Saturday, April 18, 2009
Cooperation Beats Selfishness, at Least in Theory
In these dark days, science brings a glimmer of hope: even in a world that rewards selfishness, cooperation can emerge and ultimately prevail.
That world happens to be a computer simulation, but I'll take good news anywhere I can get it.
"We report the sudden outbreak of predominant cooperation in a noisy world dominated by selfishness and defection," write Swiss Federal Institute of Technology sociologists Dirk Helbing and Wenjian Yu in a paper published Monday in the Proceedings of the National Academy of Sciences.
Helbing specializes in complex simulations of crowd behavior, from fans in a soccer stadium to traffic jams. But like other crowd modelers, he's been stuck on a basic conundrum, known best from the Prisoner's Dilemma: if cooperative behavior potentially provides the highest rewards, but selfishness is the safest and most sensible course of action, how can cooperation emerge?
The key, suggests Helbing's simulation, is mobility and imitation. When individuals are free to choose their associates and smart enough to imitate their success, cooperation emerges, then flourishes — and it doesn't take much to start the process. At each iteration in the simulation, just one in 20 units had a chance of abandoning selfishness, and the choice was usually punished.
"After a very long time, there will be two or three or four individuals in the same neighborhood who just happen to cooperate, just by chance," said Helbing. "It's a happy coincidence — and once there's a sufficiently large cluster, cooperators do quite well. Defectors start to copy the behavior of cooperative clusters. And cooperation can persist and spread."
In many ways, the Prisoner's Dilemma simulation is for game theorists what fruit flies are to biologists: a simple system in which basic principles can be uncovered, examined and hopefully extrapolated to people. It's just a model; a bit of mobility and imitation won't magically fix humanity's problems. But they might be important.
"The sheer fact of moving from one place to another might have been an important precondition for the emergence and spreading of cooperation" in human cultural evolution, said Helbing.
There might also be a lesson in Helbing's shifting red-and-blue dots for the cities of the future, where migratory populations often are often stuck in immigrant neighborhoods and denied social opportunities.
"We face a huge amount of migration worldwide, and it's expected on an even larger scale in decades to come," he said. "According to experience, it takes one or two generations for newcomers and their families to integrate fully. That's a very long time. We have to have more efficient integration."
Citation: "The outbreak of cooperation among success-driven individuals under noisy conditions." By Dirk Helbing and Wenjian Yu. Proceedings of the National Academy of Sciences, Vol. 106, No. 8, Feb. 23, 2009.