Eric Fougére/Kipa/Corbis
It’s one of humanity’s longest-standing questions: How long can we live? Even the Bible weighs in. But people, on the whole, seem to be natural pessimists when it comes to the answer. Time after time, experts have estimated a maximum possible life expectancy that any human population could achieve. Time after time, we’ve exceeded it.
In fact humans’ longevity gains have been startling — and the trend toward ever-longer lifespan still, to date, shows no signs of slowing. The best evidence of this was published a few years ago in the journal Science. A paper by scholars Jim Oeppen and James Vaupel showed that life expectancy in the world’s highest-life-expectancy country — which can change from year to year, obviously — has been increasing by about 2.5 years per decade since the mid-19th century. That’s an incredible rate of progress. The world’s best observed life expectancy, in other words, is increasing at a rate of of three months every year. Or, as Vaupel puts it, “six hours per day!” Even more surprising: this trend has been extraordinarily consistent, with very little variation in the gains from one year to the next. And, as mentioned above, it shows absolutely no signs so far of slowing.
The historical record does lead to a conclusion that seems counterintuitive then. Surely, after all, at some point humans have to hit a maximum age, beyond which we’re just not genetically designed to survive. Oeppen and Vaupel show that no less than one dozen such hypothesized maximum life-expectancy limits have already been exceeded. Experts have warned that life expectancy is near its natural limit since the 1920s, and in most cases the assumed maximum was surpassed less than one decade after the projection was first made.
So how high could life expectancy go? There’s no way to know. The oldest that a person has ever lived (at least with verified records) was Frenchwoman Jeanne Calment, pictured above, who died at 122. It does seem tough to believe that people could ever routinely live to be that old. But if a biological maximum does exist — as it very well might — there’s good evidence to suggest that we’re not yet close to hitting it.