Sleep Training Harms Babies

In our monthly open discussion hour recently at NestedWorld.org, distress over widespread baby sleep training was expressed. Sleep training of babies is encouraged by parent influencers and even pediatricians. The dominant cultural discourse in the USA is that sleep training does no harm. Ay, ay, ay!

The truth is the opposite. Sleep training harms babies. Period.

There is no way around it. You may not notice the damage immediately, but it carries forward in brain and relational dysfunctions, starting with inflammation.

Fact 1: The human infant resembles fetuses of other animals for at least 18 months after birth. For example, the skull plates do not harden until around that time because the brain evolved to double in size in the first year (given evolved nested care).

Fact 2: Because of deep immaturity, the human infant expects an external womb experience during their first 18 months or so. That is, babies expect their needs to be met immediately by nurturers who anticipate and recognize their needs.

It is distressing and painful for a baby when their basic needs go unmet.

But parent advisers think it’s perfectly fine to leave baby alone for hours at a time.

Fact 3: Brain growth requires a pro-growth biochemistry which comes from a loving, supportive environment and the physical closeness of nurturers. Young babies are developing their health, and their health trajectory, for the rest of life.

Sleep training creates an anti-growth biochemistry. When baby is apart from being with the bodies of nurturers, their systems get dysregulated (e.g., heart rate, breathing, brain waves) because infants cannot self-regulate. They need to be co-regulated, just as in the womb.

It may appear to parents that babies ‘self-soothe’ but that is wishful thinking. They are shutting up and shutting down growth in an effort to stay alive.

Fact 4: Young babies are developing their social and emotional intelligence from their social experiences. It doesn’t just happen during the daytime. It’s a 24/7 happening. Absent nurturers leads to infant distrust in self (signals did not work) and in others (not there when I need them).

But: Parents are encouraged to ignore the fact they are shaping child personality and longterm wellbeing through their infant care.

Even veterinarians, who study animals who are much more mature at birth than humans, know that separating baby from mother even for an hour is damaging to the relationship and the offspring’s social development and wellbeing across time.

In fact, the first years of life is when the foundations of relational trust and intelligence are growing at their peak.

But parents are being encouraged to sleep train their infant at 6 weeks, 2 months, 6 months, 10 months. This is torture.

But aren’t there studies showing sleep training is safe?

Fact 5: Published studies of sleep training safety are multiply flawed. If you look at the studies published online, sometimes the journal will keep up the critical comments about the methodological flaws. The studies report on psychological outcomes with such flawed methods that they would never be published in a psychological journal.

What kind of flaws?

• Researchers often have conflicts of interest (e.g., they work at sleep training clinics).
• The researchers adopt no baselines for what is species normal (constant presence of nurturer).
• The outcome measures are inadequate in focusing on short-term instead of multi-year consequences. They examine only a couple of variables, mostly missing infant wellbeing.
• They use parent reports to assess infant wellbeing.
• There is no clear assessment of what the experimental and comparison groups actually did after they were given instructions, but after the period of practice the outcomes are compared as if instructions were followed. [This method is called “intent to treat” which is often used for testing new drugs.)
• No distinctions are made by age of infant.
• The samples are too small to draw conclusions.
• Unethical and incorrect conclusions are drawn from these shoddy studies—for example, claiming that sleep training is safe for all when the results do not show this at all.

Unfortunately, pediatricians likely read only the abstracts and do not realize the many flaws of the studies.

The nuclear family is a difficult place to raise a baby because there is not enough help. Clearly babies (and mothers and fathers) are paying the cost of an undernurturing culture. But in the end, we all pay. The result is a populace of children, adolescents and adults who are dysregulated, unwell, and less than cooperative. The USA is exceptional here in comparison to other high income nations, with its lack of paid parental leave and other family supports.

We evolved to nurture children 24/7 communally, with many helping hands around—grandparents and ‘unties’ nearby to help out with baby care. Multiple nurturers are a key part of our communal evolved nest.

Meanwhile, there are safe ways to co-sleep and bedshare. See cosleeping.nd.edu

For More Details and Information:

Blog posts on infant and toddler sleep: https://sites.nd.edu/darcianarvaez/blog

Read what happens to baby and parent-child relationship in one of my most popular blog posts: “Dangers of Crying It Out”

Bergman, N.J. (2024). New policies on skin-to-skin contact warrant an oxytocin-based perspective on perinatal health care. Front. Psychol. 15:1385320. doi: https://10.3389/fpsyg.2024.1385320

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Narvaez, D., & Tarsha, M. (in press). The Evolved Nest: Sleep training violates baselines for child raising. In J. Rosier (Ed.), Dispelling Cry-It-Out sleep training myths and what to do instead. Routledge. Preprint

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