AUTHOR: BRANDON KEIM.
In a game where selfishness made more sense than cooperation, acts of giving were “tripled over the course of the experiment by other subjects who are directly or indirectly influenced to contribute more,” wrote political scientist James Fowler of the University of California, San Diego, and medical sociologist Nicholas Christakis of Harvard University.
Their findings, published March 8 in the Proceedings of the National Academy of Sciences, are the latest in a series of studies the pair have conducted on the spread of behaviors through social networks.
In other papers, they’ve described the spread of obesity, loneliness, happiness and smoking. But there was no way to know whether those apparent behavioral contagions were actually just correlations. People who are overweight, for example, might simply tend to befriend other overweight people, or live in an area where high-fat, low-nutrient diets are the norm.
The latest research was designed to identify cause-and-effect links. In it, Fowler and Christakis analyze the results of a so-called public-goods game, in which people were divided into groups of four, given 20 credits each, and asked to secretly decide what to keep for themselves and what to contribute to a common fund. That fund would be multiplied by two-fifths, then divided equally among the group. The best payoff would come if everyone gave all their money — but without knowing what others were doing, it always made sense to keep one’s money and skim from the generosity of others.