How you feel about your abilities — your academic “self-concept” — in the context of your classroom shapes your willingness to tackle challenges and … - Malcolm Gladwell

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.

There’s no possibility of being pessimistic when people are dependent on you for their only optimism.

When Larry Sherman designed the Kansas City gun experiment, he was well aware of this problem. “You wouldn’t tell doctors to go out and start cutting people up to see if they’ve got bad gallbladders,” Sherman says. “You need to do lots of diagnosis first before you do any kind of dangerous procedure. And stop-and-search is a dangerous procedure. It can generate hostility to the police.” To Sherman, medicine’s Hippocratic oath — “First, do no harm” — applies equally to law enforcement. “I’ve just bought myself a marble bust of Hippocrates to try to emphasize every day when I look at it that we’ve got to minimize the harm of policing,” he went on. “We have to appreciate that everything police do, in some ways, intrudes on somebody’s liberty. And so it’s not just about putting the police in the hot spots. It’s also about having a sweet spot of just enough intrusion on liberty and not an inch — not an iota — more.