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Why the Wonder Weeks or Baby Mental Leaps Affect Sleep (Or, Do They?)

Developmental phases, Wonder Weeks, and Mental Leaps - I’m sure you’ve heard of these baby buzzwords, right? But, do you know what they actually mean, and how they can affect your baby’s sleep? And trust me when I say, THEY WILL whether you’re ready for it or not. Click through to learn about the 10 major mental leaps and their correlation to The Wonder Weeks and what you can do to help your little one achieve a good night’s rest. #sleepbabylove #sleeptips #sleepthroughthenight #babysleep #babies #milestones #wonderweeks #babydevelopment

Developmental phases, Wonder Weeks and Baby Mental Leaps.

While I’m sure you’ve heard some of these baby buzzwords before, you may be curious as to what they really mean and, more importantly, what do they have to do with your little ones inability to get a good night’s rest (spoiler: quite a lot, actually).

What are the Wonder Weeks?

The “Wonder Weeks” is a term coined by Dr. Frans Plooij Ph. D. and his wife Dr. Hetty van de, the duo behind—a website that provides resources (books, milestone journals, diaries) to new parents going through fussy baby times. Essentially, similar to what you’ve learned about sleep regressions, babies undergo major developmental changes during the first few years of their lives. What the Wonder Weeks do is organize these changes into 10 predictable, age-linked “mental leaps,” which typically occur during the first 20 months of a baby’s life.

Below are the 10 major mental leaps and their correlating Wonder Weeks:

Mental Leap 1: The World of Changing Sensations (Wonder Week 5)
Mental Leap 2: The World of Patterns (Wonder Week 8)
Mental Leap 3: The World of Smooth Transitions (Wonder Week 12)
Mental Leap 4: The World of Events (Wonder Week 19)
Mental Leap 5: The World of Relationships (Wonder Week 26)
Mental Leap 6: The World of Relationships (Wonder Week 37)
Mental Leap 7: The World of Sequences (Wonder Week 46)
Mental Leap 8: The World of Sequences (Wonder Week 55)
Mental Leap 9: The World of Sequences (Wonder Week 64)
Mental Leap 10: The World of Systems (Wonder Week 75)

NOTE: These weeks are after estimated due date, not actual birthdate

It probably goes without saying that during these major developmental periods, your little one is going to have a rough time keeping a consistent sleep schedule. Just know that the Wonder Weeks were created because fussiness and issues with sleep are so typical.

How Can You Keep Your Sanity If A Wonder Week Affect Sleep

That all said, if your baby is going through a Mental Leap right now, I understand how frustrating and debilitating that can be; how badly you want to help your little one get some shut-eye. I suggest following a few of my favorite tips, to get through Mental Leaps without totally derailing your baby’s sleep training (if they’re older than six months) or having them fall into sleep debt:

  1. Get some help. Whether that’s by hiring a sleep consultant or leaning on your partner or a close friend for support. It’s important that YOU get some sleep too, especially if your little one is being extra fussy, so having someone there to take over when you need rest is vital.
  2. If your baby is dead-set on mastering a new skill, go ahead and help her out! But, make sure her newfound passion isn’t interfering with her nap time. If it is, try and take her away from the situation and get her settled for sleep.
  3. Do a bit of digging on the type of Mental Leap your baby is going through—and the phases he will go through—and try and find activities that will help with that phase. Not only will this help him out and avoid further fussiness, but it will also give you a sense of control since you’ll be better prepared for what’s coming next.

All in all, some parents swear by the accuracy of the Wonder Week. Others love that they had a guide to follow that lays out the good and bad days. But there are also parents with babies who have experienced the exact opposite of what’s predicted in the Wonder Weeks. As one rightfully frustrated mom put it, “His good days always seem to fall within leaps and his bad days can often be in the supposed good patches!”

Here’s Where I Stand With Blaming Everything On a Baby Mental Leap

Personally, I believe Wonder Weeks are a great guide, but that there’s no “one size fits all,” when it comes to babies. That said, it’s nice to get a more detailed idea of the developmental changes going on with your little one—not only because it makes you feel less alone, but it also better prepares you for the changes coming up next. And if you’re prepared for those changes? Then you’re better equipped to help give your baby a good night’s rest.

What do you think about the Wonder Weeks? What worked best for your baby during her development phases? Share in the comments below!

Susie Parker is founder of Sleep Baby Love and a Certified Infant and Child Sleep Consultant through the Family Sleep Institute. When Susie's not ridding the world of sleepless families, she loves spending time with her two girls that have given her a ton of real world sleep experience head on.

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