Under the right circumstances even greedy people will tend to cooperate. So finds SFI External Professor Dirk Helbing, a sociologist at the Swiss Federal Institute of Technology Zurich, and colleague Carlos Roca in a PNAS study in which they modeled how social cohesion emerges in a greedy group.
“We were interested in the conditions for the evolution of cooperation, when individuals repeat behaviors that pay off, but change their behavior or positions when they are not satisfied,” says Dirk.
In their model society, each person has up to eight neighbors. Everyone can choose to participate in a round of the game by contributing one unit of goods. Pool the goods, add a modestly amplifying synergy factor, then split the results evenly among all the neighbors. After each round, every person can choose to stay or move to a new neighborhood. Repeat.
In this setup, cooperating gives you more than what you started with, but being a deadbeat neighbor gives you something for nothing.
Participants could only look at their own past experience, not that of anyone else in the network. This simple structure eliminates punishment, forecasting, speculation, strategic moves to better neighborhoods, or reputation effects – effects typical of more complicated public goods games.
Starting simulations with slightly, moderately, and downright greedy people, the authors found that all networks iterated toward a tendency to cooperate, if individual greediness was allowed to evolve.
However, when people extrapolate future gains from an increase in past performance, their rise in expectations of greater personal returns (in short, increased greediness) can break down social cohesion, Dirk says.
Next, the researchers are planning experiments with actual human participants to see how well their model reflects the real world.