By using the tools of evolutionary theory and new approaches to mathematical modeling, researchers are drawing a clearer picture of how and why rumors spread. As they do, they are finding that far from being merely idle or malicious gossip, rumor is deeply entwined with our history as a species. It serves some basic social purposes and provides a valuable window on not just what people talk to each other about, but why.
Our behavior, McAndrew suggests, evolved in an environment in which information about others was crucially important. Back when humans lived in small groups, he theorizes, information about those higher than us on the totem pole - especially information about their weaknesses - would have been hugely valuable, and the only source we had for such information was other people. (McAndrew's work, much of which focuses on our obsession with celebrity culture, suggests our brains aren't terribly adept at distinguishing people who are "actually" important from people who simply receive a lot of attention.)