Transcript Introduction to Complex Systems: How to think like nature Organizations: when groups are better than individuals Russ Abbott Sr.

Introduction to Complex Systems:
How to think like nature
Organizations: when groups are better than
individuals
Russ Abbott
Sr. Engr. Spec.
310-336-1398
Innovation required
individual autonomy.
What do groups add?
[email protected]
 1998-2007. The Aerospace Corporation. All Rights Reserved.
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“Self-organizing” groups
• Craig Reynolds wrote the first flocking
program two decades ago:
http://www.red3d.com/cwr/boids.
• Here’s a good current interactive version:
http://www.lalena.com/AI/Flock/
– Separation: Steer to avoid crowding birds of the
same color.
– Alignment: Steer towards the average heading of
birds of the same color.
– Cohesion: Steer to move toward the average
position of birds of the same color.
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“Self-organizing” groups
• The bird, termite, and ant models illustrate emergence (and
multi-scalarity). (See video Debora Gordon on ant colonies.)
• In both cases, individual, local, low-level rules enabled “the
group” to achieve “emergent” higher level results.
– The birds flocked.
– The wood chips were gathered into a single pile.
– The food was brought to the nest.
• Exploratory behavior extends the perceptual reach of any
individual.
Emergence is successful group design.
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Breeding groups
Traditional evolutionary theory says there is no such
thing as group selection, only individual selection.
Bill Muir (Purdue) demonstrated that was wrong.
http://www.ansc.purdue.edu/faculty/muir_r.htm
• Chickens are fiercely competitive for food and water.
• Commercial birds are beak-trimmed to reduce
cannibalization.
• Breeding individual chickens to yield more eggs
compounds the problem. Chickens that produce
more eggs are more competitive.
• Instead Muir bred chickens by groups.
Wikipedia commons
• At the end of the experiment Muir's birds' mortality rate was 1/20 that of
the control group. His chickens produced three percent more eggs per
chicken and (because of the reduced mortality) 45% more eggs per
group.
• Group (and more generally multi-level) selection is now accepted as valid.
Groups are entities. You and I are both entities and cell colonies.4
Why groups? Two steps.
• Perhaps groups formed initially because they increased survival
value. A team will generally beat an individual of approximately the
same skill level.
– This is not so much emergence as power in numbers.
• But then groups found that coordination,
specialization, and coordinated specialization
enabled emergence.
– Consider any multi-cellular organism, or any
organism with multiple organs, or any society
with any sort of specialization, or any social
grouping with coordinated and/or specialized
roles.
– These groups exemplify real emergence.
Entirely new capabilities appear.
•
•
Wind instruments can play melodies.
Piano and guitar can play chords as well.
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David Sloan Wilson on groups
Moral systems are interlocking sets of values, practices,
institutions, and evolved psychological mechanisms that
work together to suppress or regulate selfishness and
make social life possible. —Jonathan Haidt
• What holds for chickens holds for other groups as well: teams, military units,
corporations, religious communities, cultures, tribes, countries.
• Successful groups are those that minimize within-group conflict and organize
to succeed at between-group conflict. We evolved to be pro-social within groups but
xenophobic between groups. – Michael Shermer
• Groups with mechanisms for working together can often accomplish far more
(emergence) than the sum of the individuals working separately.
– Corporations, military organizations; reproduction; mitochondria and “us.”
• But if a group good is also an individual good (e.g., money, security), the
group must have mechanisms to limit cheating (free-ridership).
• Group traits (although they are carried as rules by individuals) evolve
because they benefit the group. (E.g., insect behavior.)
• These traits may be transmitted genetically (by DNA). They may also be
transmitted culturally (by training/parenting/indoctrination/mentoring/…).
– Human groups are much more complex because it’s not all built-in.
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Experimental “games”
C
C
D
3/3
0/5
• Prisoner’s Dilemma.
D
5/0
1/1
– One shot. Defect is the only rational strategy.
– Iterated.
• Tit-for-tat: Cooperate initially and then copy the other guy.
• Pavlov: repeat on success; change on failure. (More robust.)
