Year 2: Mental Leaps, Growth Spurts, and Sleep

We now know that the periods during which babies are reportedly “difficult,” characterized by clingy-ness, crankiness, and crying, are tell-tale signs of a major leap in their mental development.

All babies undergo these fussy phases at around the same time. The clingy periods come at 5, 8, 12, 19, 26, 37, 46, 55, 64 and 75 weeks. The onsets may vary by a week or two, but you can be sure of their occurrence.

Calm, easy-going babies react to these mental leaps in the same way as temperamental babies do. Dealing with these mental leaps will be harder for moms who’s babies already require more attention. Because these children have a greater need for mommy, they will inevitably have more conflict.

“Wonder Weeks,” as explained in the infant development book The Wonder Weeks by doctors Hetty Van de Rijt and Frans Plooij, are a critical period of development during which the way your baby perceives the world changes drastically.

For example in week 26, your baby will start to perceive distance. As you walk away, Baby will now become aware of the increasing separation and may yell out or panic because the increasing distance is not only confusing but scary.

As you can imagine, sensitive babies need extra reassurance and may become clingy as the last thing they want is mommy to be far away.

Baby gains a new perception with each mental leap. This new potential enables them to perceive new things. All these things were present before the leap but baby’s brain did not know how to process it yet.

After mental leaps, baby’s whole world changes as they notice all these new things.

mental leaps
Wonder week 64, mental leap 9
  • Principles

Baby can now change the programs he’s learned and he loves to experiment with this. Baby will vary the programs and endlessly study the consequences.

As he does this he starts to become more skillful with language, imitate others, role play what happens in daily life, think ahead, and practice emotions. You will also notice that baby starts to demand a vote and can distinguish between mine and yours.

Baby will start to experiment with yes and no and negotiate and bargain and joke and even try to get on Mom’s good side to see what happens. They want to help in the household and like to do things together. Baby will also start to experiment with “thoughtless” and “careful. ”

Week 65 or 15 months old to week 74 or 17 months

Baby will be sharpening the skills they’ve learned. Baby will be sleeping well and eating just fine as they learn more skills.

mental leaps
Wonder week 75 mental leap 10
  • Systems

75 weeks after your due date baby will attain the ability to handle systems.

If you recall, baby previously learned about principles and they can now adjust their principles to changing circumstances. Baby now realizes he can choose how to be; that is, careful, patient, and honest or the exact opposite.

Baby is basically developing a conscience by upholding certain values. You cannot spoil a baby, but you can certainly spoil a toddler. You shape the future of your child’s behavior.

Think of it like a store with different departments. When baby makes a mental leap, they can now enter a new department for the first time. Once in that department, they get to choose a product/skill to practice. What and how he chooses is what makes your baby unique.

week 78 or 18 months

Growth spurt!

This endless ball of energy will test you from the moment you wake up till they finally fall asleep. You will now start to notice that your baby has now become a little boy or girl. Your child now talks proficiently and loves mobility. Toddlers love to show off what they’ve learned. They love to push and pull and balls provide endless fascination.

The playpen walls will feel too confining and they will take every opportunity they have to escape. Few activities will gather their attention more than rearranging your house. While it may be inconvenient that baby wants to get into all the drawers and look and touch everything, they are simply trying to learn. Keep your owner’s manuals close because all buttons will be pushed, yours and your stereos!

Understanding what’s happening with your baby through these mental leaps will make it much easier for you to cope with the sleepless nights and crankiness during the day.


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