When US President Joe Biden’s extended family descended recently on Camp David, the rustic presidential retreat in the Maryland hills not far from Washington, D.C., it wasn’t just to go horse riding or shoot some hoops.

Sure, they’d planned to do all sorts of fun stuff. The place was built for it. Franklin D. Roosevelt and Harry Truman had called it Shangri-la. There are golf carts to scoot between cabins and lodges. There’s a single-hole golf range. Skeet shooting. A pool. A cinema. A bowling alley. They’d even arranged with celebrity photographer Annie Leibovitz for a family photo ahead of the upcoming Democratic National Convention.

But by the time they’d all made it to the compound, any long-held plans were out the window. This was now a council of war. The mood, as they say, was grim.

What exactly had gone wrong with Biden just days earlier, in his catastrophic performance in the first presidential debate of this election campaign, on June 27, is still a mystery. He’d struggled to finish sentences, stumbled on facts and figures, appeared pale, wooden, even bewildered. He was all at sea trying to rebuff a lying, bragging Donald Trump.

“It was clear a political disaster was about to unfold as soon as the 81-year-old commander in chief stiffly shuffled on stage,” reported CNN, which hosted the debate in its studios in Atlanta, Georgia. Veteran journalist Carl Bernstein, who co-authored the Watergate stories that brought down president Richard Nixon in the 1970s, called the event a “horror show”.

Many excuses were made. Biden had had a cold. He sometimes stuttered – but everybody knows he has long had a stutter. His make-up had washed him out. He later said he was jet-lagged (from travel that ended 12 days earlier) and had almost fallen asleep on stage, which did not necessarily help his cause. The family, it was reported, blamed his advisers for not preparing him properly. They wanted the aides fired. But the aides had done a pretty thorough job. They’d not just war-gamed the talking points but had built a mock-up of the CNN debate stage in an aeroplane hangar where they pitted Biden against a stand-in Trump, over and over, for days – an effort, The New York Times reported ahead of the debate, “to position him as a campaign-season fighter who can counterpunch on the fly and combat voters’ concerns about his age”.

People such as Bernstein are now saying it’s obvious there’s been something wrong with the president for some time. Key party donors have rallied for Biden to stand down. Polls suggest most registered voters think Biden no longer has the wherewithal to be president. In fact, many people are openly wondering whether Biden, the oldest president in US history, vying for a second term that would end in his 86th year – and which necessitates travelling everywhere with the keys to nuclear destruction – is still cognitively fit for office.

But is it ever OK to factor somebody’s age into their job? Why are some people still going strong in their 80s and 90s while others struggle? Is Biden too time-worn to be president?

How old are world leaders?

Nebuchadnezzar II, the bejewelled king of the neo-Babylonian empire who ascended to the throne in 605BC and was celebrated for rebuilding the ancient capital of Babylon, ruled for 37 years until his death at 80. Louis XIV, born in a chateau west of Paris in 1638, made it to 76, dying of gangrene after a reign that lasted a record 72 years. Elizabeth II (the second-longest monarch) was 96 when her reign ended upon her death. Tonga’s George Tupou died on the throne in 1893 at 95.

Political leaders, though, are much less likely than kings or queens to stick around into their dotage. Australia’s oldest member of parliament, Bob Katter, is 79, well above average for an MP, which, since Federation, has ranged between 47 and 52. Australian prime ministers average 52 when first taking office, with John McEwen still the oldest at a youthful 67. Our oldest-serving prime minister, Robert Menzies, left office one month and six days after his 71st birthday, in 1966. Former PM Billy Hughes was still an MP when he died at 90 in 1952.

Most global leaders are aged in their 50s and 60s, according to the Pew Research Centre, a Washington think tank, which puts Biden right out there on the X-axis as ninth-oldest leader of 187 United Nations member states surveyed. Only one country has a leader in their 90s: Cameroon, whose 91-year-old president/dictator Paul Biya is, according to Voice of America, being urged by “supporters” to run yet again in the West African nation’s elections in 2025. Iran’s Supreme Leader, Ali Khamenei, is 85.

North Korean dictator Kim Il-sung made it to 82 but his son and successor Kim Jong-il only saw 70 (his son, Kim Jong Un, is 40). Russian leaders tend to cling on for dear life: Leonid Brezhnev’s rule ended after his death by heart attack at 75; mass-murderer “Uncle Joe” Stalin had a fatal stroke at 74; today, the horse-riding wannabe he-man Vladimir Putin is 71 and showing little interest in stepping aside.

‘I will not make age an issue of this campaign. I am not going to exploit, for political purposes, my opponent’s youth and inexperience.’

