Why We Sleep: The New Science of Sleep and Dreams
By Matthew Walker | Penguin Press | $22.99 | 368 pages
Sleep has been a bestselling topic for a few years now, so another book on the topic — even one as good as this — comes as no surprise. Interest probably peaked with Arianna Huffington’s call to action, The Sleep Revolution, but the TED talks, special issues of New Scientist and media stories about sleep’s role in health, wellbeing and even beauty have kept rolling out. It’s hardly surprising, of course — worries about sleep are universal.
Matthew Walker is well-qualified to add his voice to this debate. He has been researching sleep and sleep-related phenomena for several decades now and has worked with some of the other leading sleep researchers of our time.
In Why We Sleep he presents the science of sleep in a detailed yet very accessible manner. The scholarship may not interest all readers, but the book is structured so that it needn’t be read right through, or even in order. In fact, Walker encourages readers to focus on the parts that are of most interest or use to them. And he won’t take offence in the slightest if we nod off at some points — in his view, the more shut-eye the better.
He begins by explaining the biological mechanisms that regulate sleep and how, for better and for worse, we and our environment manipulate them. Unusually, he includes an entertaining discussion of sleep types across animal species, with both parallels and contrasts to human sleep, and some hypotheses about the way that human sleep has, and will, evolve. This chapter is the foundation on which Walker builds the rest of the book.
He goes on to argue why sleep should be a priority for individuals, and also a priority for employers and communities. This is by no means a new argument, but he develops the point very persuasively. Underpinned by laboratory and field-based evidence, his discussion of the impact of inadequate or disrupted sleep on our daytime performance, mood, health and wellbeing is clear and cogent. He highlights the fact that while one night’s bad sleep has acute, short-term effects, the implications of cumulative or chronic sleep disruption can be severe.
Why We Sleep then heads off into an entertaining and challenging discussion of a topic — how and why we dream — about which we knew very little until quite recently. Walker presents a brief history of our understanding and interpretation of dreams, from beliefs among ancient Egyptians and Greeks (that dreams were handed down from the gods), through Aristotle (that dreams originated in waking events) and Freud (that dreams originate in the unconscious), to our modern understanding. He discusses the value of dreaming for mental, emotional and psychological wellbeing, and his intriguing account of the role of dreams in creativity is certainly worth thinking about (or sleeping on).
The book’s closing chapter is a call to arms for government, industry, communities and individuals. So many elements of Western life either limit opportunities for sleep or encourage us to prioritise wakefulness. Technology; work hours and work arrangements; lighting; pills to help us sleep and pills to keep us awake — the list goes on. Walker challenges us to prioritise sleep in order to be able to get the most from the rest of our lives.
Sleep is often viewed as the activity (or non-activity) that we do when all the day’s important tasks are finished. Matthew Walker attempts to reframe our idea of sleep so that we will come to treat it as critical for getting all those other tasks done well, safely and without sacrificing our health.
My only disappointment with this book is its patchy acknowledgement of the published literature. Walker names some scientists and cites some studies, and doesn’t provide full references for all of them. Although he expresses due humility, he does make it sound like the majority of the published work was done in the United States, if not in his own laboratory.
As a sleep researcher in Australia, I have a certain perspective, of course, but no one would deny that significant advances have been made by scientists not only here but on other continents outside North America. (Among them is Till Roenneberg, whose fascinating book I reviewed for Inside Story in 2012.) Walker’s main audience is American, of course, but readers everywhere should bear in mind the international nature of the research effort in this field. ●
