Everything You Know About Sleep Is Wrong (E211)

But David, we've been told for decades that modern life is causing a sleep epidemic, yet your research indicates that people in post-industrialized societies actually sleep longer and more efficiently than hunter-gatherer societies.

So what's going on?

Yeah, Jesse, so...

I first came across this idea of the sleep epidemic when most people did.

And that was in 2014 when the CDC released a very scary proclamation that we were in a sleep epidemic.

And that in the United States, we were the worst sleeping cohort that had ever been measured.

And so we were like it was painting this picture of sort of a sleep dystopia, if you will.

Like there's no in the history of humanity, there's no people or society that have slept worse.

And that was right around the time I was beginning my foray into sleep research in the field.

and in particular national geographic was funding my research to work with small-scale foragers particularly the hadza they're one of the last groups in the planet to still hunt and forge for most of their calories and my intuition was that I was calling bullshit in my head.

I was thinking, having done work with small-scale foragers, my intuition is that indeed the sleep epidemic hypothesis wouldn't be supported if we were to get a massive cross-cultural comparative data set of sleep across large-scale societies and across small-scale societies.

So let me define these two terms because it's super important for the overall argument.

So large-scale is on the grid.

A large-scale society is provisioned.

99% of everyone that lives in a large-scale society gets 99% of their calories from a place they exchanged an abstract currency that represents in the abstract energy that we exchange for our calories, right? So in these large-scale on-the-grid societies, you have...

ready access to electricity you have comfortable uh sites indoors that are temperature regulated they're light regulated and this is very different from a small scale society a small scale society you have 24 7 access to whatever the light and temperature is in the natural environment that our ancestors evolved in for quite some time i'm sure we'll get there today and And you're getting all your calories from the activities that you're investing in that day.

And so myself and my postdoc and some collaborators that we've been working the past 10 years to generate a massive data set in some for the proceedings B paper that came out last year in 2025, where we tested the sleep epidemic hypothesis, we have 54 different societies and we broke them into this on the grid, off the grid, small scale, large scale.

And when we ran the analyses, it was quite stark and nuanced, actually.

So when we look at sleep duration, interestingly, in the large scale societies, it's averaging globally when we clump them all together and we control over a host of factors like age, sex, all these really crucial things.

We see that the average is about 7.1.

When we look at small scale in terms of hours of duration, when we look at small scale, it's 6.4. That's a delta of about 0.75 hours.

So that's like 45 minutes.

As someone who's studied sleep architecture for the past decade, I can tell you 45 minutes has a significant difference.

increase or decrease on the overall results of your sleep.

So that was 45 minutes.

But David, we've been told for decades that modern life is causing a sleep epidemic, yet your research indicates that people in post-industrialized societies actually sleep longer and more efficiently than hunter-gatherer societies.

So what's going on?

Yeah, Jesse, so...

I first came across this idea of the sleep epidemic when most people did.

And that was in 2014 when the CDC released a very scary proclamation that we were in a sleep epidemic.

And that in the United States, we were the worst sleeping cohort that had ever been measured.

And so we were like it was painting this picture of sort of a sleep dystopia, if you will.

Like there's no in the history of humanity, there's no people or society that have slept worse.

And that was right around the time I was beginning my foray into sleep research in the field.

and in particular national geographic was funding my research to work with small-scale foragers particularly the hadza they're one of the last groups in the planet to still hunt and forge for most of their calories and my intuition was that I was calling bullshit in my head.

I was thinking, having done work with small-scale foragers, my intuition is that indeed the sleep epidemic hypothesis wouldn't be supported if we were to get a massive cross-cultural comparative data set of sleep across large-scale societies and across small-scale societies.

So let me define these two terms because it's super important for the overall argument.

So large-scale is on the grid.

A large-scale society is provisioned.

99% of everyone that lives in a large-scale society gets 99% of their calories from a place they exchanged an abstract currency that represents in the abstract energy that we exchange for our calories, right? So in these large-scale on-the-grid societies, you have...

ready access to electricity you have comfortable uh sites indoors that are temperature regulated they're light regulated and this is very different from a small scale society a small scale society you have 24 7 access to whatever the light and temperature is in the natural environment that our ancestors evolved in for quite some time i'm sure we'll get there today and And you're getting all your calories from the activities that you're investing in that day.

And so myself and my postdoc and some collaborators that we've been working the past 10 years to generate a massive data set in some for the proceedings B paper that came out last year in 2025, where we tested the sleep epidemic hypothesis, we have 54 different societies and we broke them into this on the grid, off the grid, small scale, large scale.

And when we ran the analyses, it was quite stark and nuanced, actually.

So when we look at sleep duration, interestingly, in the large scale societies, it's averaging globally when we clump them all together and we control over a host of factors like age, sex, all these really crucial things.

We see that the average is about 7.1.

When we look at small scale in terms of hours of duration, when we look at small scale, it's 6.4. That's a delta of about 0.75 hours.

So that's like 45 minutes.

As someone who's studied sleep architecture for the past decade, I can tell you 45 minutes has a significant difference.

increase or decrease on the overall results of your sleep.

So that was 45 minutes.