Ronald Reagan, 1984

US presidents are typically much younger than their Russian counterparts. John F. Kennedy was sworn in at 43, Bill Clinton at 46. Ronald Reagan is currently the record holder for the oldest president at the end of their last term, at 77, though a re-elected (or defeated) Joe Biden will eclipse him, as would Donald Trump, now 78. At 73, Reagan was facing off for re-election against 56-year-old Democrat Walter Mondale when he famously flipped the “age and competency” script during a 1984 presidential debate. “I will not make age an issue of this campaign,” Reagan said. “I am not going to exploit, for political purposes, my opponent’s youth and inexperience.”

On average, business leaders are trending older, in line with a general increase in population age across most of the world. Nonagenarian outliers include investment group Berkshire Hath­away’s War­ren Buf­fett at 93; Rupert Murdoch, also 93, who was executive chairman of News Corp until last year; and Japan’s Nobutsugu Shimizu, who retired from leading the company he founded, Life Corp, in 2021 aged 95.

In the United States, the ages of chief exec­ut­ives have been stead­ily rising for more than a dec­ade, reaching 57 in 2021, according to the Financial Times. While the sample size it used was small, its data “sug­gest that boards – where age is also rising – will con­tinue to favour the vir­tues of exper­i­ence over youth”.

Ita Buttrose, 82, who stepped down as chair of the ABC in March, believes being a leader in her 80s simply meant she knew more. “You learn to understand people better,” she tells us. “You understand them in your earlier years, but I understand them so much better now. You’ve experienced many of the challenges that younger workers are experiencing today. You can speak from your own experience; but not in a know-all way.”

Nobel Prize-winning immunologist Peter Doherty, 83, was thrust back into work six days a week during the COVID-19 pandemic when his expertise was required: “I was flat out.” In politics, though, Doherty believes people should aim to be out of public office by 70 — or 75 at the latest. “They may be capable but I don’t think they should do it. I started backing off in a pretty big way from running things, I think, about 70,” he says. “[Leaders] should be as intellectually active as they want, they should say what they want, they can write books if they want, but they should give up power … many American universities, for instance, will insist that people give up administrative responsibility by age 70.” In Australia, federal judges must retire at 70, although in 2018, NSW raised the retirement age for its judges from 72 to 75.

Neurologist Geoffrey Donnan, 77, stood aside as the director of The Florey Institute of Neuroscience and Mental Health in Melbourne when he was 70, believing “no one should be running a research institute over 70”. He now co-leads an organisation developing lightweight scanners to treat stroke patients and is often the treating doctor on Melbourne’s fast-response mobile stroke unit. “That keeps me young,” he says. “I’ve always loved the adrenaline of helping people in that hyper-acute phase when they first present. You really have to be on your toes and you have to make split-second decisions about what to do.”

How is age a factor in leadership?

Our cognitive processing ability – such as speed of recall, ability to learn, ability to calculate, perception and information processing power – peaks sometime around the age of 20. Mathematicians, physicists and concert pianists often burn brightest in their youth. So why don’t we choose leaders as young as, say, enviromental campaigner Greta Thunberg, who just turned 21?

Some places do, or almost. In 2019, Finland’s Sanna Marin became the world’s youngest serving prime minister at 34. And while not, technically, a world leader (since he defers to the president, 46-year-old Emmanuel Macron, on global affairs) Gabriel Attal, France’s prime minister, is 35 while the current leading aspirant for his job, Jordan Bardella, is 28.

But while voters recognise that raw smarts are useful in leaders, they also value skills, training, knowledge and life lessons, all of which take time to accumulate. Biden has been in politics for more than 50 years, elected to a district council in 1971 then to the US Senate in 1973 when he was 29. Much of his appeal today, though, lies in his humanity, says historian Emma Shortis, senior researcher in the International and Security Affairs Program at the Australia Institute. Biden’s first wife, Neilia, and 13-month-old daughter, Naomi, died in a car crash in 1972. “He was touched by grief.”

As experience accumulates, it can compensate for some of the raw brain power we tend to lose over time, and even temporarily outweigh it. What’s sometimes called crystalline, or crystallised, intelligence – acquired knowledge – provides a shortcut for real-time problem-solving. “During life, we’re given all sorts of problems to deal with, and when we have these problems, we learn a strategy to deal with them,” says Leon Flicker, professor of geriatric medicine at the University of Western Australia. “And not surprisingly, when you’re presented with a similar problem later on, you use the strategy that you’ve already developed previously. It’s the way that we, older people such as myself, convince younger people we’re still up to it – we’re still capable of doing our jobs because we seem so quick because we’ve done something very similar to that previously.”

