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Under these pseudoprimitive conditions, then, sleep was preceded, punctuated and terminated by long periods of quiet restfulness. This pattern of sleeping in two distinct blocks of time is known as biphasic sleep. It is typical of many mammals living in the wild and was probably the natural sleep pattern of our ancestors. We all retain the biological capacity for biphasic sleep, despite the profound changes in humanity’s environment since the advent of artificial lighting and the 24-hour society. A group of thoroughly modern Americans reverted to biphasic sleep within days of being given the opportunity. The nearest contemporary equivalent is the afternoon sleep of the siesta, a custom that still survives in some countries.
The predominant lifestyles of artificially-lit industrialised societies have led us to compress our sleep into a single block of seven or eight hours, as though we were living permanently in midsummer (but usually without the siesta). We have jettisoned the additional hours of quiet rest and the seasonal variations that once accompanied human sleep. We have also lost the main channel that once existed to our dreams. During the 14-hour nights, as they alternated between sleep and quiet rest, Wehr’s volunteers usually awoke from dreaming, giving them ample opportunity to lie quietly in the dark and contemplate their dreams. In later chapters we shall consider why dreaming evolved and what it does for us.
A quite different reason for believing that many people nowadays are chronically sleep-deprived is the mass of evidence that sleepiness is a major cause of accidental injuries and deaths. We shall now look at how sleepiness jeopardises safety-critical activities such as driving a car, flying an aeroplane, being a doctor, running a country and operating a nuclear power plant.
Sleepy drivers (#ulink_46e0c30e-4abe-5fe4-b6e1-a242f0727cef)
Till o’er their brows death-counterfeiting sleep
With leaden legs and batty wings doth creep.
William Shakespeare, A Midsummer Night’s Dream (1595–6)
Accidents are one of the leading causes of death in developed nations, and sleepy people are responsible for many of them. A remarkably large proportion of vehicle accidents are the direct or indirect result of tired drivers losing concentration or falling asleep at the wheel. A few examples may give a flavour of the carnage they cause. In March 1994 near Barstow in California, a pickup truck carrying 20 people veered off the road and crashed into a culvert after the driver apparently fell asleep at the wheel. The driver survived but 12 passengers died. In July 1995 near Roquemaure in France the driver of a bus carrying Spanish students from Amsterdam to Barcelona seemed to nod off then wake abruptly as his bus scraped a passing truck. He lost control and the bus swerved wildly before rolling over several times. The accident caused 22 deaths and 32 injuries. In February 2001 a sleep-deprived driver caused the Selby rail disaster in the UK, after he fell asleep at the wheel and his vehicle crashed onto a railway line. Ten train passengers died. The driver, Gary Hart, admitted getting no sleep the night before the crash, but claimed he could still drive safely. He was sent to prison.
Scientists have judged that sleepiness is a factor in at least 10 per cent of fatal car crashes in the USA and more than 50 per cent of fatal crashes in which a truck driver is killed. A 1994 report by the US National Commission on Sleep Disorders concluded that driver fatigue contributed to 54 per cent of all vehicle accidents in the USA. A comparable situation applies in the UK and elsewhere. Research concluded that at least 10 per cent of vehicle accidents in the UK are related to sleepiness, though some experts have put the figure much higher. Two large surveys in England found that sleepiness was a causal factor in 16 per cent of accidents to which the police were summoned and at least 20 per cent of accidents on motorways. Driving on a motorway is generally more monotonous than driving on a minor road, and monotony heightens the risk that a tired driver will fall asleep at the wheel. Half the drivers involved in these sleep-related accidents were men under the age of 30 and many of the accidents involved truck drivers, company cars or workers returning home from night shifts.
For every sleepy driver who actually crashes there are uncounted numbers who have had near misses. A large survey by the British Transport Research Laboratory found that 29 per cent of drivers had come close to falling asleep at the wheel within the previous year, while other research established that at least 5 per cent of middle-aged male drivers had actually fallen asleep while driving on several occasions. Not surprisingly, drivers suffering from moderate or severe daytime sleepiness are at least twice as likely to have a vehicle accident.
The official statistics tend to underestimate the true extent of the sleepiness problem, and it is easy to see why. Drivers who survive crashes are naturally reluctant to admit that they dozed off at the wheel, even if they recollect doing it. And it is difficult to prove legally that sleepiness caused a crash (especially if the driver is dead). Unlike alcohol, drugs or mechanical defects in a vehicle, sleepiness leaves few evidential traces. You can easily measure how drunk someone is at the roadside immediately after an accident. But measuring sleepiness is neither quick nor easy, and in practice it is simply not done.
The systematic under-reporting of fatigue was highlighted by accident statistics for Italian highways. Over the period from 1993 to 1997 the Italian authorities officially ascribed the cause as sleep in only 3 per cent of accidents. However, by analysing the data in more depth, researchers were able to estimate that sleepiness had probably contributed to about 22 per cent of accidents. If true, this means that the official statistics had underestimated the hazard of driver sleepiness by a factor of seven.
