Sleep tips for the science-minded:

An evidence-based guide to family sleep problems

© 2008 Gwen Dewar, all rights reserved

Looking for evidence-based sleep tips?

These articles review the latest relevant research in anthropology, brain science, sleep science, and pediatrics.

They include discussions of baby sleep and the best-available evidence regarding child sleep requirements.

In addition, there are articles about

• Nightmares and night terrors in children

• Nighttime fears and separation anxiety

• Night wakings in children and how to cope with them

• Children who refuse to go to bed

• The "cry it out" method of sleep training and its alternatives

• Gentle, “no cry” sleep training programs

Below I provide (1) a brief introduction to the anthropology of sleep, and (2) an overview of the articles in this collection.

1. The anthropology of sleep

Most of the sleep tips you’ll find in Western parenting books and magazines are based on cultural assumptions about what constitutes good sleep. In many Western countries, people are expected to

• sleep through the night without interruption

• avoid daytime naps, and

• insist that their children sleep alone

In addition, many people subject themselves to artificial lights and electronic entertainments before bedtime. These influences re-set the brain’s internal clock and make it difficult to fall asleep.

Viewed from an historical and anthropological perspective, such practices are unusual (Worthman and Melby 2002; Jenni and O’Connor 2005).

They also represent a profound departure from the likely sleep patterns of our ancestors.

If you’re struggling with sleep problems--and trying to evaluate popular sleep tips for coping--it may be helpful to keep these ancestral sleep patterns in mind:

Our ancestors probably didn’t satisfy all their sleep requirements in one, lengthy nocturnal sleep bout. Instead, people probably slept for a few hours at a time, awakened for an hour or more, and then slept again. In other words, nobody—not even adults—were expected to “sleep through the night.” This was the pattern in pre-industrial Europe (Ekirch 2005), and it’s still the pattern in many non-Western societies today (Worthman and Melby 2002). For more information, see my article on night wakings. It includes sleep tips for coping with children who awaken frequently at night.

Our ancestors didn’t have clocks and rigid work schedules that required them to be awake and alert at the exactly same time every day. As a result, they would have had more “downtime,” more flexibility regarding the timing of sleep, and more naps. Again, this is the pattern in many non-Western cultures today (Worthman and Melby 2002).

Throughout evolutionary history, humans have organized their activities by the rising and the setting of the sun. Without electricity, they spent more time in darkness, and avoided the circadian rhythm sleep disorders caused by artificial lighting at night.

Without modern technologies to protect them, our ancestors’ most pressing sleep problem was getting through the night without being attacked by predators or intruders. People who “slept like logs” or who were unfazed by mysterious night noises would have been less likely to survive and pass on their genes. People who slept alone--without the benefit of multiple eyes and ears to help keep watch--would have been at a similar disadvantage. Seeking safety in numbers, our ancestors slept in groups.

For the reasons just stated, children--the most vulnerable members of their group--weren’t left to sleep alone. And if children cried out in the night--attracting the attention of predators--it made sense to quiet them down as soon as possible.

Implications for you and your family

This review of ancestral sleep patterns suggests several important points. For most of human history

• Kids weren’t expected to sleep through the night.

• Their internal, biological clocks were rarely out-of-sync with the natural 24-hour day.

• If children or their parents were tired during the day, their schedules permitted them to nap.

• Being easily aroused during the night was normal and adaptive. So was being cautious or fearful about things go bump in the night. So was responding promptly to your child’s cries.

• Kids didn’t sleep alone. Being alone meant abandonment, injury, or death.

Does this mean we must live like Pleistocene hunter-gatherers to sleep well? No. But it should make us question the cultural practices and sleep tips that depart radically from the ancestral pattern. And it offers some helpful insights for solving child sleep problems.

First, many child sleep problems aren’t pathological in the sense of being “unnatural” or biologically abnormal. When kids suffer from nighttime fears or resist going to bed by themselves, they may be expressing psychologically normal, healthy responses.

Second--no matter what any sleep researcher, pediatrician, or nosy relative might say--your urge to soothe your child to sleep is biologically normal. Parents should keep this in mind if they feel pressured to try out sleep tips or sleep training programs that violate their parental instincts.

