People decide whether to share social information–and whether to share it accurately–on the basis of self-interest

Why do people spend so much time gossiping? Here, we tested two distinct hypotheses about how people might use reputational information to achieve social goals. Indirect Reciprocity theory entails the hypothesis that people share information about themselves and others accurately in order to reward cooperators and punish defectors. In contrast, Reputation-Based Partner Choice theory proposes that people share, withhold, and distort information about themselves and others in order to secure high-quality cooperation partners. We found that subjects were more likely to share information about others' (and their own) previous generosity if they themselves had been generous rather than greedy. Previously generous people were most likely to gossip—and previously greedy people were least likely —under conditions in which sharing and withholding gossip, respectively, were in their material interest. Likewise, previously generous people were most likely to share honest gossip—and previously greedy people were most likely to share dishonest gossip—when it was in their material interest. Finally, previously generous people were less likely than previously greedy people to share dishonest gossip that yielded a competitive advantage. Although these results fit more comfortably with Reputation-based Partner Choice theory than with Indirect Reciprocity theory as commonly understood, nearly 30 % of subjects shared information even when it did not pay to do so. This finding suggests that people's decisions about sharing reputational information are not driven exclusively by short-term material considerations, although we did not explore the self-interested desire to avoid the social cost of being caught lying.