The time of day is a major element in the relationship between sleepiness and accidents. Thanks to our natural circadian rhythms, we all feel sleepier at certain times in the 24-hour cycle (usually in the early hours of the morning and again in the afternoon) regardless of how much sleep we have had. As expected, sleepiness-related vehicle accidents occur most often in the early hours of the morning and in the afternoon, during these natural peaks in sleepiness. Older drivers are particularly susceptible to afternoon sleepiness, whereas younger drivers are more prone to crashing late at night or in the early hours. When researchers analysed the data for accidents in which the driver had been injured or killed (excluding those involving alcohol) they found that young drivers were between five and ten times more likely to crash late at night than during the morning.
Driving late at night poses a risk for train drivers as well. In one study, scientists monitored train drivers while they drove the same route, both by day and at night. The train drivers felt much sleepier when driving at night, and physiological measurements mirrored their subjective feelings. Their brain waves, heart rates and eye movements at night were all characteristic of sleepy people. Four of the 11 drivers who were monitored admitted to dozing off during the night journey and two of them failed to respond to signals. Sleepiness has almost certainly caused numerous rail crashes over the years, but again the official statistics have systematically underestimated its importance.
The sleepiness experienced by many drivers is partly a product of natural cìrcadian variations in wakefulness. But much of the blame rests with simple lack of sleep. And when lack of sleep is combined with driving at odd hours, the effect can be lethal. Prevailing social attitudes towards this issue are frankly perverse. Many parents think nothing of packing their family into a car and then driving long distances to a holiday destination while they are seriously tired. They would be horrified at the thought of doing this while drunk, but the effects of tiredness and alcohol on their ability to drive safely are strikingly similar, as we shall see in the next chapter. The number of drivers involved is large. In August 1996 French researchers assessed the extent of sleep deprivation among drivers during the holiday season, by randomly stopping two thousand cars at tollbooths and interviewing the drivers. It transpired that half of them had slept less than they would normally have done during the previous 24 hours. On average, these happy holidaymaking drivers had slept for 3.4 hours less than normal.
Many long-haul truck drivers get insufficient sleep, with potentially serious consequences for their performance and safety. When investigators studied truck drivers working in the USA and Canada they found that the drivers spent on average slightly more than five hours a day in bed and got slightly less than five hours’ sleep. This was much less than their self-reported ideal of more than seven hours a day. Nearly half the truck drivers augmented their sleep by napping, but the naps were not sufficient to compensate. Video and EEG brainwave recordings revealed that more than half the drivers had at least one period of drowsiness while they were driving, and two actually fell asleep at the wheel.
Even changing the clocks can be dangerous. The switch to daylight-saving time each spring reduces the length of one night by one hour, which slightly disrupts sleep routines for the next few nights. The extra sleepiness caused by even this apparently trivial disturbance is enough to generate a statistically significant seasonal rise in traffic accidents. Fatal accidents peak on the day immediately following the changeover. Alcohol-related accidents also rise during the week after the clocks change, probably because the effects of alcohol and sleepiness reinforce each other.
You might think that changing clocks in the opposite direction each autumn would have the reverse effect, but you would be wrong. When researchers analysed 21 years of US vehicle accident statistics, they found that the switch back from daylight-saving time each autumn was also accompanied by an increase in fatal accidents – despite the fact that in this case everyone got an extra hour in bed. The likely explanation is that many people anticipated the extra hour in bed by staying up even later the night before. This was borne out by the fact that the rise in fatal accidents around the autumn changeover was most marked just before the clocks changed, and especially in the early hours of the morning.
One of the most alarming aspects of daytime sleepiness is that we can fall asleep briefly without even noticing. You are unlikely to be aware that you have slept unless your sleep has lasted for at least a couple of minutes. Tired people can therefore fall asleep at the wheel of a speeding vehicle for tens of seconds at a time and never even know. Researchers measured this phenomenon by waking volunteers after daytime naps of varying durations and asking them if they had been asleep. (Their sleep was confirmed by objective physiological measures.) After one minute of sleep only 15 per cent of subjects had any awareness that they had been asleep, and only 35 per cent were aware even after five minutes of sleep. The upshot is that so-called microsleeps, lasting anything up to a minute, often go unnoticed. Suppose a sleepy driver lapses into a microsleep for only ten seconds while driving on a motorway at 70 miles an hour. During that brief, unnoticed lapse in waking consciousness the vehicle will cover about 70 car lengths. It is virtually certain that while you are reading these words someone, somewhere is microsleeping at the wheel of a speeding vehicle.
