The Tipping Point Read online

  Social epidemics work in exactly the same way. They are also driven by the efforts of a handful of exceptional people. In this case, it’s not sexual appetites that set them apart. It’s things like how sociable they are, or how energetic or knowledgeable or influential among their peers. In the case of Hush Puppies, the great mystery is how those shoes went from something worn by a few fashion forward downtown Manhattan hipsters to being sold in malls across the country. What was the connection between the East Village and Middle America? The Law of the Few says the answer is that one of these exceptional people found out about the trend, and through social connections and energy and enthusiasm and personality spread the word about Hush Puppies just as people like Gaetan Dugas and Nushawn Williams were able to spread HIV.

  2.

  In Baltimore, when the city’s public clinics suffered cutbacks, the nature of the syphilis affecting the city’s poor neighborhoods changed. It used to be an acute infection, something that most people could get treated fairly quickly before they had a chance to infect many others. But with the cutbacks, syphilis increasingly became a chronic disease, and the disease’s carriers had three or four or five times longer to pass on their infection. Epidemics tip because of the extraordinary efforts of a few select carriers. But they also sometimes tip when something happens to transform the epidemic agent itself.

  This is a well known principle in virology. The strains of flu that circulate at the beginning of each winter’s flu epidemic are quite different from the strains of flu that circulate at the end. The most famous flu epidemic of all—the pandemic of 1918—was first spotted in the spring of that year and was, relatively speaking, quite tame. But over the summer the virus underwent some strange transformation and over the next six months ended up killing between 20 and 40 million people worldwide. Nothing had changed in the way in which the virus was being spread. But the virus had suddenly become much more deadly.

  The Dutch AIDS researcher Jaap Goudsmit argues that this same kind of dramatic transformation happened with HIV. Goudsmit’s work focuses on what is known as Pneumocystis carinii pneumonia, or PCP. All of us carry the bacterium in our bodies, probably since birth or immediately thereafter. In most of us it is harmless. Our immune systems keep it in check easily. But if something, such as HIV, wipes out our immune system, it becomes so uncontrollable that it can cause a deadly form of pneumonia. PCP is so common among AIDS patients, in fact, that it has come to be seen as an almost certain indication of the presence of the virus. What Goudsmit did was go back in the medical literature and look for cases of PCP, and what he found is quite chilling. Just after World War II, beginning in the Baltic port city of Danzig and spreading through central Europe, there was an epidemic of PCP that claimed the lives of thousands of small children.

  Goudsmit has analyzed one of the towns hit hardest by the PCP epidemic, the mining town of Heerlen in the Dutch province of Limburg. Heerlen had a training hospital for midwives called the Kweekschool voor Vroedvrouwen, a single unit of which—the so called Swedish barrack—was used in the 1950s as a special ward for underweight or premature infants. Between June 1955 and July 1958, 81 infants in the Swedish barrack came down with PCP and 24 died. Goudsmit thinks that this was an early HIV epidemic, and that somehow the virus got into the hospital, and was spread from child to child by the then, apparently common, practice of using the same needles over and over again for blood transfusions or injections of antibiotics. He writes:

  Most likely at least one adult—probably a coal miner from Poland, Czechoslovakia, or Italy—brought the virus to Limburg. This one adult could have died from AIDS with little notice....He could have transmitted the virus to his wife and offspring. His infected wife (or girlfriend) could have given birth in a Swedish barrack to a child who was HIV infected but seemingly healthy. Unsterilized needles and syringes could have spread the virus from child to child.

  The truly strange thing about this story, of course, is that not all of the children died. Only a third did. The others did what today would seem almost impossible. They defeated HIV, purged it from their bodies, and went on to live healthy lives. In other words, the strains of HIV that were circulating back in the 1950s were a lot different from the strains of HIV that circulate today. They were every bit as contagious. But they were weak enough that most people—even small children—were able to fight them off and survive them. The HIV epidemic tipped in the early 1980s, in short, not just because of the enormous changes in sexual behavior in the gay communities that made it possible for the virus to spread rapidly. It also tipped because HIV itself changed. For one reason or another, the virus became a lot deadlier. Once it infected you, you stayed infected. It stuck.

  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. When Winston filter tip cigarettes were introduced in the spring of 1954, for example, the company came up with the slogan “Winston tastes good like a cigarette should.” At the time, the ungrammatical and somehow provocative use of “like” instead of “as” created a minor sensation. It was the kind of phrase that people talked about, like the famous Wendy’s tag line from 1984 “Where’s the beef?” In his history of the cigarette industry, Richard Kluger writes that the marketers at R. J. Reynolds, which sells Winston, were “delighted with the attention” and “made the offending slogan the lyric of a bouncy little jingle on television and radio, and wryly defended their syntax as a colloquialism rather than bad grammar.” Within months of its introduction, on the strength of that catchy phrase, Winston tipped, racing past Parliament, Kent, and L&M into second place, behind Viceroy, in the American cigarette market. Within a few years, it was the bestselling brand in the country. To this day, if you say to most Americans “Winston tastes good,” they can finish the phrase, “like a cigarette should.” That’s a classically sticky advertising line, and stickiness is a critical component in tipping. Unless you remember what I tell you, why would you ever change your behavior or buy my product or go to see my movie?

