2. 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
3. The name given to that one dramatic moment in an epidemic when everything can change all at once is the Tipping Point.
4. And when an epidemic tips, when it is jolted out of equilibrium, it tips because something has happened, some change has occurred in one (or two or three) of those areas. These three agents of change I call the Law of the Few, the Stickiness Factor, and the Power of Context.
5. When it comes to epidemics, though, this disproportionality becomes even more extreme: a tiny percentage of people do the majority of the work.
6. In all of the city of Colorado Springs— a town of well in excess of 100,000 people— the epidemic of gonorrhea tipped because of the activities of 168 people living in four small neighborhoods and basically frequenting the same six bars. Who were those 168 people? They aren’t like you or me. They are people who go out every night, people who have vastly more sexual partners than the norm, people whose lives and behavior are well outside of the ordinary.
7. This idea of the importance of stickiness in tipping has enormous implications for the way we regard social epidemics as well. We tend to spend a lot of time thinking about how to make messages more contagious— how to reach as many people as possible with our products or ideas. But the hard part of communication is often figuring out how to make sure a message doesn’t go in one ear and out the other. Stickiness means that a message makes an impact. You can’t get it out of your head. It sticks in your memory.
8. The Stickiness Factor says that there are specific ways of making a contagious message memorable; there are relatively simple changes in the presentation and structuring of information that can make a big difference in how much of an impact it makes.
9. The Power of Context says that human beings are a lot more sensitive to their environment than they may seem.
10. The answer is that the success of any kind of social epidemic is heavily dependent on the involvement of people with a particular and rare set of social gifts: Connectors, Mavens, and Salesmen.
11. Most of us don’t have particularly broad and diverse groups of friends. In one well- known study, a group of psychologists asked people living in the Dyckman public housing project in northern Manhattan to name their closest friend in the project; 88 percent of the friends lived in the same building, and half lived on the same floor. In general, people chose friends of similar age and race.
12. But if the friend lived down the hall, then age and race became a lot less important. Proximity overpowered similarity.
13. We’re friends with the people we do things with, as much as we are with the people we resemble. We don’t seek out friends, in other words. We associate with the people who occupy the same small, physical spaces that we do.
14. The answer is that in the six degrees of separation, not all degrees are equal. When Milgram analyzed his experiment, for example, he found that many of the chains from Omaha to Sharon followed the same asymmetrical pattern. Twenty- four letters reached the stockbroker at his home in Sharon, and of those, sixteen were given to him by the same person, a clothing merchant Milgram calls Mr. Jacobs.
15. The balance of letters came to the stockbroker at his office, and of those the majority came through two other men, whom Milgram calls Mr. Brown and Mr. Jones. In all, half of the responses that came back to the stockbroker were delivered to him by these same three people.
16. Six degrees of separation doesn’t mean that everyone is linked to everyone else in just six steps. It means that a very small number of people are linked to everyone else in a few steps, and the rest of us are linked to the world through those special few.
17. These people who link us up with the world, who bridge Omaha and Sharon, who introduce us to our social circles— these people on whom we rely more heavily than we realize— are Connectors, people with a special gift for bringing the world together.
18. He found that 56 percent of those he talked to found their job through a personal connection. Another 18.8 percent used formal means— advertisements, headhunters— and roughly 20 percent applied directly. This much is not surprising; the best way to get in the door is through a personal contact. But, curiously, Granovetter found that of those personal connections, the majority were “weak ties.” Of those who used a contact to find a job, only 16.7 percent saw that contact “often”— as they would if the contact were a good friend— and 55.6 percent saw their contact only “occasionally.” Twenty- eight percent saw the contact “rarely.” People weren’t getting their jobs through their friends. They were getting them through their acquaintances.
19. Word- of- mouth epidemics are the work of Connectors.
20. Paul Revere was a Connector. But he was also— and this is the second of the three kinds of people who control word- of- mouth epidemics— a Maven. The word Maven comes from the Yiddish, and it means one who accumulates knowledge.
21. The critical thing about Mavens, though, is that they aren’t passive collectors of information. It isn’t just that they are obsessed with how to get the best deal on a can of coffee. What sets them apart is that once they figure out how to get that deal, they want to tell you about it too.
22. Mavens have the knowledge and the social skills to start word- of- mouth epidemics. What sets Mavens apart, though, is not so much what they know but how they pass it along. The fact that Mavens want to help, for no other reason than because they like to help
23. A Connector might tell ten friends where to stay in Los Angeles, and half of them might take his advice. A Maven might tell five people where to stay in Los Angeles but make the case for the hotel so emphatically that all of them would take his advice. These are different personalities at work, acting for different reasons. But they both have the power to spark word- of- mouth epidemics.
24. 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. Who are these Salesmen? And what makes them so good at what they do?
25. If we think about emotion this way— as outside- in, not inside- out— it is possible to understand how some people can have an enormous amount of influence over others. Some of us, after all, are very good at expressing emotions and feelings, which means that we are far more emotionally contagious than the rest of us. Psychologists call these people “senders.” Senders have special personalities.
26. They are also physiologically different. Scientists who have studied faces, for example, report that there are huge differences among people in the location of facial muscles, in their form, and also— surprisingly— even in their prevalence. “It is a situation not unlike in medicine,” says Cacioppo. “There are carriers, people who are very expressive, and there are people who are especially susceptible. It’s not that emotional contagion is a disease. But the mechanism is the same.”
