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July 24 - August 2, 2025
That’s the revenge of the Tipping Point: The very same tools we use to build a better world can also be used against us.
Social epidemics are propelled by the efforts of an exceptional few—people who play outsize social roles—and
He was once asked: “Why do you rob banks?” And he replied: “Because that’s where the money is.” Later he would deny having said that, but it didn’t matter. To this day his quip is known as “Sutton’s Law,” and it is used to instruct medical students on the importance of considering the likeliest diagnosis first.
Wennberg called what he had discovered “small-area variation,”
How your doctor treats you, in many cases, has less to do with where your doctor was trained, or how well he or she did in medical school, or what kind of personality your doctor has, than with where your doctor lives.
Wennberg and other researchers have found that small-area variation does not result from what patients want their doctors to do. It stems from what doctors want to do to their patients.
What he found instead were medical clusters, where the doctors in one hospital district took on a common identity, as if they had all been infected by the same contagious idea.
This is the first lesson of social epidemics. When we look at a contagious event, we assume that there is something fundamentally wild and unruly about the path it takes.
Whatever contagious belief unites the people in those instances has the discipline to stop at the borders of their community. There must be a set of rules, buried somewhere below the surface.
Communities have their own stories, and those stories are contagious. Actually, the word story isn’t quite right. A better word is overstory. An overstory is the upper layer of foliage in a forest, and the size and density and height of the overstory affect the behavior and development of every species far below on the forest floor. I think that small-area variation—such as what distinguishes Waldorf schools from other schools and what sets Boulder apart from Buffalo—is more like an overstory than a story. It’s not something explicit that’s drilled into every inhabitant. The overstory is made
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The overstory is specific. It is tied to a place. It is powerful. It shapes behavior. And it does not emerge out of nowhere. It happens for a reason.
If epidemics are influenced by the overstories created by the inhabitants of a community, then in what sense are communities responsible for the fevers and contagions that plague them?
The word used by biologists to describe an environment where individual differences have been sanded down and every organism follows the same path of development is monoculture. Monocultures are rare; the default state for most natural systems is diversity. A monoculture typically emerges only when something happens, deliberate or otherwise, to upset the natural order—for instance, when a group of affluent parents comes together to create a community that perfectly reflects their commitment to achievement and excellence.
Epidemics love monocultures.
This is what rebellion looks like in a monoculture: a deviation from the general path so slight that you would need an MRI to detect it. That lack of “crowd diversity” is what allowed Poplar Grove to score so highly in the state high-school rankings. It’s also what reassured parents. Your child might be an outsider, but at least they will be a high-achieving outsider.2 But what you give up in a world of uniformity is resilience.
The panther was saved. Where once the Florida-panther population had numbered in the dozens, now it numbers more than one hundred. But in order to be saved, it had to become something else—a hybrid of Texas and Florida. The best solution to a monoculture epidemic is to break up the monoculture.
Epidemics love monocultures. But so do we. Sometimes, in fact, we go out of our way to create them—even though in doing so we put our own children at risk.
The tipping point was a threshold: the moment when something that had seemed immovable—that had been one way for generations—transformed overnight into something else. Tipping points can be reached inadvertently. We can happen upon them by accident. Epidemics reach tipping points through their own relentless, contagious energy.
But in the next few chapters I want to explore the ways in which tipping points can be deliberately engineered.
Kanter became convinced that there is something uniquely toxic about groups with “skewed proportions,” featuring lots of one kind of person and very few of another kind.
By labeling her as exceptional, as some kind of singular genius, her colleagues didn’t have to revisit their ideas about what women—and, in particular, black women—were capable of. They could keep their belief systems intact.
When you are the only one of your kind, the world can’t see you as you.
I think we can go one step further. I think we can call the Magic Third a universal law. (Or at least something very close to universal.)
When a group of educational researchers led by Tara Yosso looked just at classrooms where the percentage of minority students exceeded 25 percent, they found the test-score gap completely vanished.4 The white students did as well as they always did. But now the black students had caught up.