Indeed, Professor Henry Brodaty at the Centre for Healthy Brain Ageing at UNSW, who is 77, tells us: “If you’ve got a president who gathers a good group of people around him, not an echo chamber, and is able to synthesise all the information and think about it, not be rushed, they may be able to make better decisions because they’ve got that experience and that wisdom.”

A wise man is described in the epic Hindu tale, the Mahabharata: “He is not bothered by mockery. He is not taken in by flattery. Whatever he has studied, he conveys boldly, fearing none. The wise man is not arrogant on account of his learning.” The Financial Times offered a more pragmatic definition in 2008, writing about John McCain, 71, competing against Barack Obama, 47, in that year’s presidential election. “When that 3am call comes, advan­cing years may mean you fumble as you pick up the receiver and it may take you a few seconds to remem­ber where you are, but per­haps you have a more sensible idea what to do next.”

And yet. If old age brings wisdom, at least to some, in leaders it must surely be weighed against the costs that ageing can bring. “My stepmother is over 100 and is sharp as a tack,” says neurologist Geoffrey Donnan, “yet someone else at 65 is starting to drop off a bit ... I think, firstly, it’s up to the individual to have the insight, to recognise that the cognitive abilities are declining. Secondly, perhaps even say to their colleagues, ‘Do you think I’m still performing at an adequate level?’ And be humble enough to do that.”

Putting aside illnesses such as dementia, our personality tends to change as we age. “We know that with older age CEOs, they become more risk-averse, less likely to change the organisation,” says Pitòsh Heyden, Professor of Strategy and International Business at Monash Business School. “That is not necessarily good or bad. There are situations when these are sensible strategic choices.”

A survey of studies on ageing and leadership concludes that with advancing age, leaders become less charismatic and tend to “engage in more inactive or passive types of leadership behaviour than younger leaders” – they don’t get as much done. Another, led by Michael Horowitz from the University of Pennsylvania in 2005, examined interactions between global leaders between 1875 and 2002 and found that older leaders were more likely to initiate and intensify military conflicts than their younger peers.

They are also more prone to frailty – being weak, delicate and at risk of falls and hospital admission. This is not only a possible indication of mental decline and a risk to overall wellbeing but, in a public figure, also an image problem. “Anyone can see that Biden is looking more frail, everyone talks about his stumbling on words and forgetting things,” says Brodaty. “That may be an indication of cognitive decline, but he may still have wisdom ... So the concern is, when people do start declining, it’s very likely it will be progressive. What I think a lot of people are worried about is not necessarily today, but next year or four years from now.”

Prejudices about age endure, even among leaders themselves, observe Joshua Byun and Austin Carson in International Studies Quarterly. “A leader who betrays indicators of ‘senility’ during face-to-face encounters will elicit harsh judgments.” Critically, they write, “perceptions of age shape how observers understand a leader’s agency and shape decisions to ‘engage’ or ‘bypass’ the leader in the context of interstate co-operation”.

A strong memory is not as important as it used to be in a leadership role, says Leon Flicker. “We have ways of supporting our memory.” Instead, “executive functioning” is essential. “Making fine judgment calls, the ability to bring information together and make a judgment about the ideal path. Being able to switch your brain from one way of thinking about things to another, having that sort of mental flexibility, particularly when you’re dealing with problems that don’t have easy solutions. Being able to identify the evidence and judge it for its worth and then critically evaluate it.”

Coherence, competence, composure, reason and skills of communication and articulation are the essential criteria, suggests Steve Lopez in the LA Times. The Australia Institute’s Emma Shortis says an effective president must be able to both successfully navigate the political landscape and communicate competently with the nation. “The most successful and most revered presidents in American history had a combination of those.”

What happens next with Joe Biden?

Age is a delicate topic but not completely out of bounds in US politics. Americans had asked questions about Ronald Reagan in 1980 when he was 69, and again in 1984, and of John McCain in 2008, when he was 71 – both way younger than Trump, 78, and Biden, 81. Commentators also wondered about a clearly frail and debilitated senator Dianne Feinstein, who died aged 90 while still in office in 2023.

Senate minority leader Mitch McConnell is 82 and has suffered several high-profile episodes of freezing on the spot, which he has blamed on lightheadedness from an earlier fall. Current Representative and former speaker Nancy Pelosi, meanwhile, “remains mentally sharp in interviews and maintains a busy schedule” at 84, according to the Washington Examiner. “I think it’s a legitimate question to say, is this an episode, or is this a condition?” she said of Biden in an interview with MSNBC, after the recent TV debate. “And so when people ask that question, it’s completely legitimate — of both candidates.”

