What if the solutions to many of the world's, and America's, challenges of health, education, and productivity already exist and are waiting to be multiplied? That's the premise of a new approach to innovation described by Rebecca Tuhus-Dubrow in "The Power of Positive Deviants." 

Instead of imposing solutions from without, the method [of Positive Deviance] identifies outliers in a community who, despite having no special advantages, are doing exceptionally well. By respecting local ingenuity, proponents say, the approach galvanizes community members and is often more effective and sustainable than imported blueprints.

There are hidden innovators everywhere, from rice farmers in Vietnam to patient transporters in New England hospitals. Sometimes neighbors and coworkers copy them spontaneously, but often custom and top-down management limit the spread of their ideas. Agencies and philanthropies can promote nutrition and health by helping lower the barriers and spread the word. 

The optimistic essay omits a sad fact of innovation--that some of the greatest outliers have lacked the personal and political skills to spread their ideas against entrenched opposition of their peers. Think of the hero and martyr of medical antisepsis, the Hungarian doctor Ignaz Semmelweis. 

In the countryside, positive deviance can encounter other kinds of obstacles, including dietary habits and cultivation systems. John Reader, in his recent book "Potato," points out that seventeenth-century German peasants desperate to preserve their food sources from marauding troops became the pioneers of planting the still-mistrusted New World tuber. Even so, eighteenth-century rulers like Frederick the Great had to threaten draconian punishments to encourage a partial shift from grain. French peasants resisted the potato at least until the food crises of the 1790s, though the royal enthusiasts Louis XVI (said to have worn a potato flower on his coat) and Marie Antoinette did their best until the end. The greatest ally of positive deviance is sometimes not enlightened encouragement but desperation.