Extra Life: A Short History of Living Longer

Imagine standing in the bustling streets of 17th-century London, where the air is thick with the scent of smoke and the sounds of merchants calling out their wares. In this world, the average newborn could expect to live only about seventeen and a half years, a figure that shocks us today but was a grim reality then. This number was not plucked from folklore but painstakingly calculated by early pioneers who dared to count and analyze the dead. These early demographers transformed scattered parish records into life tables, revealing the fragile nature of human life under the shadow of disease and hardship.

Yet, when we look beyond the city to the remote tribes of hunter-gatherers, we find a surprising truth: their life expectancy hovered around thirty to thirty-five years, not drastically different from the urban poor. This challenges the notion that primitive life was necessarily short and brutal in every sense. Many who survived the perilous years of childhood could live into their sixties or beyond, embodying resilience shaped by evolution.

But what of the wealthy? Paradoxically, in the 18th century, aristocrats often lived shorter lives than commoners. The reason lies in the realm of medicine, which, far from being a savior, was often a source of harm. Treatments like bloodletting, purgatives, and arsenic poisoning were common prescriptions, sometimes worsening patients' conditions. The story of a king suffering mental illness worsened by arsenic-laden remedies is a chilling reminder of the dangers of misguided medical practice.

This era, known as the age of heroic medicine, was marked by bold but often fatal interventions. It was not until the gradual rise of public health, improved nutrition, and sanitation that this ceiling on human lifespan began to crack. The journey from counting deaths to understanding life expectancy set the stage for the remarkable advances that would follow.

As we close this chapter on the origins of measuring human life, we prepare to delve into the first great breakthrough that allowed humanity to push back against death itself: the discovery and spread of vaccines.