
Game Theory Calls Cooperation Into Question - droque
https://www.quantamagazine.org/20150212-game-theory-calls-cooperation-into-question/
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hyperion2010
Rather amusing title since it could be reworded as "Game theory still fails to
explain biology." We know organisms cooperate. The fact that we consistently
fail to find reasons to cooperate in game theory suggests that the simplifying
assumptions that it makes are incorrect. To give only one example, what
happens when agents can choose from among a set of games to play with
opponents with known histories?

~~~
KingMob
Exactly correct. Why play with cheaters?

The fundamental flaw in applying game theory to biology is to constrain the
possible outcomes when unfairness is detected. In game theory, all you can do
is change your strategy for the next round; in reality, we have multiple
punishments to bring to bear, such as refusing to play, public shaming, fines,
imprisonment, killing, etc.

Game theory is only an "ok" model of cooperation/competition in real life.

~~~
elektronjunge
That's not a problem with game theory. That's a problem with using overly
simplistic games. You can easily model all of those punishments with different
payouts in a game. In fact, when I studied it in school most of the games we
worked through included punishment mechanisms.

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forkandwait
Perhaps "cooperation brings game theory into question" would be a better
title?

~~~
HarryHirsch
You can't upvote this enough. If the predictions of your model don't square up
with reality, reality that came into being through evolution on the geological
timescale, it's time that you should look at the shortcomings of your model.
Perhaps _it_ can evolve into something with actual predictive value.

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klochner
Many people seem to have game theory backward.

Game theory is a modeling tool that assumes all relevant utility is baked into
the payoff matrix.

Games (payoff matrices) that capture unique outcomes/behaviors are often given
memorable names from human situations that approximate the games. For example
the matrix referred to as 'prisoners dilemma' demonstrates a situation where
dominant actions give a suboptimal outcome. In describing where this game may
apply, economists found simultaneous interrogations to be a colorful and close
enough approximation to the idealized game.

It's _not_ the case that game theorists started with the situation of
interrogating prisoners and ended up with the game matrix.

Similarly, for anyone saying that 'that wouldn't happen in real life', you're
actually saying that the payoffs don't accurately model the outcomes.

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raverbashing
> Game theory is a modeling tool that assumes all relevant utility is baked
> into the payoff matrix.

Correct, and they mostly use the prisioner's dilemma, which is very
simplistic, and probably not what it happens in nature (or common situations)
most of the time.

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nosuchthing
Pack animals like dogs naturally discourage fighting amongst themselves [1].
Strife weakens the pack.

Consider the effort it takes 1 person to build a house, or the amount of
effort it would take to build an mp3 player alone from scratch.

Game theory would have you believe the optimal way to win at poker is to booby
trap the card table and rob your competition.

[1]
[https://www.youtube.com/watch?v=hstLdzCg6l8](https://www.youtube.com/watch?v=hstLdzCg6l8)

~~~
elektronjunge
Correct and there are games that model that behavior, for instance iterated
stag hunt[1]. This shows the benefits of cooperation for pack animals much
more than the classic prisoner's dilemma. Of course you could construct a more
detailed game that includes factors like defense and having a single leader
that would be even closer to reality. The math behind game theory is right,
its a question of whether we have chosen the right game to play.

[1]
[http://en.wikipedia.org/wiki/Stag_hunt](http://en.wikipedia.org/wiki/Stag_hunt)

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vacri
_A monkey will scream to warn its neighbors when a predator is nearby. But in
doing so, it draws dangerous attention to itself. Scientists going back to
Darwin have struggled to explain how this kind of altruistic behavior
evolved._

Seriously, this is not that hard. If the prey is relatively mobile, for most
predators the gig is up if the prey is aware of them. If the prey is alerting
it's friends that a predator is around, then that particular animal has seen
the predator and is usually therefore relatively safe from it. For example, if
an angry dog is barrelling towards your unsuspecting friend, shouting out may
draw attention towards you, but you can shout and take countermeasures at the
same time. It's not a zero-sum game, and you don't need hundreds of iterations
to make it beneficial to yourself. I mean, hell, watch a random Attenborough
nature special, and you're likely to hear him talk about the prey spotting the
predator, leading to an abandonment of the hunt.

The strange maths continues with the "Bat's Dilemma" example. In the case
where both bats do the same thing, share or not share, there are disconcordant
outcomes. Same population of bats, same amount of food available, yet somehow
there is much more hunger if they don't share. This would only make sense if
each bat only occasionally had a meal from a source which was much larger than
it could eat by itself, then had a long period without finding food... in
which case, sharing the excess really isn't a dilemma, since it's excess. I
really don't understand the maths in that example.

Game theory really does seem to be a hammer desperately searching for anything
that looks like it might possibly be a nail. It is interesting that the end of
the article says it has some suitability for microbe research, where things
are much more stimulus/response and much less complex.

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D_Alex
> In a single instance of the prisoner’s dilemma, the best strategy is to
> defect — squeal on your partner and you’ll get less time.

No, that is not right, if it was there would be no dilemma, and this subject
would not be discussed ad nauseam. The whole point is that the situation is
symmetrical for both players, _they should reach the same conclusion and act
the same way_... and using the strategy of cooperation their outcome is better
than defecting.

~~~
crander
Cooperating is strongly dominated by defecting in Prisoners Dilemma. This is
an obvious and very basic game theory result.

Game Theory models strategic situations and doesn't offer insight outside what
is modeled. If you think there should be communication supporting cooperation
in the game, that game is NOT the Prisoners Dilemma and is in fact another
game.

The Prisoners Dilemma is a model that is stacked very much against
cooperation. Think about it, the prisoners are held in separate rooms and not
allowed to communicate at all in the original story.

