Psychology Persuasion May 2nd 2002 From The Economist print edition Scientists are uncovering ways of making messages more persuasive. Politicians and salesmen use such tricks already. Who can afford not to read on? AKG YOUR correspondent was not sure whether to write this piece. But Eric Knowles, a professor of social psychology at the University of Arkansas, was very convincing. He said that he had experimental evidence to support a new approach to persuasion—one that works on removing people's inhibitions, or lowering their resistance. Dr Knowles is so compelling that he has managed to persuade America's National Science Foundation...