Why We Sleep

I decided to read this book after a friend of mine posted a number of interesting quotes from it. Sleep has fascinated me for a long time, and for some reason I carried the assumption that we still do not know much about why we sleep or what exactly happens when we do. Added to this is the fact that I have regularly gone with 6 or less hours of sleep during the work-week over the last few years due to a 6:30am start time (meaning a 5am wake time + 1hr commute) and being a night owl. Regular good sleep has thus evaded me for quite some time, and I have had mixed feelings about it. Part of me embraced the “I’ll sleep when I’m dead” mentality that sees sleep as nothing but an obstacle to further productivity, while another part of me recognized that sleep deprivation was having an undeniable effect on my physical, mental, emotional, relational, and spiritual health.

To put it simply, this book is an accessible summary of the most important scientific findings to have emerged in the ever-advancing field of sleep studies. I am by no means familiar with the world of sleep studies, so perhaps there are differing schools of thought, but the impression I got from the book was that we have learned an awful lot about sleep in the last few decades, and that this information has not yet become widely spread public knowledge.

The book itself is of considerable length, clocking in at over 300 pages (16+ hours of listening time). There is a lot of information in there, but a lot of it could be distilled down to a list of key findings. Much of the book is an exploration of how those findings were reached and what the implications of them are. Like any field of study, I am sure that some of these conclusions will be revised in the future, but hopefully not with the kind of yo-yo inconsistency that has characterized the science of food and diet (yesterday’s health food is today’s carcinogen, etc).

What were some of the key takeaways?

– Most importantly, you need sleep. That is, unless you are one of the roughly 1% of people who can function with less than 6 hours of sleep and not be impaired.

– If you think that’s you, think again: People are hilariously unable to assess their own level of impairment due to lack of sleep (similar to alcohol). We are self-deceived on this point.

– The two main types of sleep, NREM and REM, are both vital but for different reasons. NREM, among other things, is responsible for pruning memories and transferring short-term memory to long-term memory. REM (dream sleep) “is responsible for forming new neural connections, problem-solving, dreaming, blunting emotional responses to painful memories, reading other people’s facial emotions…” etc.

– Now to scare you into bed: “Sleep deprivation is associated with more severe disease: higher mortality, risk of cancer, heart disease, weight gain, rate of infection, Alzheimer’s, irritability, inflammation.” All of these are solidly demonstrated by peer-reviewed studies.

– Lastly, the effects of sleep deprivation are many: “lowers performance, social fluidity, rational decision-making, memory recall, emotional control, immune system function, response to flu vaccine,” and more.

I came away from this book and a newfound respect and awe for the magical substance and activity we call sleep. As for my sleep habits, I certainly came away chastised for my past neglect of it and motivated to embrace this good gift. The book largely broke the mental connection I had between sleeping and laziness. While this obviously still applies to certain people, our society is one that is chronically and proudly sleep deprived. If there are two ditches we can fall into, our culture is firmly in the ‘too little sleep’ ditch, and quite a ways from the lazy over-sleeping ditch.

The only significant criticism I have to make of the book is one I make as a committed Christian, and which therefore will not be shared by those who do not share my convictions. Simply put, the author, like so many in the world of science, is entirely committed to a purely naturalistic view of biological development. That is, no matter what he discovers about sleep and the human body, no matter how amazing or intricate or fine-tuned or brilliantly designed he finds it to be, he can only ever attribute it to the blind impersonal force of natural selection or the slightly anthropomorphized ‘mother nature’.

Now listen, I am not surprised at this and this little rant is perhaps more of a reflection than a criticism. I don’t realistically expect the author to start questioning his metaphysical assumptions about ultimate reality because he discovers something about how a certain hormone regulates the emotionally healing qualities of REM sleep. Well, sure, it would be nice. It does however demonstrate starkly for me the blind allegiance of the scientific establishment to a secular naturalism, despite the massive problems with the theory of evolution, especially the obvious absence of any compelling model or explanation for the origin of biological life. This is simply glossed over: The edifice has been built already, don’t go asking questions about the foundation – it’s too late for that. Our hubris really cannot handle admitting ignorance or the possibility that we’ve taken a massive 2-century-long wrong turn down a dead end. And those with the intellectual honesty to express doubts about the reigning dogma are quickly ostracized and excluded. Following the evidence indeed.

As for me, this book helped me discover the incredible ways our bodies and minds have been designed, and the crucial role sleep plays in that design. It spoke of a Creator who knows what’s good for us, who designed us to have limits which in our pride we so often try to ignore.

I enjoyed the book, learned a lot from it, and am grateful for it. If you want to learn more about sleep than you ever thought there was to know, get yourself a copy.

“for he grants sleep to those he loves.” (Psalm 127:2)

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