The 'contagion' of social networks

The old folk concept that our personal health behaviors rub off on those around us has received a staggering amount of scientific support of late. Over the last few years, study after study has shown that weight gain, drug and alcohol use, even loneliness and depression aren't islands unto themselves but are powerfully contagious — capable of spreading within our social networks just as germs scatter after a sneeze.

By Eric Jaffe, Special to the Los Angeles Times

September 13, 2010