Adding Decades Like It's Nothing
Global average life expectancy in 1800: about 29 years.
Now, before the pedants jump in — no, that doesn't mean everyone dropped dead at 29. It means that so many people died as infants and children that the average got crushed down. If you survived to adulthood in 1800, you had a reasonable shot at making it to your 50s or 60s. But "if you survived to adulthood" was doing an enormous amount of heavy lifting in that sentence, because a huge percentage of people didn't.
Even stripping out infant mortality, adult life expectancy was still dramatically lower than today. Surgery was butchery. Infection was a death sentence. Chronic diseases were poorly understood and untreatable. A broken bone could be a life-ending event if it got infected. Childbirth was one of the leading causes of death for women. And "old age" started somewhere around 50.
By 1900, global life expectancy had climbed to around 32 — a modest gain driven largely by improved sanitation and the beginnings of public health. By 1950, it was 46 — antibiotics and vaccines were starting to reshape the curve. By 2000, it was 67. Today it sits at approximately 73 years globally (WHO).
In the United States, life expectancy is around 77 (it took a dip during COVID and is recovering). In Japan, it's over 84. In Spain, Italy, Switzerland, and several other countries, it's over 83. In South Korea, which was one of the poorest countries on Earth in the 1950s, life expectancy has gone from about 47 in 1960 to over 83 today — an increase of 36 years in a single human lifetime.
We added more years to average human life in the last century than in the previous five thousand combined.
Think about what made this possible, because no single intervention gets the credit. Clean water and sewage systems eliminated waterborne diseases that had killed millions annually. Vaccines wiped out or dramatically reduced childhood killers like smallpox, polio, measles, and diphtheria. Antibiotics — available only since the 1940s — turned bacterial infections from death sentences into minor inconveniences. Modern surgery, anesthesia, blood transfusion, and sterile technique made it possible to fix things inside the human body that would have been unsurvivable a century earlier.
Prenatal care and hospital births slashed maternal and infant mortality. Refrigeration improved nutrition year-round. Pasteurization made milk safe to drink — something we take so completely for granted that most people don't even know milk used to be a vector for tuberculosis, typhoid, and scarlet fever. Public health campaigns against smoking have prevented millions of premature deaths. Statin drugs, blood pressure medications, and improved cardiac care have cut heart disease mortality by more than half.
Each one of these would have been considered a miracle in any prior century. Together, they've effectively doubled the human lifespan within living memory.
And the gains aren't limited to rich countries. Bangladesh, one of the world's poorest countries, has seen life expectancy rise from 46 in 1970 to about 73 today — nearly matching the global average. Ethiopia has gone from 41 to about 66 in the same period. India from 49 to about 70. These aren't wealthy nations with unlimited healthcare budgets. These are countries where basic public health measures — vaccines, oral rehydration therapy, clean water, antibiotics — have added decades to average human life within a single generation.
We went from a world where dying in your 40s was normal to one where dying in your 60s feels premature — and we did it so fast that people have already started taking it for granted.
My grandparents' generation considered it a good outcome to make it to 60. My generation reasonably expects to see 80. My kids' generation may well see 90 as routine. And the frontier keeps moving — research into aging itself, gene therapy, precision medicine, and AI-driven drug discovery are all pushing at the boundaries of what's possible.
We went from a world where dying in your 40s was normal to one where dying in your 60s feels premature — and we did it so fast that people have already started taking it for granted. Nobody wakes up in the morning and thinks, "Thank God for clean water, antibiotics, and modern obstetrics." But they should. Because without them, a huge percentage of us wouldn't be here at all.