Experts talk a lot of junk. The more famous they are, the more hooey they talk. The media tarts in this study by Phillip E Tetlock made worse predictions of future events than his control group of dart-throwing chimps. The famous study hasn’t done much to humble commentators. They come to prominence by talking sense on issues they understand. As their profile grows, they accept invitations to comment on a wider range of topics outside their fields. Before they know it, they are making asinine statements on Q&A.