A far-from-equilibrium system. New energy is supplied “for free.”
• Ultimatum Game. Proposer must offer to divide $100—e.g., from TAI.
Responder either accepts the proposed division or rejects it—in which
case neither gets anything.
– Only rational strategy: proposer offers as little as possible; responder
always accepts.
– Real experiments (world-wide). Responder rejects unless offer ~1/3.
– Some societies are different, e.g., where giving a gift means power.
– What would you offer/accept? Try it. (Played anonymously. Write offer.)
• Try it table against table. Each table prepares an offer.
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Homo economicus vs. strong reciprocity
Homo economicus: individual selection
• Agents care only about the outcome of an economic interaction
and not about the process through which this outcome is
attained (e.g., bargaining, coercion, chance, voluntary transfer).
• Agents care only about what they personally gain and lose
through an interaction and not what other agents gain or lose (or
the nature of these other agents’ intentions).
• Except for sacrifice on behalf of kin, what appears to be altruism
(personal sacrifice on behalf of others) is really just long-run
material self-interest.
• Ethics, morality, human conduct, and the human psyche are to
be understood only if societies are seen as collections of
individuals seeking their own self-interest.
Moral Sentiments and Material Interests: The Foundations of Cooperation in Economic Life
Herbert Gintis, Samuel Bowles, Robert T. Boyd, and Ernst Fehr (eds), MIT Press, 2005.
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Homo economicus vs. strong reciprocity
Strong reciprocity: group selection
• A predisposition to cooperate with others, and to punish (at personal cost, if necessary)
those who violate the norms of cooperation
– even when it is implausible to expect that these costs will be recovered at a later date.
• Strong reciprocators are both
conditional cooperators
They behave altruistically as long as others are doing so as well.
and
altruistic punishers
They apply sanctions to those who behave unfairly even at a cost to themselves.
Socialization: norm internalization.
There's no such thing in biology, economics, political science, or anthropology.
Humans can want things even when they are costly to ourselves because we
were socialized to want them
to be fair, to share, to help your group, to be patriotic, to be honest, to be trustworthy,
to be cheerful.
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Wise crowds: more than the sum of their parts
Traditional wise crowds
• Teams
• Juries
• Democratic voting
Web wise crowd platforms
• Wikis
• Mailing lists
• Chat rooms
• Prediction markets
•
•
•
•
Condorcet Jury Theorem (18th century) example
Five people (a small crowd).
Each person has a 75% chance of being right.
Probability that the majority will be right: ~90%
With 10 people: ~98%. Simple if you think about it.
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Wise crowd criteria
James Surowiecki, The Wisdom of Crowds
Diverse: different skills and information brought to the table.
• Decentralized and with independent participants:
Participant
autonomy.
• No one at the top dictates the crowd's answer.
•
•
Each person is free to speak his/her own mind and make own decision.
Distillation mechanism: to extract the essence of the crowd's wisdom.
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Example from The Difference
• Which person from the following list was not a member of the Monkees (a 1960s
pop band)?
Diverse groups of problem solvers outperformed the groups of the
(A) Peter Tork
best individuals at solving problems. The diverse groups got stuck
(B) Davy Jones
(C) Roger Noll
less often than the smart individuals, who tended to think similarly.
(D) Michael Nesmith
• Imagine a crowd of 100 people with knowledge distributed as follows:
• 7 know all 3 of the Monkees
• 10 know 2 of the Monkees
• 15 know 1 of the Monkees
• 68 have no clue
In other words, less than 10 percent of the crowd knows the answer, and over twothirds are culturally deprived of any Monkees knowledge. We assume individuals
without the answer vote randomly. The Condorcet Jury Theorem, then, doesn’t
apply because only a small minority knows the answer. Still, the crowd will have no
problem getting the right answer.
• The 7 who know all the Monkees vote for X;
• 5 of the 10 who know 2 of the Monkees will vote for X;
• 5 of the 15 who know 1 of the Monkees will vote for X; and
• 17 of the 68 clueless will vote for Noll.
So X will garner 34 votes, versus 22 votes for each of the other choices.
