In a piece at the New York Magazine site, Matthew Hutson reviews evidence that overconfidence increases the confidence that others place in you. He cites a Berkeley study from 2012 that showed “that overconfidence increases one’s status. Subjects who overestimated their abilities at group tasks were more respected and influential in the group. It turns out, we tend to (over)use confidence as a useful proxy for competence - if you speak firmly, it sounds like you know what you’re talking about. People who showed more confidence, regardless of their actual ability, were judged to be more capable and accorded more regard by their peers.”
A more recent paper confirms and extend those findings. Researchers “showed subjects videos of actors playing subjects from a previous experiment. In the clips, the actors displayed either a medium or high amount of confidence during a group discussion, and subjects rated those displaying greater confidence as having more status (respect and influence) in the group. Then they were told the targets’ purported scores on a related task - they were in either the 47th or 91st percentile - and asked to rate them again. Even after learning the scores, subjects saw average performers as having higher status when they had lots of confidence than when their confidence matched their abilities.”
They discovered that “greater confidence leads to greater peer-rated social skill and greater peer-rated task ability, regardless of actual ability. The researchers suspect that confidence increases leadership-like behavior, such as talkativeness and active engagement, and also reduces anxiety, which allows for more fluid interaction, and that these behaviors may make one seem more socially skilled.”
In a pinch, it seems, overconfidence makes a fair substitute for competence.