Humans prefer cockiness to expertise

Peter Aldhous:

EVER wondered why the pundits who failed to predict the current economic crisis are still being paid for their opinions? It’s a consequence of the way human psychology works in a free market, according to a study of how people’s self-confidence affects the way others respond to their advice.
The research, by Don Moore of Carnegie Mellon University in Pittsburgh, Pennsylvania, shows that we prefer advice from a confident source, even to the point that we are willing to forgive a poor track record. Moore argues that in competitive situations, this can drive those offering advice to increasingly exaggerate how sure they are. And it spells bad news for scientists who try to be honest about gaps in their knowledge.
In Moore’s experiment, volunteers were given cash for correctly guessing the weight of people from their photographs. In each of the eight rounds of the study, the guessers bought advice from one of four other volunteers. The guessers could see in advance how confident each of these advisers was (see table), but not which weights they had opted for.