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A wise crowd as assistant and companion
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Distillation mechanism: prediction markets
Statement issued by 25 world-famous academics. May 2007.
Including: Kenneth Arrow, Daniel Kahneman, Thomas Schelling,
Robert Shiller, Cass Sunstein.
Abstract: Prediction markets are markets for contracts that yield
payments based on the outcome of an uncertain future event, such as a
presidential election. Using these markets as forecasting tools could
substantially improve decision making in the private and public sectors.
We argue that U.S. regulators should lower
barriers to the creation and design of prediction
markets by creating a safe harbor for certain
types of small stakes markets. We believe our
proposed change has the potential to stimulate
innovation in the design and use of prediction
markets throughout the economy, and in the
process to provide information that will benefit
the private sector and government alike.
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Often Beats Alternatives
• Vs. Public Opinion
– I.E.M. beat presidential election polls 451/596 (Berg et al ‘01)
– Re NFL, beat ave., rank 7 vs. 39 of 1947 (Pennock et al ’04)
• Vs. Public Experts
– Racetrack odds beat weighed track experts (Figlewski ‘79)
• If anything, track odds weigh experts too much!
– OJ futures improve weather forecast (Roll ‘84)
– Stocks beat Challenger panel (Maloney & Mulherin ‘03)
– Gas demand markets beat experts (Spencer ‘04)
– Econ stat markets beat experts 2/3 (Wolfers & Zitzewitz ‘04)
from Robin Hanson
• Vs. Private Experts
– HP market beat official forecast 6/8 (Plott ‘00)
– Eli Lily markets beat official 6/9 (Servan-Schreiber ’05)
– Microsoft project markets beat managers (Proebsting ’05)
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Market mechanisms
• Intrade uses a continual double auction—bid and asked prices. (Like stocks.)
– Requires high liquidity or a market maker.
– Aggregates information in price; can buy or sell any time.
• Pari-Mutual. Losing bets distributed to winning betters. (Like horse racing).
– Requires neither liquidity nor a market maker.
– Aggregates information as odds. Can’t trade. Prices don’t vary. No profit in
being right early. Best strategy is to wait until the last minute. But that reduces
the amount of information supplied to the pool.
– kahst.
• Market Scoring Rules (Robin Hanson) and Dynamic Pari-Mutuel Market (David M.
Pennock & Mike Dooley).
– Combines pari-mutuel with continual double auction.
– Benefit for being right early.
– MSR: Inkling, Qmarkets; DPM: Yahoo! Tech Buzz Game.
• List of markets: MidasOracle.org.
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Split off from
TradeSports
Prediction markets
Contracts: Intrade (Ireland-based): real money or play money.
But, there is evidence that prediction markets are not efficient.
Panos Ipeirotis
Slate’s
Election
Market
Page
Other Intrade contracts: Current Events > Google Lunar X Prize
Land a privately funded robotic rover on the Moon that is capable of completing several mission objectives,
including roaming the lunar surface for at least 500 meters and sending video, images and data back to the Earth.
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Concerns and Myths
from Robin Hanson
• Self-defeating prophecies
• Decision selection bias
• Price manipulation
• Rich more “votes”
• Inform “enemies”
• Share less info
• Combinatorics
• Risk distortion
• Moral hazard
• Alarm public
• Embezzle
• Bubbles
• Crowds don’t always beat experts.
• People will not work for trinkets.
• High accuracy is not assured.
• Bozos
• Lies
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Other distillation mechanisms:
making the crowd’s “wisdom” “actionable”
• Elections, polls, etc. Traditional. Many possible
processes, e.g., transferrable ballots, etc.
– Expression of preferences.
– Many online options (and more options).
• Collaboration: wikis and other collaboration tools
(shared spaces), mailing lists, chat rooms, etc.
– Explicit: Generation of new “work products.”
• Here’s a (long!) list of collaborative work environments.
– Implicit: Google’s page rank, “reputations” (e.g., eBay),
“recommendation engines” (e.g., Amazon)
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Backups
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When cells reach the point where they divide
constantly, they are cancer cells. Instead multicellular organisms use a seemingly inefficient
process to replace lost cells.
