Abstract
We tend to think of knowledge in positive terms -- and of experts as people who know what to do. But a 'negative' way to seem competent is, simply, never to make mistakes. How much of what we learn to do -- and learn to think -- is of this other variety? It is hard to tell, experimentally, because knowledge about what not to do never appears in behavior. And it is also difficult to assess, psychologically, because many of the judgments that we traditionally regard as positive -- such as beauty, humor, pleasure, and decisiveness -- may actually reflect the workings of unconscious double negatives