If you were born in 1900, you had a pretty good chance of dying by your 50th birthday. Today, thanks to improved health and safety around the world, that would be — in many countries — a life cut short by at least a few decades.
“The dramatic increase in average life expectancy during the 20th century ranks as one of society’s greatest achievements,” notes a report from the National Institute on Ageing, a division of the National Institutes of Health.
That dramatic increase — approximately three additional months in life expectancy each year — is clear in the chart below (which looks only at women in a subset of developed countries, though trends are similar among men):
These gains have not been universal; the average life expectancy in the world’s least developed countries is still about 61.
But overall, people are living longer. A number of factors have contributed to this upswing in our longevity, including declining infant deaths, better management of infectious diseases, and more widespread access to clean water. In the decades leading up to the nineteenth century, much of the improvement in life expectancy was not because people were living into what we now consider old age — it’s because fewer children were dying before they reached adulthood.
In the 20th century, we finally began to see the trend that’s continuing now: fewer deaths at older and older ages.
The 85-and-over population is projected to increase 351% between 2010 and 2050.
The most interesting thing about that trend, the report notes, is that it was totally unexpected: “The progressive increase in survival in these oldest age groups was not anticipated by demographers, and it raises questions about how high the average life expectancy can realistically rise and about the potential length of the human lifespan.”
Most scientists agree that there is in fact a limit on how long, physically, we can live: rising averages aside, no one has ever been documented as living beyond 122. “Getting to about 110 is really approaching the limit of the human lifespan,” explains Thomas Perls, an attending geriatrician at Boston Medical Center and professor at the Boston University School of Medicine.
But while birth rates are dropping, average life expectancy is still rising, as more and more people live past 80, 90, and even 100. The population of people demographers call the “oldest old” is ballooning relative to other age groups — with no signs of slowing down.
The National Institute on Ageing report puts this in stark terms: “The 85-and-over population is projected to increase 351 per cent between 2010 and 2050, compared to a 188 per cent increase for the population aged 65 or older and a 22 per cent increase for the population under age 65.”
That should help explain why some people are in panic mode about Social Security.
“This is uncharted water,” one Pew researcher told The Atlantic.
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