The Art of Manliness Podcast

Episode: Sleep Like a Caveman
Date: February 4, 2025
Host: Brett McKay
Guest: Dr. Marijn Vandelaar, Sleep Therapist and Author of How to Sleep Like a Caveman: Ancient Wisdom for a Better Night's Rest

Episode Overview

In this episode, Brett McKay delves into the history and science of sleep with Dr. Marijn Vandelaar, a sleep therapist who explores what we can learn from our prehistoric ancestors. Drawing on findings from hunter-gatherer tribes, Dr. Vandelaar dispels persistent sleep myths, highlights misleading modern sleep optimization trends, and offers actionable strategies—rooted in ancient wisdom—to help listeners improve their rest, especially for those plagued by insomnia.

Key Discussion Points & Insights

1. Personal Journey With Sleep Issues

• Dr. Vandelaar battled chronic insomnia for three years, experiencing feelings of "hopelessness and helplessness," which informs his empathetic, patient-focused approach.
  Quote:

  "I was feeling very hopeless and helpless because I was trying to control the sleep problem and checking my alarm clock, and it actually pushed me further away from a good sleep." (03:22)

2. How Do We Know How Cavemen Slept?

• No direct records exist, but research on modern hunter-gatherer tribes (notably the Hadza of Tanzania) provides strong clues, given their environmental similarities to prehistoric humans.
  • Hadza sleep patterns are shaped by natural factors like light and temperature.
    Quote:

  "What we can do is we can look at people that still live in the same circumstances like we did when we were cavemen." (04:36)

3. Insomnia in Evolutionary Context

• Night awakenings were adaptive for tribal safety—being awake during the night helped detect threats.
• Hunter-gatherers are awake "over two hours on average during the night," yet see this as normal, not problematic.
  Quote:

  "Being awake during the night was actually kind of a safety thing." (05:28)

4. Rethinking Sleep Duration and Efficiency

• Hunter-gatherers average 6.2–6.5 hours of sleep per night, plus brief naps, even though they spend 9+ hours in bed.
• Western focus on 8-hour, uninterrupted sleep is both historically unfounded and anxiety-inducing.
• High expectations around "sleep efficiency" (percentage of time asleep in bed) are unrealistic by natural standards.
  Quotes:

  "They sleep between 6.2 and 6.5 hours on average per night." (06:38)
  "If you look at the media, they usually say that you have to have a sleep efficiency above 85%. But that would mean that the whole Hadza tribe would actually be a bad sleeper while they themselves don't see themselves as bad sleepers." (07:44)

5. Subjective vs. Objective Insomnia

• Insomnia is usually a subjective complaint—trouble falling or staying asleep plus daytime impairment.
• Discrepancy often exists between patient-reported sleep and objective measures (like sleep studies). The brain may not register sleep for up to 30 minutes after actually falling asleep. Quote:

  "In general it takes about 20 to 30 minutes for a person to realize that they are sleeping, if they are sleeping." (10:41)

6. Insomnia: East vs. West

• Only 1.5–2.5% of Hadza report regular sleep problems versus 20% in Western societies, mainly due to difference in perception.
  • Westerners see night awakenings as a problem; the Hadza do not.
    Quote:

  "That's 10 times bigger than in the Hadza tribe...because the Hazda tribe, if someone's waking up for an hour or two, they don't see that as a problem." (11:10-11:37)

7. Takeaways for Modern Sleepers

• Nighttime awakenings are natural; frustration and obsessiveness worsen the experience.
  • If awake and calm, stay in bed; if agitated, get up and do something relaxing, then return when sleepy. Quote:

  "If you're in the bed awake and you feel quite relaxed, then I think a good thing is to be aware of the fact that being awake is actually quite normal." (12:19)

8. Changing Sleep Needs with Age

• Sleep quality and quantity often decrease with age; this is adaptive from an evolutionary perspective (sentinel hypothesis). Quote:

  "As people age, they're actually better able to wake during the night. So if older people lose their function of more hunting and gathering, then they have more function during the night because they are more awake..." (15:02)

9. Sleep Duration, Health Risks, and Media Myths

• Seven hours is the "magic number"; less than 5–5.5 or more than 9 hours linked to higher mortality, but causality isn't proven.
• Real dangers (increased cardiovascular/health risks) are linked to sleep apnea, not insomnia. Quote:

  "If you look at mortality, then you see that people who sleep less than five to five and a half hours and more than nine hours are actually at risk..." (16:14)

10. Environmental Factors: Light, Temperature & Seasons

• Consistent bright light exposure in the morning/afternoon (ideally outside) is key for healthy sleep rhythms.
• Evening: dim lights and cool down the house.
• Seasonal sleep differences (longer in winter, shorter in summer) are natural. Quotes:

  "Even a walk of 20 to 30 minutes might do, just not sitting behind your desk, eating your sandwich there, but going outside might do the trick already." (20:42)
  "They say between 16 and 18 degrees Celsius (about 60–68°F) in your bedroom." (23:48)

11. Myths: Blue Light, Phones, and Sleep Hygiene

• Blue light from smartphones is not significant enough to disrupt sleep; screens emit too little lux.
• Main issue with screens is mental stimulation, not light.
• For some, light smartphone use or TV helps to distract a busy mind and fall asleep—as happened for Dr. Vandelaar. Quotes:

