Cheaters (and now diehard punishers) never prosper

As AP reports it “Screaming sports coaches and cutthroat tycoons have it wrong: Nice guys do finish first, a new study suggests.”

The current issue of Nature summarizes the results of a Harvard study with 100 college students from Boston playing prisoner’s dilemma game.
The AP reported: “Common game theory has held that punishment makes two equals cooperate. But when people compete in repeated games, punishment fails to deliver, said study author Martin Nowak. He is director of the evolutionary dynamics lab at Harvard where the study was conducted….”On the individual level, we find that those who use punishments are the losers,” Nowak said his experiments found.” And those who punished the most, did the worst.

Nowak and all found that none of the top 5 finishers used costly punishment and the use of costly punishment didn’t help groups overall. Effective players used a *tit for tat* strategy, much as Axelrod found earlier. Punishment may force others to do what you want, but researchers found that the situation could rapidly deteriorate.

See article on their story “It Pays to be Nice.”

And a related article in Nature called *Punisher Pays* by M. Milinski and B. Rockenbach. Abstract: The tendency of humans to punish perceived free-loaders, even at a cost to themselves, is an evolutionary puzzle: punishers perish, and those who benefit the most are those who have never punished at all.
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Journal Nature

Play prisoner’s dilemma (without Nowak’s costly punishment) against a computer.

Evolving to cooperate

Martin Nowak, at Harvard, has conducted some interesting research modeling cooperation.  He shows how irregular verbs die out since the social process of people using verbs more often increases their regularization.  His work describes how bicyclists trade positions in the lead (much like geese flying in “V formation”) to draft for each other save on their collective use of energy.  He describes his field of study as evolutionary dynamics.

With Harvard Divinity School professor Sarah Coakley he’s working to develop a mathematics and evolution of cooperation.

Nowak points out that: “The most competitive scenario of natural selection, where everybody competes with everybody else, can actually lead to features like generosity and forgiveness….That I find great.”

Originally modeling cooperation in the prisoner’s dilemma, he developed a theory that also applied to professional cyclists. “Last year, cyclist George Hincapie came to a professional road race championship with only one teammate to help him set the pace and battle the wind; and both Levi Leipheimer and David Zabriskie came alone. Even though they were some of the best cyclists in the world, it would be nearly impossible for any one of them to win facing teams with many more riders. So all four worked together trading the lead, so three could conserve energy while one battled the wind. Hincapie and Leipheimer finished one-two.”

“Cooperation means someone pays a cost and someone else gets a benefit,” Nowak said. “I study what makes cooperation a winning strategy. I analyze it using a metaphor that comes from biological evolution natural selection and mutation,” and these basic principles, he said, can be described by exact mathematical equations.

“Nowak defines evolution more broadly than simply the changing of genes, which is what brought him into the study of language. The Nature paper, researched by some of his students, concludes that most English verbs behave in an extremely regular way, evolving, for instance, to end in “ed,” such as “helped,” “laughed,” “reached,” “walked,” and “worked.” Certain irregular verbs, including “be” and “think,” haven’t made that transformation, even though they are 38,800 and 14,400 years old respectively, because they are used so frequently. “The study reveals a simple mathematical law of language evolution,” said Nowak. “If a verb is used 100 times less frequently, it regularizes 10 times faster.’ ”

“Human societies are made up of individuals that cooperate. Whenever evolution is doing something amazingly new, cooperation is involved,”  Nowak said.

“The most successful cooperators, his equations show, choose generosity over greed, forgiveness over retaliation, but there’s a message, he believes, that goes beyond his mathematical models.”

See Cooperation Counts for Math Professor (Boston Globe, 10/15/07, by Heather Wax)