Longevity

• Also known as: Life span, life expectancy
• Anatomy or system affected: All

Definition: A broad concept that encompasses the progressive biopsychosocial changes associated with advancing age. The average lifespan expected based on current mortality rates in a population.

Key term:

life expectancy: the average lifespan expected of a group

Overview

Lifespan or life expectancy are terms that are often used synonymously with longevity, but the terms are not identical: life expectancy is used more commonly when referring to demographics and population data, lifespan refers to the maximum potential length of life, and longevity is a broader term describing the duration of life.

It has been speculated that with age comes wisdom: the culmination of years of experience, memories, and lessons learned informs a person’s perspective on life and what kind of legacy one wants to leave behind. Conversely, the process of aging also increases a person’s risk of dying: Many theories suggest that years of physical and emotional (internal) and environmental (external) influences render a person more susceptible to acute illness or the development of chronic disease. Modern medicine—pharmaceuticals, therapies, technology—has the capability to extend life well beyond previously held norms. According to the Centers for Disease Control and Prevention, in 2023, the average life expectancy in the United States at birth was 81.1 years for women and 75.8 years for men. The US Census Bureau has also reported that the 65-and-older population was the fastest-growing population in much of the developed world, growing by over a third between 2010 and 2019. This trend also continued into the mid-2020s: by 2020, the US population aged 65 years and older had reached 55.8 million, and by 2024, there were about 62 million adults aged 65 and older in the country. With the technological advances that have been made, it begs the relevant question: Can aging be cured? And if it can, should it?

The concept of longevity, the progression from birth to death, has been recognized by human beings for hundreds of years, but the ethical discussion of whether or not we should exercise the right to live as long as possible is a relatively new one. Charles Darwin, the English naturalist and major contributor to the theory of human evolution, would argue that death is the result of natural selection, a process that is expected and a natural happenstance when adverse events suffered outmatch the ability of the body to sustain life. Longevity has also been explored in fictional literature. Shakespeare often depicted a person’s life as a series of “roles” acted out on the societal stage, roles that are gradually lost as old age progresses until death finally arrives—the final act. Less metaphorically, Jonathan Swift’s popular novel Gulliver’s Travels (1726) relates the story of the Struldbrugs, a nation of humans that never die but still suffer the ravages of time and advancing age, eventually blind, cognitively impaired, and physically disabled, as the body deteriorates but death never arrives—living but not living. While graphic and extreme, perhaps modern-day Struldbrugs can be identified in hospitals across the developed world as machines and technology are often utilized to sustain quantity of life but do little to preserve quality of life.

Further inquiry in the fields of population biology, psychology, ethics, and anthropology continues to provide new insights into the evolving concept of longevity.

Longevity Claims

Statista and the US Census Bureau reported that in 2021 there were approximately ninety-seven thousand centenarians (those who are aged 100 years or older) living in the United States. The number of centenarians increased to 101,000 in 2024, with the US Census Bureau estimating about 422,000 by 2054. Researchers, scientists, and medical professionals agree that one's life span is greatly determined by a combination of genetics, lifestyle, and mental and physical health, but the longer one lives, the more genetics come into play. One study indicated that while no specific longevity gene seemed to contribute to an extremely long life, multiple genetic factors have been associated with longevity, and individuals who lived to age 110 and beyond all seem to have been able to delay any serious medical condition or disease until later in life. In other words, they all share the quality of having several of the "right" genes that protected them from developing serious illness until much later in life. The study further noted that the older the individual, the shorter their periods of disability and disease. This compression of morbidity hypothesis is the notion that the onset of illness and disability can be delayed, resulting in a shorter period of poor health near the end of life. It is believed that future genetic testing and study of supercentenarians can help scientists to discover new and effective treatments for diseases such as cancer and heart disease.

Individual claims of longevity and reaching supercentenarian status were once difficult to confirm because of scientific and research constraints. Still, groups such as Guinness World Records and the Gerontology Research Group (GRG) are dedicated to verifying such claims. L. Stephen Cole, cofounder of the Gerontology Research Group, states that this list of supercentenarians, which is updated regularly, averages about seventy entries. Individuals claiming to be aged 110 or older must first prove their age with two to three pieces of documentation before they are added to GRG's database. Cole admits that there are most likely many true supercentenarians who do not make GRG's list only because they cannot provide the necessary documentation. China and India, for example, expanded and standardized national systems for tracking birth and death records during the early twentieth century, although record-keeping practices varied by region and period.

Bibliography

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Buchholz, Katharina. "Is 100 the New 80?: Centenarians Are Becoming More Common." Statista, 5 Feb. 2021, www.statista.com/chart/18826/number-of-hundred-year-olds-centenarians-worldwide. Accessed 25 Mar. 2026.

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Schaeffer, Katherine. “U.S. Centenarian Population is Projected to Quadruple over the Next 30 Years.” Pew Research Center, 9 Jan. 2024, www.pewresearch.org/short-reads/2024/01/09/us-centenarian-population-is-projected-to-quadruple-over-the-next-30-years/#:~:text=The%20number%20of%20Americans%20ages,How%20we%20did%20this. Accessed 25 Mar. 2026.

Sebastiani, Paola, et al. "Genetic Signatures of Exceptional Longevity in Humans." PLoS ONE, vol. 7, no. 1, 2012, doi: 10.1371/journal.pone.0029848. Accessed 25 Mar. 2026.

"65 and Older Population Grows Rapidly as Baby Boomers Age." US Census Bureau, 25 June 2020, www.census.gov/newsroom/press-releases/2020/65-older-population-grows.html. Accessed 25 Mar. 2026.

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