  "A lot of smartphones don't exceed 10 lux and you need more than 10 lux ... to stimulate your biological clock." (21:32)
  "For some people, using a smartphone might even help to fall asleep...It really depends on what type of person you are." (22:19)

12. Movement and Sleep

• Daytime physical activity builds up adenosine (“sleep pressure”), making it easier to both fall and stay asleep.
  • Avoid strenuous exercise immediately before bed. Quotes:

  "Being more active actually makes you more sleepy and tends to give you more rest, so you fall asleep more easily..." (26:21)
  "If you exercise too much, like one to two hours before going to bed, that might create more problems falling asleep." (27:13)

13. Social Sleeping: Partners, Tribes, and Safety

• In the past (and in Hadza today), people slept in groups for safety.
• Partners subjectively feel they sleep better together, even if measurable sleep quality can dip.
• If restless partners cause issues, options range from separate mattresses/blankets to sleeping in another room. Quotes:

  "They sleep with 20 to 24 people around a fire. And we think that the same thing happened in the past..." (28:38)
  "If you have a partner that's totally tired and worn out, then I think that's not a good thing either...discuss it with each other." (29:48)

14. Hunter-Gatherer Sleep Hygiene

• Wind-down routines: gather around the fire, tell calming stories, avoid stressful topics or activities.
• Westerners rush from activity straight to bed—change that by introducing a 1–1.5 hour wind-down period with dim lights, relaxing activities. Quote:

  "Sometimes the thing with us is that we run, run to the bed and then expect for us to sleep immediately. And I think that's not how it works." (30:54)

15. Sleep Technology: Trackers and Sleep Diaries

• Sleep trackers are unreliable for measuring deep/REM sleep; may worsen insomnia by obsession ("orthosomnia").
• Sleep diaries/logs are preferable for those with insomnia to spot true patterns over time. Quotes:

  "If you're a bad sleeper, I would not recommend [sleep trackers]...they are very inaccurate..." (32:20)
  "For insomnia, it helps very well...one of the treatment steps we do...is using a sleep diary." (33:54)

16. Evidence-Based Treatment: CBT for Insomnia (CBT-I)

• Most effective for insomnia: Cognitive Behavioral Therapy for Insomnia (CBT-I).
  1. Psychoeducation – dispels myths, reframes beliefs about sleep.
  2. Stimulus Control – only use bed for sleep/sex, leave bed if stressed.
  3. Sleep Restriction – temporarily limit time in bed to build up sleep pressure and reestablish natural patterns.
  4. Sleep hygiene – optimize light, temperature, routines.
  • Sleep restriction is tough at first but usually yields dramatic improvement in 4–6 weeks. Quotes:

  "The behavioral techniques are things that people can do to really give their sleep a boost and not be awake stressed out during the night..." (35:01)
  "[Sleep restriction]—shortening your bedtimes to create more sleepiness...a very powerful method that usually works within a couple of weeks." (37:17)

Notable Quotes & Memorable Moments

• On perfectionism and sleep:

  "Let the perfectionism go a little bit and be more relaxed around being awake during the night." (42:19)

• On clocks and insomnia:

  "Not watching the time...if you watch the time, then it takes up to 20 minutes longer to fall asleep again." (41:28)

• Reassuring the anxious sleeper:

  "You don't need eight hours of sleep, you're not going to die...Just reassuring people like, you're fine, you're not going to die." (36:16)

Important Timestamps

• [03:22] Dr. Vandelaar’s struggle with insomnia and treatment philosophy
• [04:36] How science uncovers prehistoric sleep practices
• [05:28] Night awakenings as evolutionary safety mechanisms
• [06:38] Hunter-gatherer sleep duration and misconceptions
• [11:10] Insomnia prevalence: Western world vs. Hadza tribe
• [12:19] What to do when you wake up at night
• [15:02] Why older people wake up more at night
• [16:14] Sleep-duration health myths, cause vs. correlation
• [20:42] Importance of morning and afternoon sunlight
• [21:32] The blue-light myth
• [23:48] Ideal bedroom temperature
• [26:21] Physical activity’s impact on sleep
• [28:38] Sleeping in groups, historic and modern
• [30:54] Hunter-gatherer bedtime wind down routines
• [32:20] Pitfalls of sleep tracking technology
• [35:01] CBT-I steps and sleep restriction explained
• [41:28] The power of not watching the clock
• [42:19] Final advice on sleep and perfectionism

Actionable Advice & Key Takeaways

• Night awakenings are normal, not pathological.
• Obsession with ideal sleep (8 uninterrupted hours) is counterproductive.
• Don’t check the time when you wake up—it prolongs wakefulness and anxiety.
• Prioritize daylight in the morning/afternoon and dim your environment at night.
• Physical activity builds “sleep pressure.”
• Consider group sleeping logistics for comfort—but sleeping apart is fine if it improves rest.
• Tech-based sleep trackers are inaccurate and may worsen anxiety; sleep diaries are better.
• Most effective insomnia intervention: CBT for Insomnia (CBT-I)—including sleep restriction, psychoeducation, and behavioral change.

Final Thought:
“Let the perfectionism go a little bit and be more relaxed about being awake during the night.” (42:19)

To learn more, visit Dr. Marijn Vandelaar’s website or check out How to Sleep Like a Caveman. Show notes are available at [AOM is cavemansleep].