Will Oremus finds evidence that humans have hit a lifespan ceiling:
Life expectancies in most countries not ravaged by AIDS have been rising gradually for decades, and the average American today can expect to live 79 years—four years longer than the average in 1990. In many developed countries, the superold are among the fastest-growing demographics. (There is evidence that this progress may be grinding to a halt among some demographics, however.) But raising the upper bounds of the human lifespan is turning out to be trickier than increasing the average person's life expectancy. This may be a case where, as with flying cars, a popular vision of technological progress runs afoul of reality's constraints.
In the past few years, the global count of supercentenarians—people 110 and older—has leveled off at about 80. And the maximum age hasn't budged. Robert Young, senior gerontology consultant for the Guinness Book of World Records, says, "The more people are turning 110, the more people are dying at 110."
Robert W. Fogel is more optimistic.
(Photo: Candles burn atop the birthhday cake of Walter Breuning, the 'World's Oldest Man,' during his 113th birthday celebration on September 21, 2009 at the Rainbow retirement home in Great Falls, Montana. Breuning, born Sept. 21, 1896 in Melrose Minnesota, inherited the title of 'World's Oldest Man' when Henry Allingham of England died July 18, 2009. Breuning died on April 14, 2011. By John Moore/Getty Images)
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