Vannevar Bush, the head of the U. S. Office of Scientific Research and Development during World War II, tells the story of how during the war he was trying to gain more funding from Congress for medical research. Hoping to further his cause, he convinced A. Newton Richards, President Roosevelt's chairman of the Committee on Medical Research, to testify in favor of more funding before a Congressional committee. As Bush recounts, "It was towards the end of the war, and Richards was feeling tired and a bit old. One of the congressmen asked him, 'Doctor, will all these researches you are carrying on tend to lengthen the span of human existence?'
'God forbid,' said Richards, smack into the record."
While not every medical researcher shares Dr. Richard's reluctance to lengthen human longevity, Dr. Jan Vijg of the Albert Einstein College of Medicine thinks he has discovered the true limit to how long humans can live. It's about 115 years, he says.
According to a recent New York Times report, Dr. Vijg and his colleagues studied the mortality records of a number of countries to see which age group experienced the most rapid growth in recent decades. As the general level of health care in industrialized countries has improved, the average lifespan has increased, but Dr. Vijg guessed that if there was a natural limit, it would show up first in the leveling off of the age of the fastest-growing group of old people. For example, in the 1920s in France, 85-year-olds were the fastest-growing group, but by the 1990s that honor belonged to 102-year-olds. In the last decade or so, the trend has stagnated at about 115. There are exceptions, of course, such as Jean Calment, who before her death in France in 1997 at age 122 was fond of retelling her recollections of meeting Vincent Van Gogh. But statistically, Dr. Vijg has strong evidence that no matter what specific diseases we conquer, we have a built-in expiration date of about 115 years.
Lots of people disagree with Dr. Vijg, of course. One of the scientists who collected data used in Dr. Vijg's study deplores his conclusion, calling it a "travesty." But we should distinguish between a descriptive study, whose purpose is simply to give us insight into what is in fact happening, and a claim of proof. Not even Dr. Vijg is claiming to have proved nobody can live longer than 115, if for no other reason than the fact of Ms. Calment's achievement. What he presents is persuasive statistical data that, unless we discover the root causes of aging and get a handle on how to manipulate them, we are unlikely to push the maximum lifespan higher than 115.
It's curious, but a friend of mine has been going around for some time claiming approximately the same thing on the basis of a sermon he heard. I didn't hear the sermon, but evidently the preacher was looking forward to living to 120 on the basis of a Bible verse in the Old Testament.
He was probably talking about Genesis 6:3, which reads in the King James Version, "And the Lord said, 'My spirit shall not always strive with man, for that he also is flesh: yet his days shall be an hundred and twenty years.'"
Now, this passage occurs in the midst of a number of other sayings that are, to say the least, hard to interpret—things about the sons of God marrying the daughters of men, giants in the earth, and so on. Some interpreters say this passage has nothing to do with a limit on human lifespans; rather, it refers to the time during which God put up with man's increasing misbehavior before he decided to put an end to it with the Flood, which only Noah and his fellow shipmates survived.
Whatever the meaning of the Genesis passage, it has historically been a truism that everyone's going to die sooner or later, and society has been arranged with that assumption in mind. Dr. Vijg's claim that we shouldn't expect to live longer than 115 years or so just confirms what nearly everyone assumes, and puts a number on it.
However, these ideas are rejected by a small but vociferous group called transhumanists, who increasingly put their faith in the idea that humanity is shortly going to figure out how to extend useful, fruitful life indefinitely. They don't always say "forever," but many of them mean that. One type of transhumanists called "immortalists" in particular seem to think that we can figure out how to live forever. While I understand why a person, especially one who doesn't believe in God, would get interested in extending human life—it's the only show in town, on their view—the danger in this movement is that in trying to move us toward a glorious paradisacal future, they will unwittingly turn the present into Hell on earth. This sort of thing went on during the Cold War, and continues in some places today, as millions were subjugated by Communist regimes which promised a wonderful future of abundance at the price of sacrificed freedoms now. Lest we dismiss the transhumanists as a powerless fringe group, one of their leading lights, Ray Kurzweil, currently holds a high-level position at Google.
Perhaps the best thing is not to focus just on how long we can live, but how long we can live well. Dr. Vijg takes this approach, saying that even if there is a natural limit of 115, there's a lot we can still do to prevent diseases such as Alzheimer's, osteoporosis, and other age-related maladies from robbing us of the enjoyment of those later years. So the news that we can't live past 115 is not a counsel of despair, by any means. Still, for those who think death is the end, it's not good news either.
However long one lives, the length matters less than what you do with it. Old paintings of philosophers would sometimes show a human skull prominently displayed in the philosopher's study. It represents a reminder that life is limited, and every minute is one of a finite number of minutes we will have, so we should make the most of them. Some of the best advice along these lines, for believers and non-believers alike, is from Psalm 90, which says "So teach us to number our days, that we may apply our hearts unto wisdom."