27. Only the charismatic person could infect the other people in the room with his or her emotions.
28. The Law of the Few says that there are exceptional people out there who are capable of starting epidemics. All you have to do is find them.
29. The lesson of stickiness is the same. There is a simple way to package information that, under the right circumstances, can make it irresistible. All you have to do is find it.
30. Wilson and Kelling argued that crime is the inevitable result of disorder. If a window is broken and left unrepaired, people walking by will conclude that no one cares and no one is in charge. Soon, more windows will be broken, and the sense of anarchy will spread from the building to the street on which it faces, sending a signal that anything goes. In a city, relatively minor problems like graffiti, public disorder, and aggressive panhandling, they write, are all the equivalent of broken windows, invitations to more serious crimes: Muggers and robbers, whether opportunistic or professional, believe they reduce their chances of being caught or even identified if they operate on streets where potential victims are already intimidated by prevailing conditions. If the neighborhood cannot keep a bothersome panhandler from annoying passersby, the thief may reason, it is even less likely to call the police to identify a potential mugger or to interfere if the mugging actually takes place.
31. This is an epidemic theory of crime. It says that crime is contagious— just as a fashion trend is contagious— that it can start with a broken window and spread to an entire community.
32. Broken Windows theory and the Power of Context are one and the same. They are both based on the premise that an epidemic can be reversed, can be tipped, by tinkering with the smallest details of the immediate environment.
33. Psychologists call this tendency the Fundamental Attribution Error (FAE), which is a fancy way of saying that when it comes to interpreting other people’s behavior, human beings invariably make the mistake of overestimating the importance of fundamental character traits and underestimating the importance of the situation and context.
34. There is something in all of us that makes us instinctively want to explain the world around us in terms of people’s essential attributes: he’s a better basketball player, that person is smarter than I am.
35. Judith Harris has convincingly argued that peer influence and community influence are more important than family influence in determining how children turn out. Studies of juvenile delinquency and high school drop- out rates, for example, demonstrate that a child is better off in a good neighborhood and a troubled family than he or she is in a troubled neighborhood and a good family.
36. Wesley realized that if you wanted to bring about a fundamental change in people’s belief and behavior, a change that would persist and serve as an example to others, you needed to create a community around them, where those new beliefs could be practiced and expressed and nurtured.
37. Dunbar has actually developed an equation, which works for most primates, in which he plugs in what he calls the neocortex ratio of a particular species— the size of the neocortex relative to the size of the brain— and the equation spits out the expected maximum group size of the animal. If you plug in the neocortex ratio for Homo sapiens, you get a group estimate of 147.8— or roughly 150. “The figure of 150 seems to represent the maximum number of individuals with whom we can have a genuinely social relationship, the kind of relationship that goes with knowing who they are and how they relate to us.
38. Dunbar has combed through the anthropological literature and found that the number 150 pops up again and again. For example, he looks at 21 different hunter- gatherer societies for which we have solid historical evidence, from the Walbiri of Australia to the Tauade of New Guinea to the Ammassalik of Greenland to the Ona of Tierra del Fuego and found that the average number of people in their villages was 148.4.
39. Over the years military planners have arrived at a rule of thumb which dictates that functional fighting units cannot be substantially larger than 200 men,” Dunbar writes. “This, I suspect, is not simply a matter of how the generals in the rear exercise control and coordination, because companies have remained obdurately stuck at this size despite all the advances in communications technology since the first world war.
40. Then there is the example of the religious group known as the Hutterites, who for hundreds of years have lived in self- sufficient agricultural colonies in Europe and, since the early twentieth century, in North America. The Hutterites (who came out of the same tradition as the Amish and the Mennonites) have a strict policy that every time colony approaches 150, they split it in two and start a new one. “Keeping things under 150 just seems to be the best and most efficient way to manage a group of people,” Bill Gross, one of the leaders of a Hutterite colony outside Spokane told me. “When things get larger than that, people become strangers to one another.”
41. The Rule of 150 suggests that the size of a group is another one of those subtle contextual factors that can make a big difference.
42. Heavy smokers have been shown to have a much greater sex drive than nonsmokers. They are more sexually precocious; they have a greater “need” for sex, and greater attraction to the opposite sex.
43. At age nineteen, for example, 15 percent of nonsmoking white women attending college have had sex. The same number for white female college students who do smoke is 55 percent.
44. Contagiousness is in larger part a function of the messenger. Stickiness is primarily a property of the message.
45. In a series of large and well-designed studies of twins — particularly twins separated at birth and reared apart — geneticists have shown that most of the character traits that make us who we are — friendliness, extroversion, nervousness, openness, and so on — are about half determined by our genes and half determined by our environment, and the assumption has always been that this environment that makes such a big difference in our lives is the environment of the home. The problem is, however, that whenever psychologists have set out to look for this nurture effect, they can’t find it.
46. On things like measures of intellectual ability and certain aspects of personality, the biological children are fairly similar to their parents. For the adopted kids, however, the results are downright strange. Their scores have nothing whatsoever in common with their adoptive parents: these children are no more similar in their personality or intellectual skills to the people who raised them, fed them, clothed them, read to them, taught them, and loved them for sixteen years than they are to any two adults taken at random off the street.
47. Two years later, Columbia University psychologist Alexander Glassman discovered that 60 percent of the heavy smokers he was studying as part of an entirely different research project had a history of major depression. About 80 percent of alcoholics smoke. Close to 90 percent of schizophrenics smoke.