Why We Live Longer — and Can Still Live Better
The Stanford Center on Longevity says we can improve the aging process for everyone
Laura L. Carstensen is professor of psychology and the Fairleigh S. Dickinson Jr. Professor in Public Policy at Stanford University. She is also the founding director of the Stanford Center on Longevity, which explores innovative ways to solve the problems of people over 50 and improve the well-being of people of all ages.
We as a society are growing older, but that’s not really the same as being old, if your standard is the stereotypical physical and mental tribulations that word has long implied. Instead, old age now mostly means we have more years on the clock than did our forbearers. A lot more.
The world has more "old" people today than at any time in human history. Does it matter? Very much. We believe that unprecedented changes in the age structure of society are on track to affect every aspect of life as we know it.
The History of Aging
Looking at this shift from a historical perspective, humans living multidecade lives is a very recent phenomenon. Scientific consensus holds that during most of human evolution, life was short. With a life expectancy of between 18 and 20 years, these early humans were already elderly long before the prime creative and productive years of today’s adults. They rarely got to see their sons and daughters emerge from childhood.
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It took tens of thousands of years for people to add just a few extra birthdays to their lives. Civil War-era Americans, for example, lived on average into their mid-30s, still a population of very young oldsters by today's standards. To be sure, average life expectancy at the time was greatly affected by the prevalence of early-childhood deaths and many people lived well past their 30s. But death was more common at all ages than it is today. To note just one example, many more women died of childbirth at that time.
By 1900, after the Industrial Revolution's momentum, average life expectancy had climbed to 47. Then came an unprecedented boom in life span, powered by historic improvements in health care from early childhood through old age. As the 20th century gave way to a new millennium, people were living roughly four times longer than their caveman ancestors. In the United States alone, life expectancy shot up to 77, a near-unthinkable 30-year jump in a single century.
Our New Old Age
Now, each and every day, an average of 10,000 Americans turn 60 and join what some consider the ranks of the "old." Or do they? Increasingly people don't think of themselves as old at 60, or 65, for that matter. They have reason not to: They bear little resemblance, after all, to the sedentary, infirm elderly people they encountered in their childhoods. To the contrary, the new elderly often engage in the same work and activities as when they were younger adults.
At the Stanford Center on Longevity, we are delving into what it means to be a member of this burgeoning population of the new old. Through our study of life-span development, we seek ways to use science and technology to improve the well-being of people over 50 and ideally all ages.
Our research is informed by the demographic trends that are dramatically changing the structure of our society. For example, we not only live longer today; we also give birth to fewer children. As life spans soared during the 20th century, the U.S. birth rate fell by nearly half. So not only do Americans live longer today, the average American is older.
What Drives Our Evolution?
Our extended lifespan is powered by science and technology. Nobel Prize-winning American economist Robert Fogel has referred to the phenomenon as technophysio evolution, or evolution prompted by technological advances rather than natural selection.
(MORE: Why Men Die Younger Than Women)
During the 20th century, improved agricultural technologies assured a reliable food supply, so people grew bigger and heartier. In 1850, the average American man stood about 5-foot-7, weighed about 146 pounds and lived to 45. In the 1980s the typical American man in his 30s was about 5-foot-10 inches tall, weighed about 174 pounds and could expect to reach his 75th birthday.
But technophysio evolution may be too narrow a term for what we’re experiencing as a society. The changes in health and safety that have emerged over the past several decades represent nothing short of a cultural revolution. American and European food fortification programs built vitamins into the food supply. Milk was pasteurized. Water was purified. Cities and towns systematized garbage collection, removing historic sources of life-threatening disease. And new technologies — like refrigeration, which reliably kept food safe — became available to the masses.
At the same time, public education swept the nation, and local, state and federal governments enacted volumes of laws and regulations that transformed our quality of life. In other words, we built a society exquisitely designed to support young life and put our population on the right track toward a vital old age.
What Comes Next
Today's adults are reaping the benefits of that evolved world, our lives extended, our demographic niche expanding. By 2030, almost a quarter of the U.S. population will be over 65. There are signs of concern, though: Troubling new research shows that among some groups, life expectancy has actually declined since 1990. White women without a high-school diploma, for example, lost a full five years of life expectancy from 1990 to 2008, perhaps due to a combination of higher obesity and drug use, persistently high rates of smoking and an increase in the percentage of uninsured families among the least-educated white Americans. Still, scientists are confident that an older American society is here to stay.
Improved longevity is among humankind's most remarkable achievements, and it presents us with one of our greatest challenges. Our added years can be a gift or a burden, depending on how we use them.
Through our research into such subjects as the effect of premature birth on adult health, the center aims to unlock more secrets of the body's response to aging, and redesign long life. We want to turn longer life into an exhilarating opportunity, and change the way future generations live, starting on the day they are born.
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