

Chimps outperform humans in simple contests drawn from game theory - fraqed
http://phys.org/news/2014-06-strategy-chimp.html

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soneca
I didn't understand two things, if someone would like to explain to me:

i) Isn't it a winner/loser pair for each game? How can a pair "outperform"
another? Nash equilibrium is about an overall better situation for both sides,
but if one is smarter enough than the other, it is better for this one not to
be on Nash equilibrium. So I don't see it as underperformed by a "Nash pair".

ii) Later in the article they explain that chimps have better short memory
than humans through an experiment where chimps correctly recall numbers that
appeared on a screen. My doubt: chimps can undersand the correct order of
numbers? In other words, chimps can read numbers _and_ understand their
order?? That is new to me.

Maybe I misread something...

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baha_man
i) "Isn't it a winner/loser pair for each game?"

Yes, if both players chose the same side, the 'matcher' wins. If they chose
different sides, the 'mismatcher' wins.

"How can a pair "outperform" another?"

A player is better at the game the closer to a game theory optimal strategy
they use. This would presumably be to chose left or right at random. The worst
strategy would be to always chose the same side, the matcher would then be
able to predict your next move with 100% accuracy.

Randomizing choices to be unpredictable is something humans aren't good at.
Poker players sometimes use tricks like checking the position of the second
hand of their watch to do this (e.g. if it's between 10 and 12, bet, if not,
check). The study suggests chimps may be better at it than us.

"Nash equilibrium is about an overall better situation for both sides..."

No, this is not correct.

ii) "...chimps can read numbers and understand their order?"

It sounds like it from this Wikipedia entry:

[http://en.wikipedia.org/wiki/Chimpanzee#Memory](http://en.wikipedia.org/wiki/Chimpanzee#Memory)

"A 30-year study at Kyoto University’s Primate Research Institute has shown
chimps are able to learn to recognize the numbers 1 through 9 and their
values... jumbled digits are flashed onto a computer screen for less than a
quarter of a second, after which the chimp, Ayumu, is able to correctly and
quickly point to the positions where they appeared in ascending order."

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soneca
If random is better so you might as well say that raindrops falling on a
monitor also outperform a human, as the issue seems to be that humans always
looks for a pattern, even when randomness is better. It is irrelevant that
they are chimps.

Would you care to explain what is the correct Nash equilibrium?

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baha_man
From Wikipedia
([http://en.wikipedia.org/wiki/Nash_equilibrium](http://en.wikipedia.org/wiki/Nash_equilibrium)):

"In game theory, the Nash equilibrium is a solution concept of a non-
cooperative game involving two or more players, in which each player is
assumed to know the equilibrium strategies of the other players, and no player
has anything to gain by changing only their own strategy."

So, it is not correct to say "Nash equilibrium is about an overall better
situation for both sides" \- one player wants to win at the expense of the
other.

Chosing sides at random is a game theory optimal strategy, that is, it is the
best strategy to use when your opponent always choses the best counter-
strategy. If the two players flip coins to chose their sides they will both
end up winning 50% of games in the long run. Likewise if they are able to
randomize their choices perfectly, they will both win 50% of games.

If your opponent plays in a sub-optimal manner (e.g. they chose the left side
more often than the right), then the best strategy to use is an _exploitative_
one (e.g. I see you chose left more than right so I always chose left),
however, in this case you gain by changing your strategy (so no Nash
equilibrium).

I can't see any way to 'beat' this simple game and win more than 50% of games
in the long run without using an exploitable strategy, so it seems that chimps
have somehow evolved to become better at playing this game in a game theory
optimal manner than us.

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aric
It's worth watching these short videos from years ago to get an idea, though
this is a different game. Chimps outperforming humans in memory games:

1\. "Man Vs Chimp - memory test"

[https://www.youtube.com/watch?v=OVlJv7ZkvGA](https://www.youtube.com/watch?v=OVlJv7ZkvGA)

2\. etc.

[https://www.google.com/search?q=chimp+memory&tbm=vid](https://www.google.com/search?q=chimp+memory&tbm=vid)

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pazimzadeh
Would it not have been more interesting if players were unknowingly set up
against the other species, for comparison?

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WalterBright
Since chimps can rip my arms off if they get mad at me, I always let them win.

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lotu
If you get a human mad at you they will try to wipe out your entire race so I
feel it is a bit of a toss up.

~~~
hnriot
not before destroying your habitat!

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frozenport
They are also better at climbing trees...