An organ such as the skin calls upon skin-specific
stem cells to produce intermediate cells that in
turn produce skin cells. Although great at their
job, the new skin cells are evolutionary dead ends.
They cannot reproduce.
Losing the ability to reproduce was part of the
evolutionary path single-celled organisms had to
take to become multi-cellular.
What was in it for the single cells? They got to be
part of something more powerful. Something that
was hard to eat and good at eating other things.
Stem cells
instead of cancer
John W. Pepper, University of Arizona
Organisms are just a bunch of cells. If you
understand the conditions under which they
cooperate, you can understand the conditions
under which cooperation breaks down. Cancer is a
breakdown of cooperation.
If cells reproduce by simply
making carbon-copies of
themselves, their descendants
are more likely to accumulate
mutations. Suppressing
mutations that might fuel
uncontrolled growth of cells
would be particularly
important for larger organisms
that had long lives
Animal Cell Differentiation Patterns Suppress Somatic Evolution ,PLoS Computational Biology Vol. 3, No. 12, (12/2007)
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Group/system-level emergence
• Both the termite and ant models illustrate emergence (and multiscalarity). (See video Debora Gordon on ant colonies.)
• In both cases, individual, local, low-level rules and interactions
produce “emergent” higher level results.
– The wood chips were gathered into a single pile.
– The food was brought to the nest.
• Emergence in ant and termite colonies may seem different from
emergence in E. coli following a nutrient gradient because we see ant
and termite colonies as groups of agents and E. coli as a single entity.
• But emergence as a phenomenon is the same. In both cases we can
explain the design of the system, i.e., how the system works. In the
ant/termite examples, the colony is the system. In the case of E. coli,
the organism is the system.
In Evolution for Everyone, David Sloan Wilson
argues that all biological and social elements are
best understood as both groups and entities.
You and I are each (a) entities and (b) cell colonies.
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The Public Goods Game
• Contributions to a common pot grow—via emergence. The result is
divided among everyone, even free-riders.
• Free riders do better than cooperators/contributors.
• But then cooperation (and public goods) will vanish.
• Punishment is important in sustaining cooperation.
• But how can punishment emerge if it is costly?
Categories of players
•
•
•
•
Loners do not participate; they neither contribute nor benefit.
Defectors do not contribute but benefit.
Cooperators contribute and benefit but do not punish.
Punishers are contributors who also (pay to) punish defectors and simple
cooperators—to prevent simple cooperators from free-riding on punishers.
Which category dominates depends on modeling assumptions.
Games
of Life
Hannelore Brandt, Christoph Hauert, and Karl Sigmund, “Punishing and abstaining
for public goods,” PNAS, Jan 10, 2006. http://www.pnas.org/cgi/reprint/103/2/495
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We’re smart because we are “programmable,”
i.e., able to learn—both information and norms
As humans we’re successful because we’re smart.
We’re smart because we operate in complex groups.
We can operate in complex groups because we have
strong reciprocity.
We both share and are willing to punish non-sharers.
Next slide
Take bees.
You always think of the hive as the big social
collective. Not true. Workers often try to lay eggs, even
though only the queen is supposed to lay eggs. If
workers lay eggs, other workers run around, eat the
eggs, and then punish the workers that laid the eggs.
Wherever you find cooperation, you’ll also find
punishment. Think of your own body.
Each cell has its own self-interest to multiply. Why
don’t they go berserk (cancer)? How do you get cells to
cooperate? You punish cells that don’t cooperate.
Herbert Gintis
Clearly fundamental. How
are we autonomous?
Socialization: norm internalization.
There's no such thing in biology,
economics, political science, or
anthropology.
Humans can want things even
when they are costly to ourselves
because we were socialized to
want them
to be fair, to share, to help your
group, to be patriotic, to be honest,
to be trustworthy, to be cheerful.
What does it mean to say that we
can learn?
The word may sound cold and
robotic, but it means that we are
“programmable,” i.e., capable of
internalizing new skills and ideas.
Socialization is a form of learning.
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