head by giving selfish players a sure bet to beat cooperative players. Now two evolutionary biologists at Michigan State University offer new evidence that the selfish will die out in the long run.

"We found evolution will punish you if you're selfish and mean," said lead author Christoph Adami, MSU professor of microbiology and molecular genetics. "For a short time and against a specific set of opponents, some selfish organisms may come out ahead. But selfishness isn't evolutionarily sustainable."

The paper "Evolutionary instability of Zero Determinant strategies demonstrates that winning isn't everything," is co-authored by Arend Hintze, molecular and microbiology research associate, and published in the Aug. 1, 2013 issue of Nature Communications.

Game theory is used in biology, economics, political science and other disciplines. Much of the last 30 years of research has focused on how cooperation came to be, since it's found in many forms of life, from single-cell organisms to people.

Researchers use the prisoner's dilemma game as a model to study cooperation. In it, two people have committed a crime and are arrested. Police offer each person a deal: snitch on your friend and go free while the friend spends six months in jail. If both prisoners snitch, they both get three months in jail. If they both stay silent, they both get one month in jail for a lesser offense. If the two prisoners get a chance to talk to each other, they can establish trust and are usually more likely to cooperate because then both of them only spend one month in jail. But if they're not allowed to communicate, the best strategy is to snitch because it guarantees the snitcher doesn't get the longer jail term.

The game allows scientists to study a basic question faced by individuals competing for limited resources: do I act selfishly or do I cooperate? Cooperating would do the most good for the most individuals, but it might be tempting to be selfish and freeload, letting others do the work and take the risks.

In May 2012, two leading physicists published a paper showing their newly discovered strategy – called zero-determinant—gave selfish players a guaranteed way to beat cooperative players.

"The paper caused quite a stir," said Adami. "The main result appeared to be completely new, despite 30 years of intense research in this area."

Adami and Hintze had their doubts about whether following a zero determinant strategy (ZD) would essentially eliminate cooperation and create a world full of selfish beings. So they used high-powered computing to run hundreds of thousands of games and found ZD strategies can never be the product of evolution. While ZD strategies offer advantages when they're used against non-ZD opponents, they don't work well against other ZD opponents.

"In an evolutionary setting, with populations of strategies, you need extra information to distinguish each other," Adami explained.

So ZD strategies only worked if players knew who their opponents were and adapted their strategies accordingly. A ZD player would play one way against another ZD player and a different way against a cooperative player.

"The only way ZD strategists could survive would be if they could recognize their opponents," Hintze added. "And even if ZD strategists kept winning so that only ZD strategists were left, in the long run they would have to evolve away from being ZD and become more cooperative. So they wouldn't be ZD strategists anymore."

Both Adami and Hintze are members of the BEACON Center for the Study of Evolution in Action, a National Science Foundation Center that brings together biologists, computer scientists, engineers and researchers from other disciplines to study evolution as it happens.

The research also makes that case that communication and information are necessary for cooperation to take place.

"Standard game theory doesn't take communication into account because it's so complicated to do the math for the expected payoffs," Adami explained. "But just because the math doesn't exist and the general formula may never be solved, it doesn't mean we can't explore the idea using agent-based modeling. Communication is critical for cooperation; we think communication is the reason cooperation occurs. It's generally believed that there are five independent mechanisms that foster cooperation. But these mechanisms are really just ways to ensure that cooperators play mostly with other cooperators and avoid all others. Communication is a universal way to achieve that. We plan to test the idea directly in yeast cells."

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antialias_physorg
1.7 / 5 (6) Aug 01, 2013
But selfishness isn't evolutionarily sustainable

I'd beg to differ. If the selfishness leads to the extinction of the unselfish opposition then it certainly is a winning strategy. Only if there is an 'unkillable' pool of unselfish individuals does the theory work. ZD may not 'work well' when all the unselfish ones have been eliminated, but evolution doesn't care about "works well". It only cares about "works best of all those currently playing the game" (e.g. that is why plants, despite billions of years of evolution, still only have 3% efficient photosynthesis)

On the whole that is the part about evolution that is (often) not represented in games theory scenarios. Evolution tends to do things like change the rules, eliminate one player (species), or move ones' own species to a different game every now and then.

