New research shows people quit smoking not as individuals but in complex social clusters, each strongly influencing the others. Friends, spouses, relatives, and other social contacts all exercise an overwhelming sway over individual decisions to quit. The study covered 58,000 people from 1971 to 2003, the New York Times reports, when smoking declined precipitously across the US.
“We tend to think of individuals as atomized units, and we think of policies as good or bad for individuals,” said the principal research scientist at Yahoo Research in New York. “This reminds us that we are all connected to each other, and when we do something to one person, there are spillover effects.”