This is the second of a two-part post. If you haven’t seen Part one I suggest you read it first.
When I left off I was talking about self-regulation in children and how its early development begins with parents “regulating” babies externally.
Another great piece of concrete scientific evidence on how this works comes from Dr. James McKenna’s co-sleeping studies, which some of you may be familiar with. Among other things, his work showed that sleeping next to a parent (mothers in his studies) helps to regulate a baby’s heartbeat, breathing, body temperature, sleep state and arousal level. The famous kangaroo care studies (by other researchers) have shown similar sorts of things. Near-constant physical contact with an adult body helps premature babies regulate their body temperature and breathing, and simply helps them to thrive.
So, as a parent, your body has a physiological, regulating impact on your baby. You probably already knew that. I sensed it as a new parent but had trouble putting it into words. I touched on that in a previous post.
Back to the specific link between infant feeding and self-regulation, which I explained in my last post. Here’s a really cool thing you might not know. Dr. Stephen Porges’ research (see Part one) has shown that along with providing nutrition and comfort, infant suckling also helps develop the facial muscles and other neural pathways that are essential for smiling and other aspects of social interaction. Some of these mechanisms start to become more functional at around the age of six months, when he says infants become able to engage in self-soothing.
Yikes! Doesn’t this sound like Dr. Porges is saying the same thing as the sleep pundits whose mantra is that infants become capable of self-soothing around sleep at age six months?
Not at all. Which leads me to the even cooler part.
The self-soothing that Porges is talking about is not a solitary pursuit. Rather it’s the enhanced developmental ability to seek out the social interaction that is an infant’s primary source of comfort. Babies have ways of getting us to interact with them before age six months – crying, smiling, waving their arms and legs, looking cute and vulnerable etc. But at around six months they become more aware and consciously active participants in the process, plus they are more capable of being comforted by things other than feeding and physical contact (although those remain important), such eye contact or your soothing voice. Here’s how Porges puts it in one of his articles:
“For humans, maturation does not lead to a total independence from others, but leads to an ability to function independently of other people for short periods. Moreover, humans, as they become more independent of their caregivers, search for appropriate others (e.g. friends, partners, etc.) with whom they may form dyads capable of symbiotic regulation.”
In other words, self-soothing is not about a little baby lying there crying for comfort and then somehow having this eureka moment where he thinks, “You know, I don’t really need Mom or Dad to get back to sleep anymore…. Zzzzzzzzzz.”
It’s more like, “Hey, I’m starting to figure this thing out about how to get Mom or Dad or big brother or Grandma to interact me. And, come to think of it, I’ve noticed that sometimes I can get by just knowing that Mom or Dad is there and paying attention to me.”
Six-month-olds don’t really think like that, of course, but you get the drift. If there is such a thing as “self-soothing” between 6 and 12 months of age, it is the beginning of an enhanced ability to manage the way you seek out social sources of comfort and support. Improved internal biological calming mechanisms, which the baby does not consciously manage, play an important role. They help the baby stay in the calm and alert state which enables her to focus on and participate in back-an- forth social interaction. This “social engagement system,” as Dr. Porges calls it, is a crucial mechanism for recovering from stress and, more generally, managing physiological, emotional, cognitive and social self-regulation (see previous post) throughout life.
Does this relate at all to the self-soothing sleep professionals talk about? Mostly no, but the confound here is that some babies do wake up and go back to sleep on their own. I’d guess that many are physiologically calm when they do so and that their internal calming mechanisms help them go back to sleep. I can’t tell you why some babies are like that and others aren’t – although I’ll bet variations in vagal tone have something to do with it some of the time. Dr. Porges’ research has shown that babies who cry excessively tend to have poorer regulation of the vagal brake. That could explain why some babies are less upset than others when they wake at night and why sleep training goes so much harder with some babies than others.
Bottom line, it’s safe to say that babies who go back to sleep on their own do not do so because they are employing self-calming techniques they learned while being Ferberized.
In fact research by Wendy Middlemiss, of the University of North Texas, suggests that in some cases at least, it’s the opposite. She monitored cortisol levels (cortisol is a hormone that helps mobilize our physiological resources to deal with a challenge or threat) in babies at a New Zealand clinic where they practice a sleep training technique that really does warrant the term “cry it out.” In this clinic, after mothers and babies went through their normal bedtime routine the babies were left in a room to, well, cry themselves to sleep, and the mothers were not allow to go back in (nurses went in to check on the babies but they didn’t offer comfort). Middlesmiss (who does not espouse controlled crying sleep training methods, by the way) and her team measured the babies’ levels of cortisol on the first and third nights of treatment. On the first nights, when the babies were wailing away, they had elevated levels of cortisol (and so did the mothers). On the third night, most of the babies were going to sleep with little or no crying. But their cortisol levels were still elevated.
What exactly does that tell us? I couldn’t say and I not sure anyone really can. But at the very least it strongly suggests that these babies were not physiologically calm when they fell asleep, even though they weren’t crying. Actually, their stress response systems were active.
Now, this does not prove that the methods used in that New Zealand sleep clinic, or any other of the variations in sleep training methods, damages babies. Human beings are resilient and can recover from setbacks – the stress of sleep training is far from the biggest bump in the road a child can encounter. But if someone wants to use sleep training and self-soothing in the same sentence, the most scientifically accurate thing to say would be that ignoring a baby’s cry is a disruption of the social process by which babies learn to self-soothe. Dr. Porges refers to it as “a violation of the child’s biological expectation of safety from an external source.”
Keep in mind that all babies will experience these violations from time to time – not just in the context of sleep training, but for all the myriad reasons that parents can’t necessarily attend to babies immediately: having other children to care for, other responsibilities to attend to, being exhausted or frustrated or ill. Children will also experience similar violations many times in interactions with peers and other people as they grow up. Babies are designed to withstand some of these violations, provided that for the most part parents do respond, not just to a baby’s distress, but also to their other bids for social interaction.
So with respect to sleep training, for me, it’s not a question of absolute right and wrong, it’s about a risk/benefit question for each family. If parents feel that their functioning is greatly compromised, or they are highly stressed by lack of sleep because of an older baby’s night waking (or that their baby is adversely affected by night waking) it’s not our place to second guess them if they want to try sleep training. Highly stressed, unhappy parents aren’t the best thing for babies either. So if a family tries sleep training and it works relatively quickly, and they don’t have to keep doing it over and over again, and the parents understand that the non-responsiveness required in sleep training is an exception to the rule, and if less interrupted nights help the parent(s) be happier and more responsive and sensitive to their babies, then sleep training could be helpful for a family.
But at the same time, if parents want to soothe their babies at night, because they think that’s what their child needs, or they find it easier, or because they’ve tried sleep training and it didn’t work (which happens frequently), sleep training proponents have no right to tell them that they are failing to teach their babies to self-soothe. Science tells us otherwise.