Born after 1939? You’re unlikely to be a ‘centenarian,’ experts say. Here’s why
The era of celebrating grandma’s 100th birthday may be coming to an end.
Centenarians, or people who live to be at least 100 years old, are a small group of elderly elite who have beaten the odds to see 10 decades in their lifetime.
The century-plus club made up just 0.03% of the United States population in 2024, and previous estimates based on census data predicted that number could quadruple in the next three decades, according to the Pew Research Center.
But now, an international team of researchers say that increase is unlikely, and more recent generations are less likely to see their 100s than generations that came before.
“The unprecedented increase in life expectancy we achieved in the first half of the 20th century appears to be a phenomenon we are unlikely to achieve again in the foreseeable future,” study author Héctor Pifarré i Arolas, from the University of Wisconsin-Madison, said in an Aug. 27 news release. “In the absence of any major breakthroughs that significantly extend human life, life expectancy would still not match the rapid increases seen in the early 20th century even if adult survival improved twice as fast as we predict.”
The elderly elite
In order to forecast generational age life expectancy, researchers looked at cohorts from 23 “high-income” countries, according to a study published Aug. 25 in the peer-reviewed journal Proceedings of the National Academy of Sciences.
Including the U.S., researchers examined data between 1939 and 2000 from Australia, Austria, Belgium, Canada, Denmark, Germany, West Germany, England and Wales, Finland, France, Iceland, Ireland, Italy, Japan, Netherlands, Northern Ireland, Norway, Portugal, Scotland, Spain, Sweden and Switzerland, according to the study.
Before 1938, researchers said the average life expectancy in these regions increased about 5.5 months for each generation, according to the release. From 1900 to 1938, life expectancy jumped from 62 years to 80 years.
A lot of this change can be attributed to medical advances that decreased infant mortality, allowing more people to live into adulthood, researchers said.
Now that the infant death rate has stayed low in high-income countries, it no longer plays a part in increased life expectancy over generations, researchers said.
Between 1939 and 2000, the generational life expectancy increase was smaller, with each generation adding just 2.5 to 3.5 months to their total, according to the release.
That value is decelerating, researchers said, meaning each generation is adding less time than the last.
“We forecast that those born in 1980 will not live to be 100 on average, and none of the cohorts in our study will reach this milestone,” study author José Andrade of the Max Planck Institute for Demographic Research said in the release. “This decline is largely due to the fact that past surges in longevity were driven by remarkable improvements in survival at very young ages.”
‘Recalibrate their expectations’
Pending a breakthrough in research that leads to a cure for cancer or heart disease, the leading causes of death in the U.S., the rate will continue to decrease each generation, according to the study. This means there won’t be a boom of people living older, and the average will stay about the same.
The current average life expectancy in the U.S. is 78.4 years, with men slightly younger at 75.8 and women living longer at 81.1 years, according to the Centers for Disease Control and Prevention.
Americans live shorter lives than their European equivalents, McClatchy News reported in April, but the trend of stagnant life expectancy appears to be afflicting European nations the same, according to the study.
Life expectancy can be impacted by pandemics, new medical treatments and societal changes, the researchers said, but these factors can’t be predicted in these long-term models.
“Although a population-level analysis, this research also has implications for individuals, as life expectancy influences personal decisions about saving, retirement and long-term planning,” according to the release. “If life expectancy increases more slowly as this study shows is likely, both governments and individuals may need to recalibrate their expectations for the future.”
The research team includes Arolas, Andrade and Carlo Giovanni Camarda.
This story was originally published September 2, 2025 at 2:31 PM with the headline "Born after 1939? You’re unlikely to be a ‘centenarian,’ experts say. Here’s why."
