Wondering About the "Wonder Weeks"?
Being a mom today can be so overwhelming and exhausting. There’s so much information out there that when it comes to your children you’re not sure what to believe. New must have baby gadgets, sleep train or not to sleep train, breastfeed or formula feed?
Then you get asked “How is your baby sleeping?” as if there’s a right or wrong answer. You search for answers as to why your child is waking up through the night and think to yourself “It must be teething” “Is there a sleep regression at 6 months?” “They’re in a stormy week”.
If you’re not familiar with the phrase “stormy week” then you’re probably not familiar with the popular book and baby app called The Wonder Weeks. Prior to becoming a sleep consultant I had never heard of the book either until a few different moms had talked about their baby being in a major “leap” which was affecting their sleep.
What is the "Wonder Weeks"?
But just how accurate is this book and what research is the book based on? The Wonder Weeks was developed and written by a husband and wife team; Frans Plloji, a behavioral scientist and Hetty van de Rijt, an educational psychologist.
The overarching concept of the book is that there are 10 major and predictable mental leaps that all babies go through from the age of 5 weeks to 20 months. According to the book, these leaps take place at very specific stages in a baby’s life. They can help parents understand why their baby is extra clingy and cranky during these stages.
Weeks where your baby is typically happy and pleasant are labeled “sunny weeks” or the easy period. These weeks are followed by “stormy weeks” or the fussy period where your baby exhibits “the three C’s”: crying, clinginess and crankiness due to the neurological development they’re going through. Once they master this new leap they go back to the easy period until the next leap.
The information shared in the book gives parents a predictable schedule per say of when their child is going to need extra attention and care. This helps parents better anticipate these changes. The book also gives parents ideas of games to play or specific signs to look for.
That all makes sense, right? 2 million people and counting seem to think so! This book has sold over 2 million copies along with 92K downloads on the App Store. Many parents swear by the accuracy of this app and even claim that it tracks their child’s behaviors and fussiness down to the day.
The Research Behind the Book
Although all of this sounds great, when I looked into the research behind this popular book, the data appears to be lacking and the science is based on vague predictions. The 1992 study1 that The Wonder Weeks is founded on, used a sample size of only 15 mothers and infants and relied heavily on questionnaires from the mothers versus direct observation from researchers. Dr. Plooij backed this small sample size by simply 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”.
A second study was conducted in the mid 1990s by Dr. Plooij’s Ph.D. student, Dr. Carolina de Weerth. She attempted to replicate the findings2 from the original study with an even smaller sample size of four babies, and failed to reach the same conclusions. This is where things start to unravel. 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. Plooij denies this claim altogether. However, after Plooij’s contract with the University of Groningen wasn’t renewed following the incident, he subsequently left academia altogether.
1 Hedwig H.C. Van De Rijt-Plooij PhD & Frans X. Plooij PhD (1992) Infantile regressions: Disorganization and the onset of transition periods
2 Weerth, C. D. (1998). Emotion-related behaviors in infants: a longitudinal study of patterns and variability. s.n.
My Take on the Book
Even today many other scholars and doctors out there feel that there are some holes in the science behind The Wonder Weeks. The truth is that every baby is different, and every baby will experience milestones and “leaps” at different times in their lives. Some babies start rolling as early as 3 months and some babies don’t roll fully until 6 months. For every leap the book references the authors state that it may happen at Y weeks, but could vary between X and Z weeks- often a range of 4 weeks! That’s a pretty big variable for a book that’s supposed to help “predict” your baby’s leaps.
But, there’s no harm in using this book to help you navigate your baby’s rapid development. If it makes you feel better and it seems to be right on, that’s amazing! You may take comfort in knowing why your baby is extra fussy. As parents we need all the accurate information we can get and if you’ve found this book to be accurate then don’t let me stop you from reading and following the app.
I do want to say to be cautious in how much stock you put into the accuracy of this app. If your little one isn’t hitting the milestones or developmental leaps as stated, your baby isn’t a robot, they’re a unique individual. Always talk with your pediatrician if you have specific concerns.
Reach out for Help!
If you’re having sleep trouble with your little one and you’re waiting for the end of their “stormy week” I’m here to tell you that there’s no magical time to make changes. In fact starting sleep training during a tough week can actually help your baby get through the sleep disruption faster.
Sleep is so crucial for our children’s growth and development! No doctor or parent will try to argue that. If you’re holding off in hopes that this too shall pass, it might not. But once your child is an independent sleeper, they’ll be able to sail through those stormy weeks.