One apparent obstacle to prosecuting drivers who fall asleep at the wheel is proving that they were aware of their dangerous state and are therefore legally responsible for their actions. No one could reasonably claim to have been completely unaware that they were dangerously drunk, but a driver might conceivably claim to have been oblivious of being sleepy before crashing. However, the experimental evidence suggests otherwise. Sleep does not occur spontaneously without prior warning in the form of sleepiness.
Drivers who fall asleep at the wheel may not recall the actual moment of falling asleep, but they will almost certainly remember feeling sleepy beforehand. Scientists established this by monitoring sleep-deprived volunteers while they drove a simulator. The sleepier the drivers felt, the more mistakes they made. Serious errors, of the type that might have caused a crash in real life, were always preceded by prolonged feelings of sleepiness. By the time an ‘accident’ took place the tired driver had invariably been consciously fighting sleepiness for some time. The strong implication is that drivers who fall asleep at the wheel in real life will almost certainly have felt noticeably sleepy beforehand. The problem is that so many sleepy drivers press on regardless, fighting their sleepiness and risking lives. Many drivers harbour the illusion that they will not fall asleep at the wheel provided they fight hard enough. What they fail to appreciate is that if you are sufficiently sleepy you will eventually fall asleep, no matter how hard you resist.
Not all sleepy drivers are sleepy because of sleep-deprived lifestyles. Some are sleepy because they have a medical sleep disorder, often undiagnosed. The most common of these, called sleep apnoea, involves the repeated interruption of breathing during sleep. We shall be taking a closer look at sleep apnoea in chapter 15. Individuals who suffer from this disorder can become severely sleep-deprived, although they rarely know why. The daytime sleepiness caused by the repeated disruption of their sleep every night can severely impair their driving performance.
Sleepy drivers not only have more accidents, they also have worse accidents. The hallmark of an accident caused by a driver falling asleep at the wheel is the absence of skidmarks. Of all the crashes that are attributed to drivers falling asleep, more than three quarters involve the car driving off the road and more than half involve high speeds.
Car and truck manufacturers have done little to tackle the safety hazard created by sleepy drivers. Driver fatigue remains one of the biggest weak spots in vehicle safety, perhaps because it is much easier to modify the design of a vehicle than to modify the behaviour of humans. However, some promising technology is being developed that may show the way. One system uses cameras mounted in the dashboard to track the driver’s eye movements. It exploits the fact that people blink in a characteristic way when they are about to fall asleep. The device warns the driver if the blink frequency indicates a risk of nodding off at the wheel. IBM is developing an even more sophisticated system, known as the Artificial Passenger. An intelligent computer, which knows the driver’s personal profile and interests, holds a conversation with the driver. It asks questions and even tells jokes (though humour is reportedly not yet one of its strengths). If the driver’s responses are slow, flat in intonation and fail to make sense, the Artificial Passenger may judge that the driver is sleepy and urgently needs to be revived. If so, it will automatically open one of the car’s windows, sound an alarm or even activate a device that sprays cold water in the dozing driver’s face.
Governments are only just beginning to wake up to the carnage caused on our roads by sleepiness, having focused for so long on the dangers of alcohol. And yet sleepiness accounts for far more road deaths than alcohol, let alone drugs.
Sleepy pilots (#ulink_dc39c136-f720-5caf-bff8-d732597e2a37)
My spirits grow dull, and fain I would beguile
The tedious day with sleep.
William Shakespeare, Hamlet (1601)
Fatigue and chronic sleep deprivation are obviously of crucial relevance to aviation safety. Tired pilots are bad pilots, for all the reasons that tired drivers are bad drivers. How big is the problem in practice?
Historically, severe fatigue among aircrews has sometimes been a major problem during crises where huge demands have been placed on precious personnel. Take, for example, the Berlin airlift of 1948–9. In June 1948 the forces of the former Soviet Union occupying eastern Germany began a blockade of road, rail and other communications between Berlin and the West. An international crisis ensued. The USA and UK mounted a huge airlift operation to supply West Berlin with food and other essential supplies. The airlift continued for 11 months until the Soviets eventually withdrew their blockade. During that time Allied planes delivered more than two million tons of food, fuel and other supplies to the beleaguered residents of West Berlin. To sustain this huge effort, the aircrews worked punishing schedules with grossly inadequate sleep. There were many accidents, some of them the result of fatigue. A special investigation during the crisis led to immediate improvements in the aircrews’ working conditions and sleeping quarters, which probably made a material contribution to the ultimate success of the whole operation.
Even in peacetime, tiredness is not unknown on the flight deck. Most airline flight crews experience some sleepiness and impairment in their performance, especially during long-haul and overnight flights. In one recent study, scientists from the British Defence Evaluation and Research Agency monitored 12 airline pilots during routine nine-hour flights between London and Miami. Recordings of their EEG brain-wave activity and eye movements revealed that 10 of the 12 pilots either slept or displayed signs of significant sleepiness during the flights. These episodes were often brief, lasting less than 20 seconds. Microsleeps of this brevity generally go unnoticed, and the pilots would probably have been unaware of drifting off.
