Continuing this level of surprise, the researchers think that cooperators, although in the minority, constituted the most powerful force within the group. They established the level of contribution, and the reciprocators, not willing to be left behind, coughed up an equal amount, maintaining the status quo and enlarging the pot that was to be shared by all.
Kuzban and Houser, who published their findings in a recent online edition of the Proceedings of the National Academy of Sciences, think there's something here that could be useful beyond the college lab. How a team leader communicates with all the members of the team can be a major factor in the success of the team.
Since reciprocators respond to cooperators, they need to know quite clearly that George contributed a bundle or they won't give much themselves. Of course, the free riders won't give a rip.
So let's hear it for the cooperators.
"These cooperators are doing an interesting amount of work because when they are placed in groups with reciprocators they are essentially enlisting large amounts of cooperation from the reciprocal types. So these guys are a key element. They draw out the reciprocators," Kurzban says.
"They plant seeds of cooperation."
Of course, we're not all college students, and that can be a very different animal. "It's what we call a convenience sample," as Kurzban puts it.
But he believes these findings will be replicated in other experiments involving different age groups and different cultures, including Japan.
Other researchers have completed similar studies, and "they find substantial stability among the different age groups," Kurzban says. "That gives me some optimism."
In the end, he hopes to answer the "big question." It will likely show that cooperation evolved in humans because those cultures that didn't cooperate, regardless of how large or how small they were, didn't survive.
In human evolution, survival of the fittest may simply mean we learn to work together or we die.
Lee Dye's column appears weekly on ABCNEWS.com. A former science writer for the Los Angeles Times, he now lives in Juneau, Alaska.