Questions around Biden have, until now, at least, been couched in a roundabout way, says Shortis, who focuses on US and global environmental politics. “Age, I think, has been a factor for a long time,” she says. “The presidency ages everybody. You just have to look at Obama from his inauguration through to the end of his second term. It’s an incredibly hard job. But, you know, the reality around Biden and his age, I think, is just inescapable. I think what happened at the debate was that it just became undeniable that his performance was so bad that it couldn’t be turned away from any more.”

‘I didn’t have a good debate. That’s 90 minutes on stage. Look at what I’ve done in 3.5 years.’

President Joe Biden, 2024

Alan Cadman was one of Australia’s longest serving members of parliament, retiring at 70 in 2007 after more than 33 years of representing the Liberal Party. He watched Biden’s debate performance and concludes: “I’ve not seen a single person [in politics], no matter what age or incapacity, so poorly presented as he is at the moment.” Cadman observes: “He was stalled and stopped on a number of occasions. He didn’t know where to go. He mixed up his subjects. He was confused, there’s no doubt about it.”

In the days that followed the Camp David family huddle, Biden sought to assuage doubt, even as polls showed him slipping behind Trump. “No one’s pushing me out,” he reportedly told campaign staff in a call. “I’m not leaving.” He said he had been medically examined and found fit but was going to limit engagements after 8pm. “I had a bad night,” he told The Earl Ingram Show of the debate debacle. “And the fact of the matter is, I screwed up, I made a mistake. But I learned, from my father, when you get knocked down you get back up ... I didn’t have a good debate. That’s 90 minutes on stage. Look at what I’ve done in 3.5 years.”

Practically, if the Democrats wanted to replace Biden, they would need to persuade him to drop out of the race. He can’t be fired at this stage of the electoral cycle, already his party’s “presumptive nominee”, having collected a vast majority of pledged delegates in the primaries campaign earlier this year. These delegates could, technically, change their mind: they are obliged to support him only by “good conscience”, according to the party’s rules. But that would be highly irregular, according to AP: “It would be unprecedented for delegates on a wide scale to support a candidate other than the one they were pledged to support.”

Indeed, writes Charles M. Blow in The New York Times: “The inertia of a presidential campaign is one of the most powerful forces in politics. Ending one after a party’s nomination has been secured is almost unfathomable. The candidate is already strapped to the rocket.”

Even if Biden was to step aside, or somehow be removed, it could prove deeply destabilising for his party this close to the Democratic National Convention on August 19, and the presidential election on November 5. The Democrat delegates pledged to support Biden at the convention would be freed to choose another leader; but as Biden ran his primary campaign virtually uncontested, there is no obvious replacement waiting in the wings. The easiest path would be for Vice President Kamala Harris to take the reins.

The Constitution allows for a president who is “unable to discharge the powers and duties of his office” to have the vice president “immediately assume the powers and duties of the office as acting president”. Failing that, writes Harvard Law School professor Jeannie Suk Gersen in The New Yorker, “the vice president and a majority of the cabinet can declare that Biden is unable to discharge the powers and duties of his office, whereupon Harris would become the acting president. At that point, Biden could say that ‘no inability exists’ and resume his office, but I can’t imagine that he would do so after his vice president and cabinet have taken such a step.”

Harris is polling better than Biden, “within striking distance of Trump in a hypothetical match-up”, according to CNN, partly because of broader support from women. Harris would go to the convention with Biden’s blessing, where she would likely inherit many of the delegates pledged to him. She would also inherit the Biden ticket’s campaign war chest.

What are the chances of Biden stepping aside? It is extremely rare for a sitting president to not stand for a second term. It happened most recently in 1968 when Lyndon Johnson, losing the war in Vietnam and battered by racial disharmony at home, made a shock televised address in which he declared: “I shall not seek, and I will not accept, the nomination of my party for another term as your president.”

While he had been unlikely to win, his decision still plunged his party into disarray. The Democratic National Convention was chaotic, with scuffles among delegates, and police clashing with anti-Vietnam War protesters outside. Eventually, Hubert Humphrey was chosen as the party’s presidential candidate and went on to lose the presidential election to Nixon.

“It’s easy to think they will switch leaders, but that would be a seismic decision by the Democratic Party to do that,” says Shortis. “We can’t underestimate the fear of an open or a contested convention. They’re terrified of that happening. So it’s entirely possible that they will just kick a can down the road and fight among themselves for months and end up making the situation worse.”

Ultimately, says Ita Buttrose: “If I was the president of what used to be the most powerful country in the world – but slowly losing that position – why would you want to give it up? Power is a very powerful aphrodisiac.” She adds: “Sometimes, you have to put the job ahead of your own concerns. There’s a point where you think, should I step aside for the good of the organisation? It’s the hardest, toughest leadership decision of all. But you have to make it because people depend on you to make the right decision.”

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