Scientists from the NASA Ames Research Center in California also detected fatigue among flight crews on commercial long-haul flights. The crews on these flights, which crossed up to eight time zones, became measurably sleep-deprived. They felt more fatigued than normal, consumed more caffeine, ate more snacks and reported more minor health problems such as headaches, nasal congestion and back pain. Their sleep loss was made worse by the fact that their circadian rhythms did not have time to synchronise with local times. Their natural low points in alertness therefore often occurred while they were on duty, amplifying their sleepiness.
Jet lag is not just unpleasant and stressful – it also has physical effects on the brain. Researchers compared two groups of female flight attendants who had all been working on long-haul flights for at least five years. Half the women were in jobs that allowed them two weeks to recover between long-distance flights, while the other half usually had only a few days’ rest in between. The women who had little time between flights performed significantly worse on tests of learning and memory; their reactions were slower and they made more mistakes. More significantly, brain scans revealed distinct physical changes in their brains. A region of the brain known as the right temporal lobe had shrunk significantly. The women with the most shrunken right temporal lobes also had the highest levels of cortisol, a stress hormone that is known to affect the structure of the brain and the functioning of the immune system.
The implication of this research is that people who regularly fly long distances, crossing more than six or seven time zones, should ideally allow at least ten days to recover before doing it again. The research also raises questions about the policies of airlines that require their flight crews to fly long haul without adequate rest periods in between. The thought of sleepy, jet-lagged pilots with wizened right temporal lobes and impaired mental abilities slumped behind the controls of jumbo jets is mildly alarming.
Flying for a living can be tiring even when it does not involve crossing multiple time zones and becoming jet-lagged. Like workers in many other industries, flight crew are often required to start work early in the morning, and this alone can starve them of sleep. Researchers who monitored the sleep of female cabin crew found that when the women worked early mornings their sleep was reduced to an average of just over five hours. This is not enough sleep for the vast majority of people. Early-morning working was also unpleasant and mildly stressful for these women. They reported feeling apprehensive about having to rise early, they felt sleepy during the day and they complained more about their sleep being unrefreshing.
The only cure in situations like these is getting enough sleep, and at the right time of day. But that is not always possible on long-haul flights. Napping can provide a short-term palliative. If all else fails, a British firm has patented a technological aid to keep airline pilots awake. Worn like a wristwatch, it uses a motion sensor to monitor the pilot’s movements. A loud alarm sounds if there has been no movement for a few minutes. Personally, I would prefer not to find myself on a plane flown by a pilot who needs one of these devices. But if I do, I hope it works.
Space flight is even less conducive to sleep than air travel. Astronauts can and do sleep in space, but not very well. Space flight confuses the body’s internal clock and reduces both the quantity and quality of sleep. Astronauts on the Space Shuttle were typically getting only five or six hours of poor quality sleep a night, and often resorted to sleeping pills. More than 40 per cent of Space Shuttle astronauts took medication for sleep disturbances – about the same proportion as took drugs for motion sickness.
In recent years, NASA has been giving its astronauts doses of the ‘sleep hormone’ melatonin to help them sleep. (We shall see what melatonin does in chapter 6.) However, research by Charles Czeisler at Harvard Medical School found that melatonin actually had little beneficial effect on astronauts’ sleep. What did work, however, was covering the astronauts in electrodes to monitor their sleep. Czeisler discovered that Space Shuttle astronauts slept better when they were festooned with electrodes and physiological monitoring equipment. The most likely explanation is simple and psychological. The astronauts had probably been sleeping badly because they were so focused on performing their many duties. Swathing them in sleep-monitoring electrodes convinced them that sleep was also a legitimate and important part of their duties, and they consequently relaxed and slept better despite the marginal discomfort.
Sleepy doctors (#ulink_4696b113-aab3-5fcc-b50a-d8a6f9cdbc08)
Think not, is my eleventh commandment; and sleep when you can, is my twelfth.
Herman Melville, Moby-Dick (1851)
To find the prime example of skilled professionals who routinely perform demanding, safety-critical tasks while severely sleep-deprived we need look no further than medicine. Chronic sleep deprivation is rife among hospital doctors, who are not superhuman enough to be immune from its consequences. Lack of sleep impairs their mood, judgment, decision making, thinking abilities and communication skills just like anyone else. One commentator recently described medical training in the USA as ‘a gruelling endurance test in which patients are often those most at risk’. The situation in the UK is no better.
Just how tired are doctors? According to the research data, some of them are very tired indeed. A study of American physicians undergoing postgraduate medical training illustrates the problem. During a typical 36-hour period of on-call duty, the interns spent less than five hours in bed and slept for an average of less than four hours. That is not enough. Another American study found that three out of four residents in obstetrics and gynaecology were working between 61 and 100 hours a week, and more than two thirds reported getting less than three hours’ sleep while on night call. Perhaps unsurprisingly, a large majority wanted limits placed on their work hours, despite concerns that this might restrict their professional experience. Much the same is true for doctors in other countries. For instance, house officers in Stockholm hospitals were found to sleep for an average of only four hours when on night call.
