The Power of Positive Deviance: How Unlikely Innovators Solve the World’s Toughest Problems

Richard Pascale, Jerry Sternin, & Monique Sternin

256 pages, Harvard Business Press, 2010

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In The Power of Positive Deviance, authors Richard Pascale, Jerry Sternin, and Monique Sternin take their readers on a fascinating tour to learn about “positive deviance”—an approach to solving social, and even some business, problems.

The approach, which the authors developed from work done by Tufts University nutrition professor Marian Zeitlin in the 1980s—has roughly three steps. First, engage the people needing change in the process; they must take part in discovering answers to their problems to adopt changes. Second, identify “positive deviants”—people who seem to have succeeded compared with others, despite having the same resources. Finally, work with communities to pinpoint what the positive deviants do differently, and figure out how the whole community can adopt these successful practices.

The authors’ tour starts in rural Vietnam, where they explore how households there might use existing resources to feed their children more nutritionally. Then it’s on to Egypt, where they look for ways to change opinions and practices on female circumcision. Back in Pittsburgh, they examine how doctors and nurses working in hospitals might wash their hands more often. And all the while you feel like you’re sitting at a dinner table as three engaging people recount their round-the-world adventure and quest to improve the quality of life around them. The authors describe their locations wonderfully and keep their prose crisp and to the point.

I’m always happy, too, when advocates for a particular policy are realistic about its limitations, and these authors put forward two clear limitations: Positive deviance works only to change existing behaviors—not to introduce new technologies; and specific lessons learned in one place sometimes don’t work elsewhere.

By the end of the book I felt hopeful of positive deviance’s future success and glad that the authors reached thousands of people during their journey, possibly starting them on a trajectory of success. And yet I was left hungry for more. I wanted to stay at that dinner table even though the stories were over, and say, “We can take this to the masses and get more facilitators doing this only when you’ve shown that positive deviance truly works.”

The evidence the authors put forward typically consists of “here is where folks in our study were before” and “here is where they are afterward” (sometimes referred to as before-and-after studies). Other things are happening at the same time that can cause trends to occur, and the people who participate in programs often tend to be different: They are likely striving to succeed and searching for ways out of their problem. In social science, we call this a selection bias, and we are certain that it wreaks havoc on knowing whether the positive deviance approach worked, or if the individuals who participated would have experienced better outcomes anyhow—because of either their environment or their spirit to succeed.

To illustrate this evaluation challenge, let’s go to the opening story on nutrition in Vietnam. Some parents, just as poor as everyone else, were feeding their kids crabs and shrimp that they collected daily from rice paddies and added to the soup. These kids were not malnourished. And so the authors identified them as the positive deviants, others adopted their practices, and then lots more children escaped malnourishment. But this was part of a larger program, run by the same organization, in which parents and caretakers were also given tofu and eggs to feed their children. So what caused the reduction in malnourishment—the little shrimp and crabs that positive deviance told them to feed their children, or the free handouts of tofu and eggs?

In another story, the authors used positive deviance to help identify why some salespeople at a pharmaceutical company sold a lot of one particular drug while others didn’t. The authors tell us that a sign of positive deviance’s success was that sales increased on average for everyone. But three tidbits give me pause. First, the drug was upgraded, so perhaps sales increased in response to the upgrade. Second, even in the later time period, the positive deviants were still deviating. Maybe positive deviants kept some ideas to themselves or discovered new ones, or the mimicry didn’t work: Sometimes an apprentice can mimic but still doesn’t get it quite right. Last, we learn that the pharmaceutical company did not continue with the positive deviance approach, despite the before-and-after increase in sales. I had to wonder: Would the pharmaceutical company have been more likely to adopt this if it were faced with evidence more akin to randomized trials—what companies usually use to determine if something works or not?

I also wanted answers about how to truly identify the behavior that causes the positive deviation. This identification may not be simple in many settings, and in the book, it felt as if community members were being asked to conduct complicated econometric, analytical, or theoretical exercises that would establish causal relationships between behaviors and outcomes.

And last but not least: What will positive deviance cost if implemented on a large scale, such as an entire region or a country? How many failed attempts occurred (e.g., when no positive deviant behavior was identified or adopted) for each of the success stories we heard about? I want answers not because I’m an accountant or an economist, but because I want to support the ideas that are the most effective per dollar donated or invested.

Ultimately, I’d recommend that proponents of positive deviance apply a bit of positive deviance to positive deviance itself—a meta-study, so to speak. Is positive deviance the approach that works best, compared with other approaches? Setting up randomized evaluations and comparing positive deviance with other methods (or nothing at all) would help us know if positive deviance is indeed a positive deviant. With clear, concrete evidence, people hoping to solve social problems could listen, learn, and adopt positive deviance themselves. In which case this book can serve as a great starter kit, whetting their appetites and generating the enthusiasm for further exploration.

Dean Karlan is a professor of economics at Yale University and president and founder of Innovations for Poverty Action. His research focuses on design and evaluation of programs around the world, on topics including microcredit, microsavings, voting, charitable fundraising, health behavior modifi cation, behavioral economics, community-driven development, and microinsurance.