Wonder Weeks Leap 6

Welcome to the world of categories

Why your baby suddenly wants the red cup, not any cup and how their brain is levelling up again.

Around week 37 (based on due date, not birth date), your baby enters Wonder Weeks Leap 6 and life gets a bit more specific. Suddenly, they’re sorting, comparing, and demanding the exact toy, snack, or spoon they had in mind. And when they don’t get it? Cue the frustration.

This leap is all about understanding categories and it’s one of the reasons babies become more curious, more communicative… and a little more stubborn.

The science: What’s changing in your baby’s brain

Leap 6 marks a shift in your baby’s ability to mentally organise the world. They’re starting to categorise objects, experiences, and people, not just by what they are, but by what they’re like.

This leap is supported by changes in the brain’s prefrontal cortex and temporal lobes, which help with memory, classification, and emotional processing. They’re not just reacting anymore, they’re sorting, predicting, and deciding.

From a neuroscience lens, this is a big jump in cognitive flexibility and executive function foundations.

What this means for your baby

• They may want to play the same game or read the same book over and over.

• They might reject food based on colour or texture.

• You could see stronger preferences, protests, or meltdowns when things don’t match what they expected.

• Sleep might get disrupted again, especially if they’re practicing new physical skills like standing or cruising.

This isn’t defiance. It’s development.

Why this leap feels big for parents

Your baby is becoming more intentional and that includes being more particular. They might protest at bedtime, resist familiar foods, or want to be near you constantly.

It can feel like nothing works the way it used to. But here’s the truth: their brain is reorganising. They’re not “regressing,” they’re rebuilding.

How to support Leap 6

Name the feelings:

“You wanted the red ball. You’re mad it’s not here.”

This helps your baby develop emotional awareness and language for what they’re experiencing.

Sort and match together:

Try stacking cups, nesting bowls, or matching socks.

These activities feed their urge to categorise and feel satisfying in a very big-brain way.

Stick with simple, predictable routines:

Especially at nap and bedtime.

Familiar steps help soothe their now-busier mind.

Let them explore safely:

Offer choices, space to move, and freedom to repeat.

Repetition builds mastery and confidence, even if it’s a bit boring for you.

Offer more patience, not pressure:

They’re not “testing you”, they’re testing ideas.

Some things you will notice this month

✔️ Wanting the same toy, book, or song on repeat

✔️ Protesting transitions (especially sleep

✔️ Rejecting food they ate last week (fabulous...)

✔️ Becoming clingy with one parent

✔️ Waking overnight again

Normal. Normal. Normal. Your baby’s brain is levelling up. This is what Leaps are all about.

Sleep during Leap 6: What helps and what to expect

Leap 6 often disrupts sleep, again. Increased physical mobility (hello, standing in the cot!) and mental leaps can result in delayed settling, shorter naps, and more night waking.

Here’s what helps:

Stick to your wake window sweet spots

Wake windows at this age are usually 2.5–3.5 hours.

Use this:

Last wake-up time + wake window = ideal next nap time

Set a timer to go off 15 minutes before that time to begin the wind-down.

Keep the wind-down calm and consistent

Dim lights, turn on white noise, repeat a short phrase like “Sleep time now.”

Repetition = predictability = safety = sleep.

Pause before you pounce

If they wake after one cycle, wait a few minutes.

Their brain is learning the rhythm of sleep, give them a chance to connect cycles.

Don’t introduce new crutches (unless you’re cool with them)

More cuddles? Yes. A whole new bounce-to-sleep routine? Only if you want to keep it long-term. The trick with Leaps and the sleep disruption that comes with them is to hold the line. Try to maintain the same-ish bedtime, the same-ish approach to sleep etc.

If you’re working on independent sleep

Pick one nap or bedtime to gently support more self-settling.

Stay consistent with your language and signals.

And if they’re standing in the cot? Practice it during the day. Let them learn to sit back down before bedtime.

Common myths during Leap 6

Myth: “They’re being difficult on purpose.”

Truth: They’re learning on purpose. Their reactions are signs of deeper understanding, not manipulation.

Myth: “They should be sleeping through by now.”

Truth: Sleep is still changing and that’s okay. Many babies still wake at night at this age though it isn't biologically necessary anymore. At this age, all Sleep Training Methods are available (they unlock like new players as your baby gets older). If you don't want to sleep train - you don't have to! There are lots of ways you can help your baby learn to self settle and self soothe. Yawn can help you riff out a plan that will work for your bub.

Wonder Weeks meets real life

Not every baby experiences leaps the same way.

Some breeze through Leap 6. Others hit every bump.

But if you notice sleep disruptions, clinginess, or intense preferences, this leap might be why.

Your baby’s brain is building serious processing power. And you? You’re the safe base they come back to every time.

If you could ask an expert one thing…

“How do I support my baby’s new preferences without creating sleep issues?”

Ask Yawn and we’ll help you tailor the “how” to your baby’s age, temperament, and your parenting style.