Three or four hours’ sleep is not enough for most people. Research has shown that doctors who have slept for less than five hours in the previous 24 display significant deteriorations in their memory, intellectual skills, language and numeracy. Doctors working night shifts get less sleep than those on day duty, and their performance is consequently worse. A study at Stanford University found that emergency physicians slept for an average of 6.3 hours after working day shifts, but only 5.2 hours after night shifts. Their performance and mood suffered accordingly: those working nights had slower reaction times and took one third longer to perform a standard medical procedure. Their performance deteriorated during the course of a night shift and they became progressively more likely to make mistakes. They also felt less alert, less motivated, less happy and less clear-thinking than when they were on day shift. Given the choice, any sane patient would want to be treated by a doctor working day shifts.
As we shall see in the next chapter, sleep deprivation has a big impact on tasks requiring sustained concentration and effort. But tired people are often able to perform simple or engaging tasks in short bursts. Sleep-deprived doctors usually cope surprisingly well with brief but invigorating crises. Problems are more likely to arise with routine, repetitive tasks requiring prolonged attention. It might be relevant that the impact of sleep deprivation is found to vary somewhat between the different medical specialities, with surgeons being the least affected.
We will also see in the next chapter that sleep deprivation erodes our mood, motivation, social skills, communication skills, creativity and lateral thinking. Again, doctors are no exception. Psychologists who assessed junior doctors after a night of dealing with emergency admissions found deteriorations in their mood and motivation, as well as the usual impairment in short-term memory. Sleep-deprived doctors also perform significantly worse on measures of creative thinking and originality. They are less capable of solving complex problems that require originality and non-linear thinking, such as diagnosing an unusual condition.
To put icing on the cake, sleep-deprived doctors have an alarming tendency to fall asleep when driving their cars. An American study of paediatricians found that half of them admitted to having fallen asleep while driving, almost always after a night on duty. The on-call doctors notched up substantially more traffic accidents and traffic citations than their faculty colleagues. Their propensity to fall asleep at the wheel was unsurprising, considering they got less than three hours of sleep during on-call nights. So, after unintentionally jeopardising their patients’ lives while on duty in the hospital, sleep-deprived doctors put themselves and other road users at risk while driving home.
The madness of politicians (#ulink_70d805b8-dea4-5f00-9651-d4c1102fa389)
I have noted as something quite rare the sight of great persons who remain so utterly unmoved when engaged in high enterprises and in affairs of some moment that they do not even cut short their sleep.
Michel de Montaigne, ‘On Sleep’, Essays (1580)
Long hours and inadequate sleep are standard features of political life. Those highly motivated, hardy individuals who survive the fierce competition and reach the top must have an above-average capacity for coping with little sleep. Having got to the top, they then set a bad example to the rest of us by projecting an image of tireless and unceasing industry. To accuse a politician of looking tired is frankly insulting. But they are only human, and inside that aura of sleeplessness there often lurks a tired person who secretly wants to spend more time asleep in their own bed.
Mythology and image-making abound when politics meets sleep. During Margaret Thatcher’s tenure as prime minister an absurd myth was fostered that it is both feasible and admirable for people routinely to sleep for only four hours a night and work hard for the remaining twenty. Hogwash. With the possible exception of a tiny minority of extraordinary individuals, humans simply do not thrive or perform well for long on four hours’ sleep a night.
Negotiators sometimes deliberately exploit the debilitating effects of acute sleep deprivation to achieve their aims. People who have hardly slept for two or three days will agree to almost anything at four o’clock in the morning. Dragging out negotiations over several days may be irksome, but it can work if you make sure your side gets more sleep than the opposition. But more often than not, tiredness just gets in the way of rational politics. In 1997, after a sleep-deprived marathon of negotiation, representatives of 160 nations agreed the Kyoto Protocol, aimed at reducing global emissions of greenhouse gases. Three years later, fatigue helped to set back the environmental cause. In November 2000 an international summit convened in The Hague to thrash out unresolved problems left hanging by the Kyoto treaty. The negotiations ground on for 12 long days, leaving the delegates exhausted. In the early hours of the morning on the final day the British deputy prime minister, John Prescott, proposed a deal that he thought would break the logjam. But the deal collapsed, reportedly because the French delegate refused to make a difficult decision. A furious Prescott laid the blame squarely on the French environment minister. He told journalists: ‘She got cold feet, felt she could not explain it, said she was exhausted and tired and could not understand the detail and then refused to accept it. That is how the deal fell.’ The summit ended without reaching agreement.