(Still: game theory is very applicable. Not knocking game theory research, here)
drhoo
2.3 / 5 (3) Aug 01, 2013
A group of individuals that band together and cooperate is at an advantage over a group of selfish opponents.
The cooperation works as long as the unselfish individuals remain cohesive.
But if they in fight the advantage is lost.
Hmm.. any parallels to US politics come to mind.
ryggesogn2
1 / 5 (10) Aug 01, 2013
parallels to US politics come to mind.

Depends upon what they are fighting about.
If the goal of one faction, socialists, is to dominate and coerce then those who do not want to be controlled must fight to defeat or escape from the socialists.
TheGhostofOtto1923
1 / 5 (4) Aug 01, 2013
This is more support for tribalism.

"There can be no doubt that a tribe including many members who, from possessing in a high degree the spirit of patriotism, fidelity, obedience, courage, and sympathy, were always ready to give aid to each other and to sacrifice themselves for the common good, would be victorious over most other tribes; and this would be natural selection" (Darwin, 1871)"

-As well as the inclusive fitness dawkins described in 'the selfish gene:

"From the gene-centred view follows that the more two individuals are genetically related, the more sense (at the level of the genes) it makes for them to behave selflessly with each other. Therefore the concept is especially good at explaining many forms of altruism...An organism is expected to evolve to maximize its inclusive fitness—the number of copies of its genes passed on globally (rather than by a particular individual)."
alanrlight
5 / 5 (1) Aug 01, 2013
Interesting - but I can see how an equilibrium of selfish and unselfish players may eventually result, and even selfish and unselfish instincts within individuals. The selfish bits would remain in order to counteract the selfish bits in others - while cooperation would be the norm and would even benefit from the protection offered by the arrangement. Over time the equilibrium might gradually shift towards more cooperation.
nowhere
5 / 5 (1) Aug 01, 2013
Leading physicists last year turned game theory on its head by giving selfish players a sure bet to beat cooperative players.


Adami and Hintze had their doubts about whether following a zero determinant strategy (ZD) would essentially eliminate cooperation and create a world full of selfish beings.


Could someone please explain how these two points are at odds? The first point only states that a selfish player(SP) would beat a cooperative player(CP), however as more SP emerge the pairing probability would shift from SP-CP to SP-SP, which cannot exist. Either both of the SP-SP pairing would perish or one or both would convert to CP. A shifting ratio would form, with neither side claiming victory, which is consistent with both points quoted.
Gmr
1 / 5 (7) Aug 01, 2013
Essentially what we have here is ... a failure to communicate.

Populations have to procreate at some level, and regardless of whether or not there is pairing or divisive reproduction, the question of progeny survival arises. In larger organisms, adults have a size and experience benefit over newborns. If all are selfish, only the swiftest young survive the onslaught of adult selfishness. Then in larger organisms and in gene exchanging smaller ones there is the problem of cooperating to swap data.

If you leave out these considerations, sure you can have 100% bastards. Factor them in, and it is doubtful a totally selfish organism would survive even one generation.
Gmr
2.3 / 5 (11) Aug 01, 2013
Why isn't one of the effects of Dense EtheR Ptheory to stop you from posting on articles without even the loosest association with your pet meme?

You do realize it controls you now, isolating you from others by causing you to obsess, forcing you to attempt to replicate it at even the most remote opportunity?

My goodness - Dense EtheR Ptheory is actually a linguistic form of the zombie ant fungus!
Torbjorn_Larsson_OM
1 / 5 (1) Aug 02, 2013
"While ZD strategies offer advantages when they're used against non-ZD opponents, they don't work well against other ZD opponents."

