Defying expectations

This exercise is a part of Educator Guide: Look to the Outliers / View Guide

Directions for teachers: Ask students to read the online Science News article Why do some people succeed when others fail? Outliers provide clues,” which describes how research into communities that defy expectations can reveal ways to help others, and answer the following questions. A version of the article, “Look to the outliers,” appears in the February 26, 2022 issue of Science News.

1. Why are Somali villages with sustainable grazing considered outliers? Based on your answer, how would you define an outlier?

The few Somali villages with sustainable grazing are considered outliers because they have been able to maintain healthy rangeland despite years of severe drought, unlike the majority of villages. An outlier is a single data point, individual or community that exists far from the average or outside a cluster of data points.

2. What is “business as usual” for outliers in data analysis? What problem does this pose for social science researchers?     

Removing outliers from data is considered business as usual. But that practice contributes to an overreliance on averages, which could obscure vital information and lead to overlooking certain groups of people.

3. How and why are some social scientists using outliers in their research? What is this approach called?

Some scientists are searching datasets for outliers that hold useful information about why some people or communities succeed when others fail. Understanding what sets the successful outliers, or positive deviants, apart could then be used to help other people or communities succeed. This approach is called “positive deviance.”

Rebels among us

4. How did researchers use positive deviance to help malnourished children in Vietnam in the 1990s? What was the long-term result of the researchers’ intervention?


Researchers found that some families kept their children well-nourished by feeding them what was considered taboo or unhealthy food (tiny shrimp and crabs) and by feeding their kids three to four meals per day instead of the typical two meals. These families were considered positive deviants or outliers. The team then established cooking sessions taught by village women where families of malnourished children could see for themselves that the taboo foods made the children healthier, not sicker. A year after the intervention, more than a thousand children were no longer malnourished.

5. Name one drawback of the approach.

It would have been unethical to expose families that were breaking social norms, so finding a way to get more families to feed their children “taboo” foods was difficult.

Going bigger

6. Compare development researcher Basma Albanna’s positive deviance approach with the approach used by researchers in Vietnam. What makes the approaches different?

The methods of collecting data to find the positive deviants were different between the approaches. The positive deviance approach used in Vietnam required researchers to gather data from individual people to find positive outliers. Albanna’s approach relies mostly on existing population-level datasets.

7. What is “big data” and what benefits does it offer to researchers using positive deviance?

Big data refers to datasets that are exceedingly large and diverse. The benefits of big data in positive deviance research can include less labor-intensive data collection since the datasets already exist, reduced privacy concerns since data is collected at the village or neighborhood level instead of at the individual level, and an increased likelihood of finding positive outliers since the datasets are so large.

8. Summarize how Albanna and colleagues used positive deviance to study Somali villages in Africa. Make sure your summary identifies what the positive outliers were and what they revealed about how villages might be able to survive periods of severe drought.

Albanna’s team looked at rainfall, land cover and vegetation data for more than 300 villages over a five-year period and found 13 villages that were able to maintain healthy vegetation despite a severe drought. An analysis of satellite images as well as interviews with villagers revealed certain practices that were unique to the positive outliers. Examples include shrub barriers to mitigate erosion, carved basins to retain water and policies to prevent people from privatizing land.  

Targeted interventions

9. What are nudges? Who do nudge interventions typically focus on?

Nudges are policies or incentives aimed at guiding people toward making better decisions. Nudge interventions typically focus on people who are in the middle class and above.

10. How might a focus on outliers and positive deviance influence the effect of nudge interventions?

Focusing on outliers may make nudge interventions more powerful and effective for people who fall outside the average and who could benefit from nudges the most.

11. What is the next step for Albanna’s team in the research of Somali villages?

The team is now investigating how the practices used by the successful villages can be used to develop nudge interventions.

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