~~~
yarrel
Iterated Prisoners dilemma is less clearly stacked in favour of defecting,
although I assume that the actors' memories would fall under "communication":

[http://en.wikipedia.org/wiki/Prisoner%27s_dilemma#The_iterat...](http://en.wikipedia.org/wiki/Prisoner%27s_dilemma#The_iterated_prisoners.27_dilemma)

~~~
crander
Yes, a repeated game like Iterated PD is a different game with a different
solution. The Grim strategy for example.

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tunesmith
The question I was left with is, what conditions do you introduce into an
evolving population that make cooperation more beneficial than extortion? They
talked about just introducing random conditions or mutations but I wonder if
the ones that led to (cooperation beating extortion) had any sort of pattern.

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kriro
The most interesting point that was glanced at in the article from my point of
view is that small changes in conditions lead to big changes regarding optimal
strategy. My chaos theory is a little flimisy but I think conceptually a
general framework of considering optimal strategies as strange attractors
makes sense.

In fact I think it's more interesting to find the systems in which a given
strategy is successfull as opposed to finding a successfull strategy given the
system. There's all sorts of interesting questions that arise from this point
of view the most obvious one being how does one (or animal populations) change
the inputs that form the system in such a way that it leads to the given
strategy being successfull.

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mslot
Evolution happens primarily in spurts with high selection pressure in which
cooperation probably makes less sense than in stable populations with
relatively low selection pressure.

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pasbesoin
Yes, this is a quip:

Carrot and stick: The two poles of community (of the community magnet).

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barry-cotter
>Researchers have proposed different possible mechanisms to explain
cooperation. Kin selection suggests that helping family members ultimately
helps the individual.

This is wrong and should significantly reduce any trust you may have had in
the journalist who wrote the piece. Kin selection is about how helping family
members helps the genes that make the individual. Behaviour will spread if it
increases inclusive fitness. If you can save a sibling (coefficient of
relatedness 0.5) with probability 1 and the chance of you dying is 0.4 you do
it. If P(death) is 0.51 or higher you don't.

>Group selection proposes that cooperative groups may be more likely to
survive than uncooperative ones.

The conditions necessary for group selection are incredibly strong and very
rarely occur in practice in biological settings. When they do you get hive
organisms like naked mole rats or the Hymenoptera. There is stronger evidence
for group selection in cultural evolution than in most of biology.

Further reading
[http://lesswrong.com/lw/kw/the_tragedy_of_group_selectionism](http://lesswrong.com/lw/kw/the_tragedy_of_group_selectionism)

>“As mutations that increase the temptation to defect sweep through the group,
the population reaches a tipping point,” Plotkin said. “The temptation to
defect is overwhelming, and defection rules the day.”

>Plotkin said the outcome was unexpected. “It’s surprising because it’s within
the same framework — game theory — that people have used to explain
cooperation,” he said. “I thought that even if you allowed the game to evolve,
cooperation would still prevail.”

>The takeaway is that small tweaks to the conditions can have a major effect
on whether cooperation or extortion triumphs. “It’s quite neat to see that
this leads to qualitatively different outcomes,” said Jeff Gore, a
biophysicist at the Massachusetts Institute of Technology who wasn’t involved
in the study. “Depending on the constraints, you can evolve qualitatively
different kinds of games.”

Mathematicians develop model that gives us a deeper understanding of the
shallowness of our understanding of cooperation.

Unfortunately my math isn't strong enough to understand the paper but you'll
get a much better understanding of how game theory applies to biology from
_The Selfish Gene_ by Richard Dawkins than from this article.

Don't read anything by Stephen Jay Gould
[http://pleiotropy.fieldofscience.com/2009/02/krugman-on-
step...](http://pleiotropy.fieldofscience.com/2009/02/krugman-on-stephen-jay-
gould.html)

[http://en.wikipedia.org/wiki/Stephen_Jay_Gould#The_Mismeasur...](http://en.wikipedia.org/wiki/Stephen_Jay_Gould#The_Mismeasure_of_Man)
In 2011, a study conducted by six anthropologists reanalyzed Gould's claim
that Samuel Morton unconsciously manipulated his skull measurements,[82] and
concluded that Gould's analysis was poorly supported and incorrect. They
praised Gould for his "staunch opposition to racism" but concluded, "we find
that Morton's initial reputation as the objectivist of his era was well-
deserved."[83] Ralph Holloway, one of the co-authors of the study, commented,
"I just didn't trust Gould. ... I had the feeling that his ideological stance
was supreme. When the 1996 version of 'The Mismeasure of Man' came and he
never even bothered to mention Michael's study, I just felt he was a
charlatan."[84] The group's paper was reviewed in the journal Nature, which
recommended a degree of caution, stating "the critique leaves the majority of
Gould's work unscathed," and notes that "because they couldn't measure all the
skulls, they do not know whether the average cranial capacities that Morton
reported represent his sample accurately."[85] The journal stated that Gould's
opposition to racism may have biased his interpretation of Morton's data, but
also noted that "Lewis and his colleagues have their own motivations. Several
in the group have an association with the University of Pennsylvania, and have
an interest in seeing the valuable but understudied skull collection freed
from the stigma of bias."

