Why We Sleep: The New Science of Sleep and Dreams, By Matthew Walker
I bought this book out of general interest. It is an international bestseller by a former professor of psychiatry at Harvard Medical School, who is currently a professor of neuroscience and psychology at the University of California, Berkeley.
Here is why I am reviewing this book in a business newspaper.
I believed, as you may, that “pulling an all-nighter” was a badge of honour, a clear sign of commitment and fortitude. US president Donal Trump brags of sleeping only four hours per night. Just last week a client told me, with a hint of pride, that he sleeps less than five hours per night. And he wasn’t the first.
With what we know now, this is about as absurd as bragging that you are a wife-beater, and that you drive drunk!
Erosion by sleep neglect
Consider the facts. Driving without sufficient sleep is the cause of hundreds of thousands of traffic accidents and fatalities each year. In the US, one person dies in a traffic accident every hour due to a fatigue-related error, exceeding road deaths caused by alcohol and drugs – combined.
“Every component of wellness, and countless seams of societal fabric, are being eroded by our costly state of sleep neglect: human and financial alike,” author Matthew Walker explains.
Just to get your attention, consider that reams of reliable research indicate that routinely sleeping less than six or seven hours per night demolishes your immune system, and more than doubles your risk of cancer. It is a key lifestyle factor determining whether or not you will develop Alzheimer’s disease. Sleep deprivation increases the likelihood of your coronary arteries becoming blocked and brittle, which increases the risk of cardiovascular disease, stroke, and congestive heart failure.
Less dramatically, you have probably noticed a desire to eat more when you’re tired. This is because too little sleep increases a hormone that makes you feel hungry and suppresses a hormone that signals food satisfaction.
The need to sleep is a foolish biological phenomenon that evolution should have cleaned out of the system. When you sleep, you cannot fulfil the basic drives of life: to eat and drink, reproduce and protect yourself. And yet, across the animal kingdom, sleeping is a common factor.
Sleep loss epidemic
The World Health Organisation (WHO) has declared sleep loss an epidemic throughout industrialised nations. Two-thirds of adults do not have the recommended eight hours of nightly sleep. "Society’s apathy toward sleep has, in part, been caused by the historic failure of science to explain why we need it," Walker explains. The fact that sleeping persists throughout evolution means there must be tremendous benefits that far outweigh all the obvious hazards and detriments.
In the 1950s and 1960s, scientists used recordings from electrodes placed on the scalp to provide a general sense of the type of brainwave activity underpinning ‘REM’ (rapid eye movement) sleep. 'Deep sleep' describes the bodily state of inactivity, while 'REM sleep' describes high levels of brain activity with the eyes moving rapidly in different directions. The older technology limited our ability to understand what was happening during REM sleep that made it so important.
In the early 2000s, with the advent of brain-imaging machines, we could reconstruct three-dimensional visualisations of brain activity during REM sleep. This has enriched science’s understanding.
Sleeping aids the body by restoring our immune system to fight malignancy, prevent infection, and ward off all manner of sickness. Adequate sleep maintains a flourishing microbiome in your gut which ensures nutritional health. The physical and mental impairments caused by one night of bad sleep dwarfs those caused by an equivalent absence of food or exercise.
Dreaming provides humans with many gifts, among these are nightly neurochemical baths that mollify painful memories, and allow the brain to combine past and present knowledge, and inspire creativity.
It is believed that 'time heals all wounds'. However, Walker suggests it might be that time spent in dream sleep offers a form of overnight therapy. REM sleep dreaming takes the painful sting out of difficult, even traumatic, emotional episodes you may have experienced during the day, offering emotional resolution when you awake the next morning. This happens because REM sleep is the only time during the twenty-four-hour period when your brain is completely devoid of the anxiety-triggering molecule. Sleep is clearly needed for us to heal emotional wounds.
Sleep is also a creative incubator. In the dreaming sleep state, your brain will cogitate on vast amounts of knowledge you have acquired, and then extract overarching rules and commonalities. When we wake we are often able to find solutions to previously impenetrable problems. This is the difference between knowledge (retention of individual facts), and wisdom (knowing what they all mean when you fit them together).
Dmitri Mendeleev formulated the periodic table in a dream, something his waking brain was incapable of. When he awoke he wrote it down, and in only one place was a correction necessary.
The neuroscientist, Otto Loewi, formulated how nerve cells communicate with each other in a dream. For this he received a Nobel Prize.
Paul McCartney’s origination of the songs 'Yesterday' and 'Let It Be' were derived from dreams and then written down. "I couldn’t believe I’d written it. I thought, no, I’ve never written anything like this before. But I had, which was the most magic thing!" he said.
Keith Richards of the Rolling Stones had a similar experience with his music.
Mary Shelley’s dreams provided the vision and narrative for the spectacular gothic novel, Frankenstein.
Laboratory tests have shown how problem-solving abilities increase by 15 to 35 % when participants are emerging from REM sleep compared with daytime performance. The REM sleep dreaming brain is utterly uninterested in bland, common sense, linear type links. In REM sleep, the brain drops the logic guard and ignores the obvious in, favour of very distantly related concepts.
The caffeine test
So, how do you know whether you’re routinely getting enough sleep? The rule of thumb is whether you could go back to sleep at ten or eleven that morning, or whether can you function optimally without caffeine before noon. And of course, whether you would sleep past your waking time if you didn’t set an alarm clock.
Like a loan in arrears, your sleep debt will continue to accumulate. It will roll over into the next payment cycle, and the next, and the next, producing a condition of prolonged, chronic sleep deprivation from one day to another.
The implications for your professional performance or management style should be clear. Coming to work sleep-deprived is no better than coming in hungover. And when next you hear someone brag about how little sleep they get, give them Walker’s book to read, or even just this column.
We need to revise our cultural appreciation of sleep and reverse our neglect of it.
Readability Light --+-- Serious
Insights High +---- Low
Practical High -+--- Low
- Ian Mann of Gateways consults internationally on leadership and strategy and is the author of Executive Update. Views expressed are his own.