New neuroscience proves the clearer your position, the easier the decision. Here’s an experiment I love. Researchers recently showed people circles filled with hundreds of parallel lines. Each participant had to learn an invisible rule: Lines tilted one side of a particular angle belonged in Category A, while lines tilted the other way belonged in Category B. The dividing angle could be something totally random, like 73 degrees. Nobody was told what it was. Through trial and error, most...