World leaders from Margaret Thatcher to Donald Trump have famously got by on just four or five hours of sleep a night.
But science now shows someone with their finger on the nuclear red button should really be getting a few more hours in bed.
Missing out on sleep causes people to take riskier decisions, a study has found, and can change them from a risk-averse to a risk-taking person.
In a finding described as ‘alarming’ by the researchers, people whose sleep is cut back to five hours a night – such as Donald Trump – could risks without realising they are doing so
In a finding described as ‘alarming’ by the researchers, people whose sleep is cut back to five hours a night take these risks without realising they are doing so.
Asked if they are behaving more recklessly than usual or taking more chances, they say they are not.
The results emerged from a study of 14 men in a financial game, in which they gambled for a cash sum.
However the authors say the results also relate to politicians, bankers and business leaders – and may even help to explain the global financial crash of 2008.
Co-author Christian Baumann, professor of neurology at the University of Zurich, said: ‘To some extent, these findings are frightening. There are people who can call themselves short-sleepers and keep their risky behaviour to a minimum but most of us increase our risk-taking when sleep-deprived.
‘We know Donald Trump sleeps for four or five hours a night, which these results suggest is concerning.
‘Politicians who take decisions of great importance for the world, and business leaders who think missing out on sleep makes them more productive, should take note.’
A lack of sleep is known to cause unease, dissatisfaction with life and a lack of motivation, but there have been few studies on risk-taking behaviour.
Researchers recruited 14 men aged 18 to 28 and subjected them to just five hours of sleep a night, while asking them to play a gambling game.
The participants could accept an automatic payment of 20 Swiss Francs (£16) or gamble for up to 100 Swiss Francs (£81).
World leaders such as Margaret Thatcher (pictured) have famously got by on just four or five hours of sleep a night. The study suggests the rise in dangerous behaviour is because of changes in the brain caused by a lack of sleep
The riskier their decision, the higher the possible prize in the game, although the study group could also end up with nothing.
As the week went on, 11 of the 14 men began to behave more riskily than previously, while six people who had been risk-averse changed their behaviour to become risk-seeking.
But when questioned how riskily they behaved over the week, the participants did not think their actions had changed.
The study suggests the rise in dangerous behaviour is because of changes in the brain caused by a lack of sleep.
Science now shows someone with their finger on the nuclear red button should really be getting a few more hours in bed (stock image)
The authors, who took brain scans during the tasks, found slow sleep waves were reduced in the right prefrontal cortex, which previous studies show is linked to higher risk-seeking behaviour.
‘We assume that behavioural changes occur for anatomical-functional reasons to some extent as a result of the right prefrontal cortex not being able to recover properly due to a chronic lack of sleep,’ Professor Baumann said.
Around 30 per cent of us do not get enough sleep and the study, published in the journal Annals of Neurology, ends with a warning.
It states: ‘While we cannot exclude that individuals in positions that require high-impact decision-making may be more resilient to the effects of sleep restriction, our results suggest that all of us, but particularly leaders of companies and countries, are well advised to work and make decisions only when fully sleep-satiated.’