  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.

  3.

  Every time someone in Baltimore comes to a public clinic for treatment of syphilis or gonorrhea, John Zenilman plugs his or her address into his computer, so that the case shows up as a little black star on a map of the city. It’s rather like a medical version of the maps police departments put up on their walls, with pins marking where crimes have occurred. On Zenilman’s map the neighborhoods of East and West Baltimore, on either side of the downtown core, tend to be thick with black stars. From those two spots, the cases radiate outward along the two central roadways that happen to cut through both neighborhoods. In the summer, when the incidence of sexually transmitted disease is highest, the clusters of black stars on the roads leading out of East and West Baltimore become thick with cases. The disease is on the move. But in the winter months, the map changes. When the weather turns cold, and the people of East and West Baltimore are much more likely to stay at home, away from the bars and clubs and street corners where sexual transactions are made, the stars in each neighborhood fade away.

  The seasonal effect on the number of cases is so strong that it is not hard to imagine that a long, hard winter in Baltimore could be enough to slow or lessen substantially—at least for the season—the growth of the syphilis epidemic.

  Epidemics, Zenilman’s map demonstrates, are strongly influenced by their situation—by the circumstances and cond
itions and particulars of the environments in which they operate. This much is obvious. What is interesting, though, is how far this principle can be extended. It isn’t just prosaic factors like the weather that influence behavior. Even the smallest and subtlest and most unexpected of factors can affect the way we act. One of the most infamous incidents in New York City history, for example, was the 1964 stabbing death of a young Queens woman by the name of Kitty Genovese. Genovese was chased by her assailant and attacked three times on the street, over the course of half an hour, as thirty eight of her neighbors watched from their windows. During that time, however, none of the thirty eight witnesses called the police. The case provoked rounds of self recrimination. It became symbolic of the cold and dehumanizing effects of urban life. Abe Rosenthal, who would later become editor of the New York Times, wrote in a book about the case:

  Nobody can say why the thirty eight did not lift the phone while Miss Genovese was being attacked, since they cannot say themselves. It can be assumed, however, that their apathy was indeed one of the big city variety. It is almost a matter of psychological survival, if one is surrounded and pressed by millions of people, to prevent them from constantly impinging on you, and the only way to do this is to ignore them as often as possible. Indifference to one’s neighbor and his troubles is a conditioned reflex in life in New York as it is in other big cities.

  This is the kind of environmental explanation that makes intuitive sense to us. The anonymity and alienation of big city life makes people hard and unfeeling. The truth about Genovese, however, turns out to be a little more complicated—and more interesting. Two New York City psychologists—Bibb Latane of Columbia University and John Darley of New York University—subsequently conducted a series of studies to try to understand what they dubbed the “bystander problem.” They staged emergencies of one kind or another in different situations in order to see who would come and help. What they found, surprisingly, was that the one factor above all else that predicted helping behavior was how many witnesses there were to the event.

  In one experiment, for example, Latane and Darley had a student alone in a room stage an epileptic fit. When there was just one person next door, listening, that person rushed to the student’s aid 85 percent of the time. But when subjects thought that there were four others also overhearing the seizure, they came to the student’s aid only 31 percent of the time. In another experiment, people who saw smoke seeping out from under a doorway would report it 75 percent of the time when they were on their own, but the incident would be reported only 38 percent of the time when they were in a group. When people are in a group, in other words, responsibility for acting is diffused. They assume that someone else will make the call, or they assume that because no one else is acting, the apparent problem—the seizure like sounds from the other room, the smoke from the door—isn’t really a problem. In the case of Kitty Genovese, then, social psychologists like Latane and Darley argue, the lesson is not that no one called despite the fact that thirty eight people heard her scream; it’s that no one called because thirty eight people heard her scream. Ironically, had she been attacked on a lonely street with just one witness, she might have lived.

  The key to getting people to change their behavior, in other words, to care about their neighbor in distress, sometimes lies with the smallest details of their immediate situation. The Power of Context says that human beings are a lot more sensitive to their environment than they may seem.

  4.

  The three rules of the Tipping Point—the Law of the Few, the Stickiness Factor, the Power of Context—offer a way of making sense of epidemics. They provide us with direction for how to go about reaching a Tipping Point. The balance of this book will take these ideas and apply them to other puzzling situations and epidemics from the world around us. How do these three rules help us understand teenage smoking, for example, or the phenomenon of word of mouth, or crime, or the rise of a bestseller? The answers may surprise you.

