What do economists mean when they refer to you as a “rational agent”? Why might a psychologist label your idea a “creative insight”? And how can different scientists disagree on the results of experiments that assess our risk for disease? The problem-solving methods that these experts use affect our daily lives, determining whether we are guilty or innocent, where we should invest our money, and whether the medicine we are taking is effective. But their decisions often seem counterintuitive to you and me – and sometimes they just seem wrong.