The more people rely on their intuitions, the more cooperative they become

It's an age old question: Why do we do good? What makes people sometimes willing to put "We" ahead of "Me?" Perhaps our first impulse is to be selfish, and cooperation is all about reining in greed. Or maybe cooperation happens spontaneously, and too much thinking gets in the way.

Harvard scientists are getting closer to an answer, showing that people's first response is to cooperate and that stopping to think encourages selfishness.

David Rand, a Post-Doctoral Fellow in Psychology, Joshua Greene, the John and Ruth Hazel Associate Professor of the Social Sciences in the Department of Psychology, and Martin Nowak, Professor of Mathematics and of Biology, and Director of the Program for Evolutionary Dynamics, have published their findings in the September 20 issue of Nature. They recruited thousands of participants to play a "public goods game" in which it's "Me" vs. "Us." Subjects were put into small groups and faced with a choice: Keep the money you've been given, or contribute it into a common pool that grows and benefits the whole group. Hold onto the money and you come out ahead, but the group does best when everyone contributes.

The researchers wanted to know whether people's first impulse is cooperative or selfish. To find out, they started by looking at how quickly different people made their choices, and found that faster deciders were more likely to contribute to the common good.