  TWO

  The Law of the Few

  CONNECTORS, MAVENS,

  AND SALESMEN

  On the afternoon of April 18, 1775, a young boy who worked at a livery stable in Boston overheard one British army officer say to another something about “hell to pay tomorrow.” The stable boy ran with the news to Boston’s North End, to the home of a silversmith named Paul Revere. Revere listened gravely; this was not the first rumor to come his way that day. Earlier, he had been told of an unusual number of British officers gathered on Boston’s Long Wharf, talking in low tones. British crewmen had been spotted scurrying about in the boats tethered beneath the HMS Somerset and the HMS Boyne in Boston Harbor. Several other sailors were seen on shore that morning, running what appeared to be last minute errands. As the afternoon wore on, Revere and his close friend Joseph Warren became more and more convinced that the British were about to make the major move that had long been rumored—to march to the town of Lexington, northwest of Boston, to arrest the colonial leaders John Hancock and Samuel Adams, and then on to the town of Concord to seize the stores of guns and ammunition that some of the local colonial militia had stored there.

  What happened next has become part of historical legend, a tale told to every American schoolchild. At ten o’clock that night, Warren and Revere met. They decided they had to warn the communities surrounding Boston that the British were on their way, so that local militia could be roused to meet them. Revere was spirited across Boston Harbor to the ferry landing at Charlestown. He jumped on a horse and began his “midnight ride” to Lexington. In two hours, he covered thirteen miles. In every town he passed through along the way—Charlestown, Medford, North Cambridge, Menotomy—he knocked on doors and spread the word, telling local colonial leaders of the oncoming British, and telling them to spread the word to others. Church bells started ringing. Drums started beating. The news spread like a virus as those informed by Paul Revere sent out riders of their own, until alarms were going off throughout the entire region. The word was in Lincoln, Massachusetts, by one a.m., in Sudbury by three, in Andover, forty miles northwest of Boston, by five a.m., and by nine in the morning had reached as far west as Ashby, near Worcester. When the British finally began their march toward Lexington on the morning of the nineteenth, their foray into the countryside was met—to their utter astonishment—with organized and fierce resistance. In Concord that day, the British were confronted and soundly beaten by the colonial militia, and from that exchange came the war known as the American Revolution.

  Paul Revere’s ride is perhaps the most famous historical example of a word of mouth epidemic. A piece of extraordinary news traveled a long distance in a very short time, mobilizing an entire region to arms. Not all word of mouth epidemics are this sensational, of course. But it is safe to say that word of mouth is—even in this age of mass communications and multimillion dollar advertising campaigns—still the most important form of human communication. Think, for a moment, about the last expensive restaurant you went to, the last expensive piece of clothing you bought, and the last movie you saw. In how many of those cases was your decision about where to spend your money heavily influenced by the recommendation of a friend? There are plenty of advertising executives who think that precisely because of the sheer ubiquity of marketing efforts these days, word of mouth appeals have become the only kind of persuasion that most of us respond to anymore.

  But for all that, word of mouth remains very mysterious. People pass on all kinds of information to each other all the time. But it’s only in the rare instance that such an exchange ignites a word of mouth epidemic. There is a small restaurant in my neighborhood that I love and that I’ve been telling my friends about for six months. But it’s still half empty. My endorsement clearly isn’t enough to start a word of mouth epidemic, yet there are restaurants that to my mind aren’t any better than the one in my neighborhood that open and within a matter of weeks are turning customers away. Why is it that some ideas and trends and messages “tip” and others don’t?


  In the case of Paul Revere’s ride, the answer to this seems easy. Revere was carrying a sensational piece of news: the British were coming. But if you look closely at the events of that evening, that explanation doesn’t solve the riddle either. At the same time that Revere began his ride north and west of Boston, a fellow revolutionary—a tanner by the name of William Dawes—set out on the same urgent errand, working his way to Lexington via the towns west of Boston. He was carrying the identical message, through just as many towns over just as many miles as Paul Revere. But Dawes’s ride didn’t set the countryside afire. The local militia leaders weren’t alerted. In fact, so few men from one of the main towns he rode through—Waltham—fought the following day that some subsequent historians concluded that it must have been a strongly pro British community. It wasn’t. The people of Waltham just didn’t find out the British were coming until it was too late. If it were only the news itself that mattered in a word of mouth epidemic, Dawes would now be as famous as Paul Revere. He isn’t. So why did Revere succeed where Dawes failed?

  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. Revere’s news tipped and Dawes’s didn’t because of the differences between the two men. This is the Law of the Few, which I briefly outlined in the previous chapter. But there I only gave examples of the kinds of people—highly promiscuous, sexually predatory—who are critical to epidemics of sexually transmitted disease. This chapter is about the people critical to social epidemics and what makes someone like Paul Revere different from someone like William Dawes. These kinds of people are all around us. Yet we often fail to give them proper credit for the role they play in our lives. I call them Connectors, Mavens, and Salesmen.