Benjamin Franklin had already turned 70 by the time he signed the US Declaration of Independence in 1776, when the average man wasn't expected to live to see 34. The inventor and statesman's remarkable longevity - he died at the age of 84 - has been attributed to avoiding alcohol and avidly swimming.
Global life expectancy at birth has now topped 70 years for men, and 75 years for women. And the population living to 100 and older is predicted to grow to nearly 3.7 million by 2050, from just 95,000 in 1990. According to a study published earlier this year, the biological "hard limit" on our longevity - barring disease and disaster - is as high as 150 years.
The progress made on extending lifespans thanks to vaccines and other breakthroughs has created complications, like difficulty funding retirement for growing elderly populations in some places. But it's also inspired people to imagine a future where they pursue multiple careers and effectively combine several lives into one.
At certain points our prospects for longer lives haven't looked great; US life expectancy saw its biggest decline last year since at least World War II, as Covid-19 was added to ongoing problems like drug overdoses. France, too, suffered a drop in life expectancy in 2020.
But there are clear indications more of us are headed the way of Jeanne Calment, the French woman who may have reached the age of 122 before dying in 1997.
Questions have been raised about Calment's true longevity, but researchers from France and Switzerland say she was the oldest human being. Regardless, her official biography has captured the fancy of those who like the idea of being able to sip Port wine and eat more than two pounds of chocolate per week well past the century mark.
Clearly, the attractiveness of a longer life hinges on its quality.
The researcher Aubrey de Grey argues that the cellular decay behind ageing will be defeated. He's popularized the term "Methuselarity" to describe the point after which people with access to the right therapies will no longer suffer from age-related health problems, and human longevity will reach "escape velocity" (de Grey said recently that chances are decent this will occur by 2036).
Ray Kurzweil, an inventor and futurist, has likened the human genome to outdated software, and described ageing as a solvable engineering problem. Eventually we could extend our longevity "indefinitely," Kurzweil has said, and relatively soon it may be possible to start adding one additional year to our lifespan every year.
There are potential economic benefits if people become able to live longer while staying healthier. A study published earlier this month used data from the US to suggest that effectively slowing the typical ageing process could create $38 trillion in value in a year of added life expectancy.
However, it's unclear how evenly the tools needed for living longer and healthier lives would be distributed. Disparities in terms of healthcare and longevity, even within relatively wealthy countries, have become stark.
The OECD, a group of economically advanced countries, has reported that in 25 of its member states people with the highest level of education can expect to live about six years longer than those with the lowest level of education at age 30, for example.
The potential for effective anti-ageing innovation to worsen inequality in the future has stirred debate - some say the advantages the affluent already have in acquiring everything from youth-preserving serums to face cream provide a glimpse of the issues to come.
For more context, here are some observations from the World Economic Forum's Strategic Intelligence platform:
This study found a link between longer times required to conceive a child and shorter lifespans for women - a potential concern for the estimated 15 per cent of couples in industrialized countries who now require more than a year.
There may be a scientific basis for assuming the more stress you avoid, the longer you'll live; according to this study, a gene that protects brain stem cells from harmful effects of stress is linked to unusually long lifespans.
Can Africa help Europe avoid its looming ageing crisis? According to this analysis, bringing more women and older workers into the labour market won't be sufficient, making migration the only workable solution.
One potential way to slow the ageing process, according to this study: avoid exposure to pollutants like cigarette smoke, alcohol and pesticides.
There's a difference between "chronological" and "biological" ageing, according to this piece. The latter seems to be poised to slow dramatically for many people, and that could create serious challenges.
According to the "Gompertz equation" our odds of death from something like cancer or heart disease roughly double every eight to nine years, but this analysis argues that traditional methods of calculating lifespan don't account for new medical discoveries.
The piece is excerpted from www.weforum.org