WEDNESDAY, Jan. 23, 2002 (HealthDayNews) -- Scientists studying human interactions in a game setting have made a discovery that might help solve serious global issues such as climate change.
They have found a potential solution to the "public goods" dilemma, which describes the problem of trying to maintain a public resource that everyone is free to use -- or overuse. History has shown that, while most countries initially contribute to the resource, cooperation rapidly breaks down, and the resource becomes abused.
The latest study, which appears in tomorrow's issue of Nature, found that by combining the public goods game with a game that functions on the basis of "give and you shall receive," or indirect reciprocity, cooperation to maintain the public resource remains high.
Using 114 first-year university students, Manfred Milinski and his colleagues at the Max Planck Institute of Limnology in Germany formed 19 groups of six people, and ran a computerized experiment using social games. Milinski, a professor of evolutionary ecology, gave each player an account of 20 deutsche marks (DM) to add to or lose, based on their decisions in the game.
Each volunteer was assigned a randomly generated name, and played the game anonymously under that name. The players could see a public computer screen that displayed the rules of the game they would play.
In the public goods game, the players were asked simultaneously if they would like to donate DM 2.50 to a public pool, which is then doubled and equally distributed back to all of the players. After the distribution, each player's decision, contribution and gain is displayed next to their pseudonym on the public computer screen.
While the group would profit the most if everyone contributes DM 2.50, the first player who doesn't chip in profits the most personally. Once that happens, the cooperation breaks down within a few rounds.
In the indirect reciprocity game, one player would ask on the public computer screen whether another specific player would give him money. If the player agreed, DM 2.50 would be subtracted from his account and DM 4 would appear in the receiver's account. The potential donor's decision was displayed on the public screen, and over time each player builds up a reputation as being either generous or stingy.
A recent study had showed that in the public goods game, cooperation would continue at a high level -- roughly 90 percent -- if players were given the chance to punish non-cooperators.
But Milinski and his colleagues found they could achieve the same effect -- without punishment -- by alternating rounds of public goods and indirect reciprocity.
People who failed to contribute in the public goods rounds risked gaining a reputation for stinginess, and suffered in the following indirect reciprocity round. The solution was to contribute generously in the next public goods round.
"We did not expect such a strong effect," says Milinski. "We thought there might be some influence of this game on the result of the other game, but we did not at all expect that we would keep up cooperation at almost 90 percent."
Karl Sigmund, a University of Vienna professor of mathematics who co-authored a seminal study on indirect reciprocity, says the findings are fascinating. He says that since humans have evolved over millions of years from other social species, "we are extremely well-adapted to these public goods interactions."
"We probably all have a very good instinctive feeling for these interactions," he says. "The interesting thing now is that in addition to that, we can measure and we can analyze this in simpler situations."
But he stresses this field is still not fully understood, and it may be too early to apply these findings to some of the more practical problems facing society, such as international disputes over climate change.
Sigmund says he doubts that understanding these systems will change how humans behave in the real world, just as understanding the physics of tennis won't turn an amateur into Pete Sampras.
"In the real world, you find these punishment-and-reward systems everywhere, but you find so many other factors that it is difficult to disentangle [them]," he says.
Milinski says that while the findings may not provide concrete solutions to problems such as negotiating treaties on climate change, they would advise that countries try to have as many different types of interactions as possible.
"It needs another interaction among the same people in which reputation is of value," says Milinski. "If people know who left the workshop in disorder, so that people can decrease that person's reputation
then this person would suffer."
What To Do
You can find out about the theory behind the "tragedy of the commons" dilemma from the University of Michigan.
Learn more about Sigmund's work on indirect reciprocity.
