Social Network and Cooperation with Strangers

Cooperation with strangers in one-shot encounters poses a puzzle that is difficult to reconcile with perspectives of rational self-interest and natural selection. The quality of prior “social experience” offers a possible explanation, but the underlying mechanism remains unclear. We hypothesize that people in more closed social networks are less likely to cooperate with a stranger. Further, success reinforces the network predisposition. Regardless of the reason for success, people who have enjoyed success with the network they have feel that their network is a good one. Our second hypothesis is that successful people with a closed social network are reinforced in their social behavior, and are therefore especially unlikely to cooperate with an outsider. Both hypotheses are strongly supported by network and behavioral data on a stratified area probability sample of 500 CEOs in China’s Yangtze River Delta region. Learning seems the most likely causal mechanism driving our differences in cooperation with str...