An expert on folk legends, Jan Brunvand, says that legends “acquire a good deal of their credibility and effect from their localized details.”

A person’s knowledge of details is often a good proxy for her expertise. Think of how a history buff can quickly establish her credibility by telling an interesting Civil War anecdote. But concrete details don’t just lend credibility to the authorities who provide them; they lend credibility to the idea itself. The Civil War anecdote, with lots of interesting details, is credible in anyone’s telling. By making a claim tangible and concrete, details make it seem more real, more believable.

Observing their own behavior, the coaches learn the lesson—how they found it easier to criticize than to support, to think of ten clever insults rather than a single consolation. Thompson found a way to transform his point into a testable credential, something the coaches could experience for themselves.

In this chapter we’ve seen that the most obvious sources of credibility—external validation and statistics— aren’t always the best. A few vivid details might be more persuasive than a barrage of statistics. An anti-authority might work better than an authority. A single story that passes the Sinatra Test might overcome a mountain of skepticism. It’s inspirational to know that a medical genius like Marshall had to climb over the same hurdles with his idea as we’ll have to climb with ours—and to see that he eventually prevailed, to the benefit of us all.

SUB-CAPABILITY NO.3: CREDIBILITY EQUITY

Sherman and Franklin made a huge impact late in life partly by drawing upon storehouses of credibility they’d built over decades. It wasn’t just Franklin’s words at the end of the Constitutional Convention that held sway, but also that these words came from Franklin. It wasn’t just that Sherman articulated a strong argument to preserve the actual text of the Constitution and use the amendment mechanism to include the Bill of Rights, but also that the argument came from Sherman.

The person closest to the problem often has the most accurate information about it. What they tend to lack is a broader perspective. The person working on the line at McDonald’s knows how to fix a recurring problem at their restaurant better than a person merely analyzing some data. What they don’t know is how it fits into the bigger picture. They don’t know whether the problem exists everywhere, or whether the solution wold cause more harm than good if implemented globally, or how to roll the idea out to everyone.