The village that would not boil its water

Los Molinas was a village of about two hundred families on the coast of Peru, where most people worked as field hands and drew water from an irrigation ditch, a well and a stream, all of them contaminated. The public health service sent a worker, Nelida, to persuade the village's housewives to boil water before drinking it. She had help: a doctor who gave public talks, and fifteen households that already boiled. Over two years she visited every home in the village, and worked especially hard on twenty-one families. At the end, eleven of them boiled their water regularly.

The anthropologist Edward Wellin, who lived in the village during the campaign, explained why. The villagers sorted foods, liquids and remedies into hot and cold, a quality separate from temperature, and the sick had to avoid extremes of either. Raw water was very cold, so boiling it made it fit for a sick person to drink. Boiled water was medicine. A healthy housewife who began boiling would be announcing an illness, or behaving strangely. Nelida's explanation of germs did not replace that belief; it was heard through it.

Who adopted mattered as much as why most people did not. One of the adopters Rogers profiles was a woman the village called the sickly one, who boiled water for the old reasons. Another had come from the highlands, was treated as an outsider, and had little social standing to lose. The households whose example the village followed were not among the eleven, and Nelida, who spent her time with the people most willing to listen, came to be identified with the margins herself. Rogers draws the two lessons the whole book rests on: an innovation spreads according to how well it fits what people already believe, and according to who adopts it first and whether anyone else is watching them.

The campaign had everything a launch usually has: a better product, a clear explanation, expert endorsement, two years of effort and a few early users. It failed because the message landed on a belief it never addressed. Every market has a version of hot and cold, a way customers already explain the thing you want to change, and your product gets read through it whatever you meant to say. Before launching, find that frame out, from the people themselves rather than from your own team, and either fit the message to it or change it on purpose.

The second lesson is about who goes first. Early users are easy to find among people with little to lose, and they prove nothing to anyone else. The customers who move a market are the ones others watch, and they come later and need a different case. If your first adopters are all on the edge, you have a pilot, which is a different thing from a launch.

Diffusion of Innovations

Everett M. Rogers, 1962

The book that explains how new ideas spread, and why most do not, from the researcher who spent his career on the question. It opens with the Peruvian village, and the first chapter alone is worth the price.