“Like everyone else, scientists have intuitions. Indeed, hunches and flashes of insight—the sense that something is true even if you can’t prove it—have been behind countless breakthroughs. The interplay between System 1 and System 2 can be subtle and creative. But scientists are trained to be cautious. They know that no matter how tempting it is to anoint a pet hypothesis as The Truth, alternative explanations must get a hearing. And they must seriously consider the possibility that their initial hunch is wrong. In fact, in science, the best evidence that a hypothesis is true is often an experiment designed to prove the hypothesis is false, but which fails to do so. Scientists must be able to answer the question “What would convince me I am wrong?” If they can’t, it’s a sign they have grown too attached to their beliefs.”