Mortality and Life Expectancy
Why 'People Used to Die Young' Is Mostly a Myth
The ancient Romans didn't live short lives — they just had a catastrophic problem with keeping babies alive.
The Idea
When historians quote an average life expectancy of 25–35 years for pre-modern societies, they are technically correct and almost entirely misleading. That number is a mean dragged violently downward by infant and child mortality. If you survived your fifth birthday in ancient Rome — or medieval England, or colonial-era anywhere — your odds of reaching your fifties or sixties were actually reasonable. Reach 60 and you might well see 75. This distinction matters enormously. It means that Cicero at 63, Michelangelo at 88, and the grandmother burying her grandchildren weren't statistical freaks. They were simply people who had cleared the brutal early-life filter that killed perhaps one in three children before age five in most pre-industrial societies. Life expectancy at birth is a useful public health metric today precisely because infant mortality is now so low that the number genuinely reflects adult experience. Before the 20th century, it reflects almost nothing about how long adults actually lived — it mostly measures how many infants died. The real revolution in modern longevity isn't that we've dramatically extended old age; it's that we've saved the children. Average life expectancy has roughly doubled in the last 150 years, but most of that gain came from the bottom of the age distribution, not the top. An elderly person today lives perhaps a decade longer than their counterpart in 1800. But they were never the crisis. The infants were.
In the World
In the 1840s, a Hungarian physician named Ignaz Semmelweis noticed something quietly horrifying in the maternity wards of Vienna General Hospital. Women giving birth in the ward staffed by medical students and doctors were dying of puerperal fever at roughly five times the rate of those in the ward staffed by midwives. The difference, he eventually realised, was that doctors were coming directly from performing autopsies — and washing their hands with nothing more than water. When Semmelweis introduced chlorinated lime handwashing, mortality in his ward dropped from around 10 percent to below 2 percent almost immediately. He had, with one procedural change, saved hundreds of lives a year in a single hospital. His story is usually told as a tragedy — he was ridiculed by the medical establishment and died in an asylum — but it is also a precise illustration of how pre-modern mortality actually worked. It wasn't that people aged and died faster. It was that they died from infections, from childbirth, from contaminated water, from wounds that in any modern setting would be trivially treatable. Remove those causes of death — as the sanitation revolution and germ theory gradually did across the late 19th and early 20th centuries — and lifespans don't just creep upward. They leap, because you've removed the catastrophic early exits that were always distorting the average.
Why It Matters
This isn't just a statistical correction — it reframes how you think about progress, history, and the lives of the people in it. When we imagine the ancient world as one of short, brutal lives, we unconsciously write off the depth of human experience that clearly existed there: long friendships, generational memory, accumulated wisdom. Sophocles was writing plays in his nineties. Titian may have lived past 90. These weren't exceptions to be marvelled at. They were what happened when you survived early childhood. It also sharpens the way you read modern health statistics. When a country's life expectancy rises or falls, the most powerful lever is almost always what's happening to the youngest — infant mortality, childhood disease, maternal death. A society can have thriving, long-lived adults and still register a shockingly low average if its youngest members are dying at high rates. And perhaps most usefully: it reminds you that averages hide everything that is interesting about a distribution. The number 35 tells you almost nothing about a Roman life. What you actually want to know is the shape of the curve — and in history, that curve has almost always been the same story: survive the beginning, and you might just last.
A Question to Ponder
If most of what we call 'modern longevity' is really just saved childhoods rather than extended old age, what does that imply about the limits we might be approaching — and whether there's still a genuine frontier left to push?
Get a new one of these every morning.
Start learning with Thinkable