For those of you who aren’t familiar with it, The Wonder Weeks is something of a behavioural prediction for babies. It was developed by the husband-and-wife team of Frans Plloji, a behavioral scientist, and Hetty van de Rijt, an educational psychologist.
What are Wonder Weeks?
The concept goes something like this: Starting at 5-weeks old and continuing through the 20-month mark, babies go through 10 mental development stages or “leaps” as the authors refer to them. These leaps, according to the book, take place at very specific points in a baby’s life.
“Sunny weeks,” during which baby is typically happy and agreeable are followed by “stormy weeks,” during which baby’s fussy and inconsolable due to the neurological development, and then comes the “wonder week” where the new skill or development is mastered and baby goes back to being “sunny” again.
Many parents absolutely swear by this book and its companion app. Some people even claim that it tracks their little one’s development to the day as opposed to the week. Meanwhile, others will tell you that the science it’s built on is flawed, and that what the authors are doing is essentially a form of pediatric astrology, making vague predictions based on norms and averages, and reassuring its followers that good things are perpetually just over the horizon.
Are Wonder Weeks Real?
A couple of things to consider for you data-driven types out there. The 1992 study that The Wonder Weeks is founded on, used a sample size of just 15 participants and relied almost exclusively on questionnaires filled in by the mothers as opposed to direct observation from the researchers. Dr. Plooij’s counter argument for the small sample size, stating that if you find a behavior in two individuals, “then you already have proof that the phenomenon exists and is not due to luck or chance,” doesn’t do much to shore up his credibility.
In the mid 1990s, Dr. Plooij’s Ph.D. student, Dr. Carolina de Weerth, attempted to replicate the findings from the original study with an even smaller sample size of four babies, and failed to reach the same conclusions. Dr. de Weerth claims that Plooij pressured her to find correlations that supported his original research, and when she refused, he attempted to prevent the publication of her findings. (A claim that Plooij denies.) Plooij’s contract with the University of Groningen wasn’t renewed following the incident, and he subsequently left academia altogether.
Suffice it to say, there’s still controversy and debate over its legitimacy. But hey, that’s nothing new when it comes to the world of parenting. Is anything ever written in stone when it comes to babies?
How to Apply Wonder Weeks to My Baby
If parents take comfort in being able to predict when their baby will be cranky, I think that’s just fine. If it helps them through a prolonged period of crying to think, “This is just her developing as she’s supposed to,” then high fives all around. Parents need all the support they can get and I say take your mental health boosts where you can find them.
The potential downside I see is that parents might put too much stock in the accuracy of the book or the app, and develop some unnecessary concerns if things don’t go according to schedule. Because if there’s one thing parents don’t need, it’s unrealistic expectations based on inaccurate research, telling them that their little one has failed to hit a developmental milestone on time.
Wonder Weeks and How it Affects My Baby's Sleep
The big question is, at what point in a baby’s development are you in the clear on working on your baby's sleep? Is it best to wait until after some of these milestones have been cleared? If so, which ones? What can happen if we get started too early or too late?
Let me just state this unequivocally. Outside of a diagnosable health issue, there is absolutely no “wrong time” to teach your baby to sleep well.
Right before a “sunny week,” right at the tail end of a “stormy week,” or smack dab in the middle of a “wonder week,” are all perfect times to get the ball rolling. There’s no developmental milestone, no specific week, no time in a baby’s life that could be considered the wrong time to get them sleeping well.
I’m confident that you’ll never find a pediatrician who’ll contradict me on that statement. It’s not controversial among the scientific community or medical professionals. We’re all in agreement that adequate sleep is essential to the health and well-being of everyone in the family unit, and that teaching your baby some independent sleep skills is safe and effective, whether it’s week five or week fifty five.
There are situations where I’ll tell parents to hold off for a few nights, say if they’re going on holiday within a week or so, and I tend to recommend that they get started on a night when they don’t have to work early the next day. But you should never delay your plans to help your baby develop their sleep skills due to some kind of upcoming milestone. Those are going to keep coming, week after week, and your baby will have a happier time progressing through them if they’re getting the sleep they need.