The burden of work on the politicians and officials who run our nations has grown inexorably over the years. The number of decisions they must take has mushroomed, as the world has become an ever more complex, law-bound and media-scrutinised place. The insatiable demands of the 24-hour news media add greatly to the load. Political leaders are frequently overloaded, with insufficient time to think and formulate policy, let alone get enough sleep.
Academic observers of the British government scene calculated that between the 1960s and the 1990s the average working day for government ministers grew from 14 hours to 18 hours. The eminent political historian Peter Hennessy described the job of a British cabinet minister as ‘a conveyor belt to exhaustion and underachievement all round’, while a former senior adviser to the prime minister wrote that ‘Ministers are governed by diaries which seem designed to break them in physique or spirit in the shortest possible time.’
The diaries of the late Alan Clark, who served as a government minister in the 1980s and early 1990s, give illuminating glimpses into the sheer grind of ministerial life. Clark observed colleagues who were ‘boss-eyed’ with fatigue after working past midnight. One diary entry from 1984 describes how the civil servants would always find more work for him to do, no matter how little sleep he had had:
Today has been vilely full. Went early to Leicester after a late, late vote and impossible to drowse in the train as officials were watching me beadily in case (their excuse) anything in the brief ‘needed explaining’. I dropped off, as good as, several times during monologues at the various offices.
To add to the hazards of politics, Clark’s life was occasionally jeopardised by an exhausted government driver who had a tendency to nod off while conveying the minister along motorways at antisocial hours. Alan Clark’s experiences were by no means unusual. Geoffrey Howe, who was Foreign Secretary in the 1980s and who, like Alan Clark, worked under the notoriously unsleeping eye of Margaret Thatcher, described his gruelling work regime like this:
During six years at the Foreign Office I took home, to work through overnight while others slept, no less than 24 tonnes of paper … Six o’clock was my normal time for getting up. My average bedtime was about four hours earlier.
The long-hours culture affects not only the elected politicians but also the officials who serve them (and, some would claim, run the country). Sir John Coles, who was head of the British Diplomatic Service from 1994 to 1997, described the problem like this:
Long working hours, pressure and flurry were part of Foreign Office culture. We liked to feel busy and under pressure … But it became necessary to question some of this culture. These things did not necessarily lead to good policy. Tired, pressurised officials were liable to make mistakes.
The demands now are, if anything, even greater. In December 2000 Tony Blair was asked, during an Internet chat forum with members of the public, what he remembered dreaming about on the night after his first general election victory in 1997, and what was the last dream he remembered. The prime minister’s answer was revealing about the punishing lifestyle that goes with his job:
I don’t remember getting much sleep at all that night … After a couple of hours’ sleep, we were up early to prepare for going to Buckingham Palace. As for dreams, I’ve not had much chance for sleep over the past few days, let alone dreams.
Jet lag caused by frequent international travelling adds to the problem. In the immediate aftermath of the terrorist attacks in the USA on September 11, 2001, Tony Blair engaged in a gruelling programme of shuttle diplomacy that saw him travel more than 40,000 miles on 31 international flights in the space of a few weeks. And the fact that he then looked tired made the front pages of the newspapers.
British Members of Parliament work some of the strangest, if not the longest, hours of any legislature in the world. In October 2000 The Times published the results of one of the most detailed surveys ever carried out into MPs’ lifestyles. The survey revealed a nightmarish world of long hours and chronic sleep deprivation. Most MPs said they worked between 71 and 80 hours a week, with one in six working up to 90 hours a week. One government minister logged a working week of 91 hours in Westminster followed by 20 hours at the weekend, leaving an average of eight hours a day for everything else including travelling, family life and a little sleep.
The response from one MP was illustrative. The constituency he represented, and where his family still lived, was a long way from London. He would leave home at five a.m. on a Monday morning and return in the small hours of the following Friday morning. His weekend at home would be spent on constituency business, and then there were the occasional foreign trips with a parliamentary committee. He and his partner planned to go out together on Saturday nights but he was usually so tired by then he would fall asleep. Once, while driving home from London, he had almost fallen asleep at the wheel and crashed. There has been some modernisation of parliamentary schedules, in response to pressure from MPs, but the long-hours culture remains deeply embedded.
Some politicians cope with the long hours with the assistance of drugs of various kinds. In the USA, coke is a favourite – particularly the diet cola variety. During the US presidential election campaign in 2000, candidate Al Gore engaged in an electioneering programme of awesome intensity, involving 19-hour days and an itinerary that criss-crossed the continent. ‘Our campaign consists of a lot of long days and a lot of short nights,’ said Gore’s spokesman. ‘While some candidates may look for their feather pillows, Al Gore is looking for every single undecided voter he can find.’ To help him remain awake and vaguely sentient, Gore reportedly drank copious amounts of Diet Coke. One of his aides was explicit about the reason: ‘These are high-caffeine days. He needs his fuel to get through them.’ Sadly for Gore, the caffeine was not enough.
