On the other hands

IT SOUNDS like an easy question for any half-competent scientist to answer. Do dark-skinned footballers get given red cards more often than light-skinned ones? But, as Raphael Silberzahn of IESE, a Spanish business school, and Eric Uhlmann of INSEAD, an international one (he works in the branch in Singapore), illustrate in this week's Nature, it is not. The answer depends on whom you ask, and the methods they use. Dr Silberzahn and Dr Uhlmann sought their answers from 29 research teams. They gav...