I get a pretty strong pseudoscience vibe from it.

From a previous post:

I got a strong motivated reasoning/bullshit vibe from Walker in this interview: https://www.npr.org/2018/07/20/630792401/sleep-scientist-war...

Particularly this section:

> “Sleep is not like the bank. So you can't accumulate debt and then try and pay it off at a later point in time. And the reason is this - we know that if I were to deprive you of sleep for an entire night - take away eight hours - and then in the subsequent nights, I give you all of the sleep that you want - however much you wish to consume - you never get back all that you lost. You will sleep longer, but you will never achieve that full eight-hour repayment as it were. So the brain has no capacity to get back that lost sleep...”

I don’t think this follows - seems likely to me that sleep is not some linear time thing and that there’s a standard overhead that doesn’t need to be repeated to extend and make up the time. This feels like a symptom of not understanding the mechanism and making a bad assumption.

I also found the “I won’t mention the cognitive failures I can detect” irritating. If there’s some actual thing to mention, say it - this kind of thing sets off alarms for me.

It doesn’t surprise me that the rest is similarly bad.

[0]: https://guzey.com/books/why-we-sleep/

https://statmodeling.stat.columbia.edu/2019/12/27/why-we-sle...

now, it's obvious to me that if I don't get 8 hours of sleep a night, my brain stops functioning properly and my entire life goes to shit very quickly. So I was happy to see a very popular book advocating sleeping well, and hopeful that if lots of people read it, they might have more respect for other people's sleep schedules.

The critic, Alexey Guzey, seems to be a guy who needs less sleep than I do, and also a guy who is into life-hacking/self-improvement type stuff. There's definitely a type of person who thinks "sleep is for the weak". I think he probably does have a bias towards sleeping less.

But I think the problems he points out about the book are pretty serious.

In particular, it seems that claims around sleep and longevity and other health outcomes (e.g. injury rates, cancer) are often unreliable or based on misinterpreted studies, and one case involves eliding data that contradicts the result.

Now, having myself experienced chronic sleep deprivation, and dealt with people who think they don't need to sleep but definitely do, I think the basic argument of the book is probably correct. But as the last line of that post quotes, "Good ideas do not need a lot of lies told about them to gain public acceptance".

For those interested in someone who created a refutation to Matthew Walker's "Why We Sleep"