George W. Bush, who beat Al Gore by the slimmest of slim margins, became notorious during the election campaign for his verbal fluffs and tortured syntax. Whole books have been dedicated to Bush’s gaffes, malapropisms and garbled sentences. One American psychologist even suggested that Bush’s difficulties with the spoken word resulted from a lack of sleep in someone who apparently needed a lot of it.
Perhaps the defeated Al Gore could draw a minuscule crumb of comfort from an informal survey, which was conducted several months after the presidential election and reported to the International Conference for the Study of Dreams in July 2001. This survey found that conservative Republican supporters were nearly three times more likely to experience nightmares than their less conservative Democrat opponents. Half of the dreams recalled by Republicans were nightmares, compared with fewer than one in five of Democrats’ dreams. Moreover, the conservatives’ dreams were generally more frightening and more aggressive in content.
When the next big crisis erupts on the world stage, remember this. The politicians and officials who will be handling that crisis will be getting little sleep, perhaps for days at a time, and they will consequently become even more sleep-deprived than they already were. Their reactions, judgment, rationality, mood, memory, creativity and social skills will deteriorate, and they will become more prone to taking inappropriate risks. You might conclude that the world would be a safer and saner place if our leaders and their officials spent more time in bed (asleep).
Truly, madly, sleepily (#ulink_066d4b93-ca47-5819-88e3-8f715972c0e7)
I have an exposition of sleep come upon me.
William Shakespeare, A Midsummer Night’s Dream (1595–6)
The human errors caused by tiredness sometimes have truly catastrophic consequences, and there have been plenty of man-made disasters to prove it.
Tiredness lay behind the environmental disaster that occurred when the supertanker Exxon Valdez ran aground in Prince William Sound, Alaska, spilling 11 million gallons of crude oil into the pristine waters and polluting thousands of miles of shoreline. The official investigation by the US National Transportation Safety Board concluded that sleep deprivation was a direct cause. The accident took place just after midnight on 24 March 1989, when the Exxon Valdez was under the control of the third officer. He had slept for only six hours during the preceding 48 hours and was therefore substantially sleep-deprived. It appears that he fell asleep on duty. Media reporting at the time suggested that alcohol was to blame for the accident, but the real culprit was fatigue. In addition to the appalling environmental damage, one man’s tiredness cost his employer more than five billion dollars in punitive damages.
Tiredness contributed to the US Space Shuttle Challenger disaster. On a freezing cold morning in January 1986 the Challenger ascended for ten miles and then exploded, killing the crew of seven astronauts. It later emerged that crucial rubber O-ring seals had failed catastrophically at the low temperatures prevailing that morning. The US Presidential Commission that investigated the disaster concluded that there had been serious flaws in the decision-making processes leading up to the launch. The danger had been foreseeable, but tiredness had contributed to the bad decision to launch despite the icy conditions. Key managers had slept for less than two hours the night before and had been on duty since the early hours of the morning. They were at a dangerously low ebb when the fateful decision to launch was taken. The official report noted that ‘fatigue is not what caused the accident, but it didn’t help the decision-making process’. It also commented that ‘working excessive hours, while admirable, raises serious questions when it jeopardises job performance, particularly when critical management decisions are at stake’. Bear in mind that when official investigations search for the causes of disasters they instinctively focus on tangible, physical causes like rubber O-rings and air temperatures; intangible human factors like fatigue are seldom in the forefronts of investigators’ minds.
Lack of sleep has contributed to, if not caused, a string of disasters and near disasters in nuclear power plants. Many of them occurred in the early hours of the morning – a common feature of sleep-related accidents – and stemmed from failures by human operators to make sensible decisions when faced with the relevant information. Research has confirmed that nuclear power-plant operators who work night shifts experience real problems with sleepiness, distractibility and poor alertness. Even if they are not particularly sleep-deprived, they are unlikely to perform well in the early hours of the morning. And that is when the accidents happen.
The worst nuclear incident so far in the USA took place in March 1979, when the reactor at the Three Mile Island power station near Harrisburg in Pennsylvania came close to meltdown. The near-disaster at Three Mile Island arose in the early hours of the morning, after operators failed to recognise what their instruments were plainly telling them – namely, that an automatic valve had closed, cutting off the water supply to the coolant system. The reactor shut itself down automatically, as it was designed to do when a malfunction like that occurred. But a series of errors by the human operators led to a dangerous loss of coolant from the reactor core and almost turned an incident into a catastrophe. Radioactive gases were released from the partially exposed reactor core, but the containment vessel fortunately prevented them from escaping into the environment. Although no one died as a direct result of the Three Mile Island accident, it had a massive impact on the American nuclear industry. The damaged reactor took ten years to decontaminate and remained unusable. Fatigue is believed to have contributed to the operators’ repeated failures to handle the incident correctly.
