What happens in Wonder Weeks leap 5, and why does my baby suddenly cry at bedtime?
Kyra Hendrix, certified Gentle Sleep Coach® trained in the Kim West method · updated November 8, 2026
For babies around 6 months old
Wonder weeks leap 5 comes around twenty-six weeks and is about relationships: your baby sees links between people and objects and gets more interested in play and interaction. This is also the leap in which separation anxiety can show up, and that affects sleep. Always respond with extra closeness and security.
In this leap, something changes about putting your baby to bed itself, and it isn't because you're doing anything differently.
What changes in this leap
Leap 5 is about understanding relationships. Your baby sees links between people and objects: things belong together, and people belong with things. You see more interest in play and in interaction.
And something comes out of that which you notice in the evening.
Why bedtime suddenly gets harder
If you understand that people and things belong together, you also understand that someone is gone when they leave. That's the beginning of separation anxiety.
For a baby, that's big. Walking out of the room isn't "away for a moment", it's gone. Hence the crying the moment you close the door, while the bedtime ritual went just like always.
No technique helps here, only closeness: stay sitting a little longer, give extra comfort, show that you come back. See also milestones and poor sleep.
What you do in this leap
Respond to it, and don't be afraid you're teaching anything with it. That isn't possible: whether you can spoil a baby.
What does help is predictability. The same ritual, the same order, the same words when you leave. See the bedtime routine.
And watch the wake windows, because overtiredness makes separation anxiety heavier instead of lighter. Around this age, that's about two hours between naps: wake windows from 6 to 8 months.
How you know you're in it
By the three C's: more crying, clinginess, crankiness. The full approach is in Wonder Weeks and sleep.
Before this came leap 4. Around thirty-seven weeks leap 6 follows, in which that same separation anxiety gets stronger.
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