Throughout most of the seventeenth century, residents of London could buy, from street hawkers who fought one another for sales territory, a peculiar sort of newspaper. It cost a penny, sold about five or six thousand copies a week, and consisted of a single page. On one side, readers would learn how many of their neighbors had died the previous week, in each parish. On the other, readers would learn what was believed to have killed them.
“Jaundice” was common, as was “Apoplex,” an old word for a stroke, and “Dropsie,” which meant swelling. Other entries seemed to answer the question “How did he die?” with descriptions—“Dead in the Streets” or “Stilborn” or “Suddenly”—instead of actual causes. The deaths were usually assessed and recorded by pairs of older women, who were employed by parishes to go to the local church whenever its bell tolled a death. During one February week in 1664, these searchers, as they were known, recorded three hundred and ninety-three burials across the city. Death causes and counts ranged from “Aged” (thirty-two victims) and “Consumption” (sixty-five) to “Scalded in a Brewers Mash” (one).
For the same reasons that today’s newspapers report coronavirus case numbers on their front pages, the London papers, known as Bills of Mortality, became particularly popular when disease swept through the city. During the 1665 plague, Samuel Pepys wrote in his diary about feeling saddened or cheered by the latest numbers from the Bills, while a contemporary named John Bell noted that the Bills allowed people to know “the places which are therewith infected, to the end such places may be shunned and avoided.” But most of the time, according to the London merchant John Graunt, the Bills were little more than matters of curiosity, especially if there were deaths that were “rare, and extraordinary in the week current.” He didn’t consider this to be odd or unseemly. Death, after all, was the most basic fact of life.
Eventually, though, Graunt began to wonder if the Bills could be put to “other, and greater uses.” He painstakingly collected and organized decades of the death records, creating long tables of numbers. These first known tabulations of population-level health data are now widely recognized as the birth of epidemiology. Graunt pored over them. What types of death were most common? Which groups did they afflict? Why did some causes spike at certain times, while others stayed fairly constant? And, most of all, what could a lot of separate, individual deaths, taken together, tell him about the society in which they occurred? Although Graunt wanted, as he put it in a treatise, to understand “the fitness of the Country for long Life,” he believed that it was in its deaths that he would find answers.
In “Extra Life: A Short History of Living Longer” (Riverhead), Steven Johnson credits John Graunt with creating history’s first “life table”—using death data to predict how many years of remaining life a given person could expect. (One Dutch contemporary, a proto-actuary, took Graunt’s tables a bit too literally, writing confidently to his brother, “You will live to until about the age of 56 and a half. And I until 55.”) In fact, Graunt’s estimates were more of a guess than a calculation: when he wrote his treatise, in the sixteen-sixties, the Bills of Mortality didn’t record people’s age at death, and they wouldn’t for another half century. Yet his guesses about survival rates for different age groups turned out to be remarkably accurate in describing not just London at the time but humanity as a whole. For most of our long history as a species, our average life expectancy was capped at about thirty-five years.
Johnson calls this phenomenon “the long ceiling.” Analysis of ancient burial sites, of modern people living in hunter-gatherer societies, and of pre-industrial city dwellers all tell a similar story, Johnson writes: “Human beings had spent ten thousand years inventing agriculture, gunpowder, double-entry accounting, perspective in painting, but these undeniable advances in collective human knowledge had failed to move the needle in one critical area.”
That began to change in the eighteenth and nineteenth centuries. In what the economist Angus Deaton has named “the great escape,” average life expectancies broke the ceiling: what had been a very long, flat line finally rose, at first gradually and then dramatically. Between the Spanish flu of 1918 and the coronavirus pandemic of 2020, global life expectancy doubled. These developments, Johnson argues, should be printed in newspaper headlines and hawked on street corners like the old Bills of Mortality. Extra, extra: The average human has received thousands and thousands of extra days in which to live.
Johnson tries to account for those days. Which scientific or civilizational advancements should we thank for them? He groups innovations by those which have saved millions of lives (this list begins with the AIDS cocktail, anesthesia, and angioplasty), hundreds of millions of lives (here the roster goes from antibiotics to pasteurization), and, finally, billions of lives, a small but illustrious pantheon of three: artificial fertilizer, hygienic plumbing, and vaccines.
Johnson gives a hasty tour of the stories behind a few of these life-giving innovations. He explains how centuries-old practices in China, India, and the Middle East eventually inspired a vogue for smallpox variolation among the British aristocracy in the eighteenth century—even then, you needed an influencer to start a trend. And he returns to the same well, or, rather, pump handle, that featured in his 2006 book, “The Ghost Map,” about the disease detectives who investigated a cholera outbreak in the early days of germ theory. Yet he cautions that it’s shortsighted to think of these advancements in terms of a few brilliant geniuses having eureka moments.
Instead, the innovations that have saved the most lives are the product of piecemeal improvements, built on networks of support and inspiration, and spread by social movements. Most were not blockbuster therapies or expensive medicines but unsexy, low-tech ideas, like water chlorination or better techniques for treating dehydration. Almost none, he points out, came from profit-seeking companies. And many were just advancements in basic bureaucracy—the creation of public institutions that could systematically track health data, require that drugs be tested and regulated, or enforce simple safety measures.
The most effective changes have to do with saving the lives of children. When Graunt analyzed London deaths, he estimated that, for every hundred children conceived, “about 36 of them die before they be six years old.” Twenty-four more died before reaching the age of sixteen, fifteen more before turning twenty-six, and so on, the rate of attrition falling slightly with each decade until “perhaps but one surviveth 76.” For much of human history, our early years were so stalked by disease and infection and diarrhea that between a third and a half of us never escaped our own perilous childhoods. Especially in the long years before smallpox was eradicated, Johnson writes, “being a child was to forever be on the brink of death.”
And the peril was universal. Before the advent of proper hygiene and effective medicine, the children of the élite died just as often and just as early as those of the poor. The rich may even have died more often, since they could pay for the treatments of the time, which generally did them more harm than good. (Readers are given grim descriptions of the illnesses of George III and his foe George Washington, both of whom were made sicker by the “medical” care they received, and reminded that George III became king only because the Stuart line had ended with Queen Anne, a half century earlier. Despite her wealth and power, and despite eighteen pregnancies, only one of her children survived past the age of two—and he died at age eleven.) Extra life was one thing money could not buy.
But that equality of loss would soon change. Deaton showed that the great escape was accompanied by another trend, which is now known as “the great divide.” In the past couple of centuries, as changing conditions increased life expectancies within wealthy nations, average life expectancies in poorer ones—the ones bearing the brunt of imperialism, resource extraction, and disease imposed by the wealthy—got shorter. Eventually, average lives lengthened around the world, narrowing the gap, but they still lengthened substantially more for some people, in some places, than for others. “Of all the forms of inequality,” Martin Luther King, Jr., said in 1966, by which time the divide was entrenched, “injustice in health is the most shocking and the most inhuman.” Even in modern American cities, people born into poor neighborhoods can expect to live as many as thirty years fewer than people who are born in affluent ones across town. And that was before the covid-19 pandemic further widened our existing gaps.
