How Humans' Lifespans Doubled in Less Than a Century

We tale it for granted now that we are probably going to live to be seventy or eighty. For most of human history, it wasn't like that. Most people died before they were fifty, even if they managed to survive childhood. In the last century, the average lifespan has doubled. 

There is a long article in the New York Times that analyses the reasons behind this amazing change and looks at what the future might bring. It's worth taking the time to read.

The period from 1916 to 1920 marked the last point in which a major reversal in global life expectancy would be recorded. (During World War II, life expectancy did briefly decline, but with nowhere near the severity of the collapse during the Great Influenza.) The descendants of English and Welsh babies born in 1918, who on average lived just 41 years, today enjoy life expectancies in the 80s. And while Western nations surged far ahead in average life span during the first half of the last century, other nations have caught up in recent decades, with China and India having recorded what almost certainly rank as the fastest gains of any society in history. A hundred years ago, an impoverished resident of Bombay or Delhi would beat the odds simply by surviving into his or her late 20s. Today average life expectancy in India is roughly 70 years.

In effect, during the century since the end of the Great Influenza outbreak, the average human life span has doubled. There are few measures of human progress more astonishing than this. If you were to publish a newspaper that came out just once a century, the banner headline surely would — or should — be the declaration of this incredible feat. But of course, the story of our extra life span almost never appears on the front page of our actual daily newspapers, because the drama and heroism that have given us those additional years are far more evident in hindsight than they are in the moment. That is, the story of our extra life is a story of progress in its usual form: brilliant ideas and collaborations unfolding far from the spotlight of public attention, setting in motion incremental improvements that take decades to display their true magnitude.