The worst nuclear accident thus far in history occurred at the Chernobyl nuclear power station in April 1986. It too was sleep-related, and started in the early hours of the morning when the operators were at their lowest ebb. The disaster happened when the engineers operating one of the station’s four nuclear reactors made a series of irrational judgments. They attempted an ill-conceived experiment that involved shutting down the reactor’s regulatory and emergency safety systems and withdrawing most of the control rods from the core, while allowing the reactor to continue running. The operators exhibited the alarming propensity to take inappropriate risks that is characteristic of tired people. As a later report put it, they behaved ‘like intelligent idiots’.
The reckless behaviour of Chernobyl’s operators caused a chain reaction. At 1:23 a.m. on the morning of 26 April a series of explosions blew the reactor apart. There was a partial meltdown of the reactor’s graphite core and it caught fire. Large amounts of radioactive material were released into the environment – several times the amount created by the atom bombs dropped on Japan in World War Two. Some of it was carried by winds and contaminated several western European countries, including France and the UK. Thirty-two people at the Chernobyl plant died at the time of the accident and several more died soon after from severe radiation exposure. The long-term damage to the health of populations living in affected areas remains a matter of controversy, but it is undoubtedly huge. Several thousand people have died, or will die, as a result.
Over and over again, man-made disasters like Chernobyl and Exxon Valdez have occurred at night or in the early hours of the morning, when people’s reactions and judgment are at their weakest. We saw earlier that drivers are much more likely to have a serious crash late at night than in the middle of the morning. Almost everyone who works night shifts displays signs of sleepiness and impaired performance, and it is not difficult to see why. Working at night forces people to perform at a time when their biological clocks are telling them to sleep, and to sleep when their biological clocks are telling them they should be awake. They perform worse when they are at work, and they are less able to sleep when they go home, as a result of which they become tired and accident-prone. Add chronic sleep deprivation to the brew and you have a potentially lethal concoction. And we all have to live with the consequences.
The price of eternal vigilance is liberty (#ulink_2e1871fd-95d6-5a4a-840f-c5b271f36faa)
Care is heavy, therefore sleep you.
Thomas Dekker, Patient Grissil (1603)
If society were to recognise the true importance of sleep, then attitudes towards tiredness on the roads and in the workplace might become more enlightened. In a more sleep-conscious world it would no longer be socially acceptable, let alone admirable, for people to drive or turn up for work suffering from severe fatigue, any more than it is now acceptable to be drunk in the workplace or behind the wheel of a car. Napping during working hours would be tolerated and even encouraged, rather than stigmatised as a sign of sloth, drunkenness or illness. Meanwhile, society continues to turn a blind eye to people driving cars, flying aeroplanes, practising medicine, operating safety-critical machinery and running nations when they are mentally and physically impaired by lack of sleep.
In the next chapter we shall see that sleep-deprived people are bad at making decisions and communicating those decisions to others. Their judgment is impaired, they are easily distracted, they respond poorly to unexpected information, they lack flexibility, they persist with inappropriate solutions to problems and they are prone to taking foolish risks. These are not the characteristics any of us would wish to see in the people who make life-and-death decisions in the corridors of power, hospitals, flight decks or nuclear power stations.
3 Dead Tired (#ulink_d0cf0e7a-1da5-5fa3-893d-dcbfe8fec2a7)
You lack the season of all natures, sleep.
William Shakespeare, Macbeth (1606)
Does it really matter that many people in industrialised countries no longer get enough sleep of sufficient quality at the right times? We have seen one reason: the fact that sleepiness causes accidents. But far more than that, inadequate sleep matters because of what it does to our minds and our bodies each and every day.
Sleep is eloquent in its absence. We know that if we miss a night’s sleep we will feel bad the next day. But the unpleasant sensations of acute fatigue evaporate after a good night’s sleep and we soon forget. Far less obvious are the insidious, cumulative consequences of seldom getting quite enough sleep, night after night, week after week. Chronic sleep deprivation creeps up on us. It has pervasive effects on our mood, social skills and mental abilities – especially judgment, creative thinking and problem solving. It can also impair our physical health and make us more vulnerable to disease, as we shall see in the next chapter. However, the first and most obvious symptom of insufficient sleep is sleepiness, and that is where we shall start.
Sleepiness (#ulink_5308485c-ae0c-57db-bf98-8a1a2a23d417)
Life is one long process of getting tired.
Samuel Butler, Notebooks (1912)
The longer you go without sleep, the sleepier you feel. Objective measurements prove that there is indeed a close relationship between sleep deprivation and sleepiness. That relationship is ‘dose-dependent’, which means that the longer you have been deprived of sleep, the faster you will fall asleep when given the opportunity. Really tired people can fall asleep almost anywhere, as William Shakespeare observed:
Weariness
Can snore upon the flint, when resty sloth
Finds the down pillow hard.
If you are able to lie on a hard floor and go to sleep immediately during the middle of the day, you are probably sleep-deprived. (An obvious point, but no less true for that.)