As I remember it this was already known to happen on an individual level. A tit-for-tat with slight forgiveness strategy can beat a ZD strategy by emulating the ZD tactics.

@drhoo: In non-evolutionary situations, a mob rule can beat tit-for-tat individuals, but only slightly. In real life, we have legislation (in theory) preventing such criminal hoarding.

In evolutionary theory, the selfish gene strategist always wins. It is just that in some situations the vehicle, the population, behaves altruistically to ensure the selfish win.
ForFreeMinds
1 / 5 (7) Aug 03, 2013
Applying this to US politics, one might say the cooperating group are those who believe in individual responsibility and freedom, vs. the "selfish and mean" group that prefer to use government force to benefit themselves at the expense of others (say by voting themselves benefits from the treasury). After all, research shows that conservatives are bigger charitable givers than liberals who believe in less freedom. Yet liberals claim conservatives are the "selfish and mean" group because they don't support forced government redistribution of wealth.

Or applying it to countries, we might say that those countries whose institutions support voluntary cooperation, vs. countries ruled by dictators or where, instead of freedom and individual responsibility, the government takes the responsibility and freedom away from individuals, reducing them to mere slaves to government, we might expect to see that countries supporting freedom last longer, while in the others, political turmoil reign.
kochevnik
1 / 5 (9) Aug 03, 2013
@FromFriedMinds Applying this to US politics, one might say the cooperating group are those who believe in individual responsibility and freedom, vs. the "selfish and mean" group that prefer to use government force to benefit themselves at the expense of others (say by voting themselves benefits from the treasury). After all, research shows that conservatives are bigger charitable givers than liberals who believe in less freedom. Yet liberals claim conservatives are the "selfish and mean" group because they don't support forced government redistribution of wealth.


MIT Study proves Contrary To Popular Belief Conservaturds Do NOT Give More To Charity Than Liberals. But they brag much more about it
cmn
5 / 5 (1) Aug 03, 2013
So, what's this got to do with physics?
Gmr
1 / 5 (7) Aug 04, 2013
Well, the density fluctuations of gas sorta cooperate too. When they form a larger objects, then they can indeed live longer. But such large fluctuation is evolving and moving slower accordingly. When the critical size is reached, then the speed of their evolution becomes too low with compare to these smaller, more competitive and vital fluctuations and the whole selection process repeats again. Which is why the most intelligent objects in the Universe (we?) are existing at the middle of the dimensional scale of the observable Universe - not at its very end.


Oh blarg. Really, blarg. Populations of individual animals are not density fluctuations. Unless you mean between my solid mass and air, in which case I say "fie" instead of "blarg." The use of the word "vital" really seals it.

So I say, in all, "blarg," "fie," and "garg!"
Gmr
1.5 / 5 (8) Aug 04, 2013
Of course it isn't - but it can be modeled so. For example the population flows from areas of higher social pressure to areas of lower social pressure like the gas. Why not to read http://physik.uni...stem.pdf first?

Except it doesn't. Society doesn't flow like a gas. Not at all. "Social pressure" is a mock term without context, misinterpreted for its re-use in this social eddies conjecture.

What part of it flows like a gas? Its entrenchment in tradition? Its mutation into laws and local punitive structures? Its hierarchical structure? Its bifurcation in some cases into have and have-nots, as in oppressive sexist or racist or classists structures? Its "expansion" into political modes?

Please, do something more than telling me to read and giving vague purposefully blurry proto-concepts based on word-play.

Oh, and "Blarg fie garg fie garg-blarg!"
Ducklet
1 / 5 (4) Aug 04, 2013
There's no conflict between competition and cooperation; competition essentially is over who will be the best cooperator. Be it hiring or purchasing; once the negotiation stage is done the actual activity engaged in is cooperative in nature. Someone who can't cooperate will not be competitive, because they will have nothing to offer.