Third, many sleep problems may be caused by a poor fit between our cultural practices and our needs. For example, Western children often resist going to bed at night. In part, these bedtime battles may be caused by the practice of solitary sleeping--a Western custom that may trigger separation anxiety in young children.

The bottom line?

Before you take any sleep advice to heart--or let someone convince you that your family’s sleep practices are “wrong”--you should exercise a healthy skepticism.

An anthropological approach to sleep can help us discover which aspects of sleep are essential and which aspects are subject to cultural variation. The articles in these pages will help you decide which sleep solutions are best for you and your children.

2. Evidence-based sleep tips

Baby sleep

Western sleep practices may be poorly matched to the needs of some kids and adults (Jenni and O’Connor 2005). For babies, the fit may be even worse. In particular, Western cultural expectations about solitary sleeping and “sleeping through the night” may cause families considerable distress.

But whether you accept or reject Western sleep practices, there is much you can do to minimize sleep problems during infancy. For information about sleep in infants--including sleep requirements, sleep patterns, and a variety of practical sleep tips--see this collection of articles on baby sleep.

How much sleep does your child need?

How can you tell if your child is sleeping enough? When I first began researching sleep requirements, I assumed that those authoritative charts we see published everywhere--the ones telling us that the average newborn needs 16 hours of sleep, for example--were based on scientifically-established, physiological needs.

I was wrong. It turns out that no one really knows how much sleep children need for optimal health and growth. And kids, like adults, may vary considerably in their individual requirements.

So if you really want to understand your child’s personal sleep needs, you need to go beyond the published sleep charts. In this article on sleep requirements, I review the latest scientific evidence and discuss ways to apply this information to your family.

In addition, my article about sleep restriction outlines the symptoms and signs of insufficient sleep in babies, children, and adults.

Why can't your child sleep?

According to Western sleep studies, "bedtime resistance" and frequent night wakings are among the most common sleep complaints that parents report to their pediatricians (Mindell et al 2006).

What causes kids to resist bedtime? Or awaken frequently at night?

These sleep problems may stem from a variety of causes, and it’s important to understand why your child can’t sleep before you attempt treatment.

In many cases, kids may suffer from nocturnal fears and anxieties. For more information, see my article on nighttime fears in children. It explores the evolutionary basis for nighttime fears and discusses why kids are biologically unprepared to handle nighttime fears on their own. It also offers practical advice for helping your child overcome her fears.

For other sleep tips, see my articles on bedtime problems, night wakings, and nightmares and night terrors.

The article on bedtime problems includes a trouble-shooting checklist to help you identify why your child may have trouble falling asleep.

The article on night wakings reviews the science of disrupted sleep, and includes practical sleep tips for improving the quality of your child’s sleep.

The article on nightmares and night terrors helps you distinguish between these two conditions, and offers sleep tips for treating them.

Sleep training

The Ferber method--also called “graduated extinction”--is one of the most famous sleep training programs. It is also one of the most controversial, primarily because it involves a degree of “cry it out.” For a detailed account of graduated extinction--including arguments for and against its use--see this article on the Ferber method.

As I note in this article, the Ferber method appears to be very effective in some respects. However, it's clearly inappropriate for some children, and despite headlines to the contrary, the jury is still out regarding the possibility of negative side effects.

For information about alternatives to the Ferber method, see this article on “no cry” sleep training.


References: Family sleep tips and topics

Ekirch AR. 2005. At Day's Close: Night in Times Past. New York: WW Norton.

Jenni OG and O’Connor BB. 2005. Children’s sleep: An interplay between culture and biology. Pediatrics 115: 204-215.

Mindell JA, Kuhn B, Lewin DS, Meltzer LJ, Sadeh A and the American Academy of Sleep Medicine. 2006. Behavioral treatment of bedtime problems and night wakings in infants and young children. Sleep 29: 1263-1281.

C.M. Worthman and M. Melby. 2002. Toward a comparative developmental ecology of human sleep. In: Adolescent Sleep Patterns: Biological, Social, and Psychological Influences, M.A. Carskadon, ed. New York: Cambridge University Press, pp. 69-117.

Content last modified 3/09