The existence of tipping points creates an irresistible opportunity to engage in social engineering. It makes you want to tinker with the number of women on a corporate board or rearrange the minority students in an elementary classroom. But that doesn’t mean it’s easy.
somewhere? What’s so special about a really good tennis player? I’ve already given you the answer: What’s special about really good tennis players is that the only way to be a really good tennis player is to come from a wealthy family and live near a country club and have at least one parent with sufficient time on their hands to drive you all over the country for tournaments and handle the acquisition and management of the small army of coaches, trainers, physical therapists, and tutors you need to be successful.
athletic affirmative action admits privileged students with lower academic credentials. It is only the first kind of affirmative action, however, that universities were unwilling to defend. And only the first kind that was considered so controversial that it ended up before the Supreme Court.
We have looked, so far, at two elements of epidemics. The first is the overstory. The overstory casts a shadow over whatever is happening on the ground. The second element is group proportions. The mix of people in a group determines when and if that group tips.
One of the engines of the Poplar Grove epidemic was that the students who started the school’s suicide cluster had special status: They occupied a significant position in the school’s hierarchy. I talked about this idea in The Tipping Point. I called it the Law of the Few.
In Denver in 2006, Stedman discovered, 5 percent of the vehicles on the road produced 55 percent of the automobile pollution. That’s the Law of the Few: It’s a very large problem caused by a very small number of actors.
Somewhere around 10 percent of vehicles are, at any given time, responsible for over half the automobile-based air pollution. The distribution of polluting cars is—to borrow a phrase used in one study of drivers in Los Angeles—“extremely skewed.”
Moving from the position that a problem belongs to all of us to the position that a problem is being caused by a few of us is really difficult. And we are so intimidated by that difficulty, apparently, that we’d rather breathe dirty air.
It took a long time for this idea—that some people might excel at infecting others—to take hold in the scientific world.
The term superspreader didn’t come into regular use until the end of the 1970s, but even then the concept remained theoretical.
find? A full 86 percent of all of the COVID virus particles detected in their group of infected volunteers came from… two people. Airborne viruses do not operate according to the Law of the Few. They operate according to the Law of the Very, Very, Very Few.
In other words, a certain kind of individual—like that little girl in Rochester—produces lots of aerosol particles as part of their genetic makeup.
“If you stay well hydrated, your upper airways will capture pathogens all the time, and they move them—within twenty minutes or an hour—out into your gut and you swallow… and they’re eliminated that way,” Edwards said.
That’s why being dehydrated makes you more vulnerable to colds and the flu and COVID: When you exhale, those virus particles come back out—and now you are more likely not just to contract a virus but to spread it. The particles hit your dry airways and break up into a concentrated, foamy spray, like a big wave hitting a beach.
Why did it take until 1961—over fifteen years after the end of the Second World War—for there to be even a single monument to the Holocaust in the United States? And, more puzzlingly, Why did it take so long for the idea to spread across the country?
This kind of overstory is closer in meaning to what the Germans call the Zeitgeist, which translates literally as time-spirit. Zeitgeist overstories are wider and higher. They cast a far longer shadow on the ground beneath them.
The problem was not that people were denying the Holocaust, claiming it never happened. It’s because they didn’t know about it. Or they knew about it but didn’t want to talk about it.
Even within the Jewish community—and among survivors, in particular—there was a reluctance to talk publicly about what had happened.
Liberals, moderates, and conservatives, in most cases, disagreed strongly on hot-button issues only if they didn’t watch a lot of television. But the more television people of all ideological persuasions watched, the more they started to agree. When a large group of people watch the same stories, night after night, it brings them together.
there is something about a revolution—large or small—that baffles us: When a group of people come together, in a fever, and abruptly change the way they behave or what they believe, we are suddenly at a loss for words or understanding.
We miss the signs of change because we are looking for them in the wrong places.
Think about the psychology of that kind of change. “If you’re just below that tipping point—you’re at 20 percent—you have no idea how close you are,” Centola says.
If change happened gradually, you could see that you were getting closer and closer to your goal—and you wouldn’t be surprised when you reached it. But if nothing happens and then everything happens, you are in the strange position of being discouraged during the long stretch when nothing is happening and stunned at the point when it all shifts.
Jessica Ho’s chart tells us that the opioid crisis is not really an international problem. It’s fundamentally an American problem.
What began as one man’s idiosyncratic crusade turned into a national phenomenon. States around the country began reaching into their doctors’ medicine cabinets and telling them that when it comes to this drug and this drug and this drug, You cannot be left to your own devices. A policy turned into an overstory.
That’s the nature of an overstory: Most of us don’t bother to look up at the ideas circulating above in the forest canopy.
