Those who are successful at creating social epidemics do not just do what they think is right. They deliberately test their intuitions.

But do you know what the experimentation statistics are for illegal drugs? In the 1996 Household Survey on Drug Abuse, 1.1 percent of those polled said that they had used heroin at least once. But only 18 percent of that 1.1 percent had used it in the past year, and only 9 percent had used it in the past month.

Perhaps the most sophisticated analysis of this process of translation comes from the study of rumors, which are—obviously—the most contagious of all social messages. In his book The Psychology of Rumor, the sociologist Gordon Allport writes of a rumor involving a Chinese teacher who was traveling through Maine on vacation in the summer of 1945, sh

In a social epidemic, Mavens are data banks. They provide the message. Connectors are social glue: they spread it. But there is also a select group of people—Salesmen—with the skills to persuade us when we are unconvinced of what we are hearing, and they are as critical to the tipping of word-of-mouth epidemics as the other two groups.

They aren’t separate worlds, though. The point about Connectors is that by having a foot in so many different worlds, they have the effect of bringing them all together.

To be a Maven is to be a teacher. But it is also, even more emphatically, to be a student. Mavens are really information brokers, sharing and trading what they know.

“If the goal of visionaries is to make a quantum leap forward, the goal of pragmatists is to make a percentage improvement—incremental, measurable, predictable progress,”

These three characteristics—one, contagiousness; two, the fact that little causes can have big effects; and three, that change happens not gradually but at one dramatic moment

“In other words, effects of rearing variation (e.g. parents’ lighting up or not, or having cigarettes in the home or not) were essentially nil by the time the children reached adulthood,” the psychologist David Rowe writes in his 1994 book summarizing research on the question, The Limits of Family Influence.