What happens in Wonder Weeks leap 1, and what does it do to sleep?

The first of the ten leaps from The Wonder Weeks comes around 5 weeks, and it's straight away the most invisible one. Nothing changes about what your baby can do; something changes about what comes in.

What changes in this leap

Kyra sums up leap 1 as the world of sensations. Differences in light, sound and touch get noticed for the first time. What used to be one undivided blur now falls apart into separate impressions.

What you see: more alertness, brighter eyes, and a clearly bigger need for closeness.

Why sleep suffers

Noticing more means processing more, and processing costs energy. That's the link that applies to all ten leaps.

In this first month there's something else too. Your baby can still shut off when it gets too much, and that looks like sleep while it isn't. See the overstimulated baby.

What you do in this leap

Offer less, not more. This isn't the phase to build something up; it's the phase to keep stimulation low.

Keep the wake window short. In the first month that's 45 minutes to an hour and a half, and the time a feed takes simply counts. See newborn wake windows.

Darkening the room works faster than anything in this leap, precisely because light is what really comes in for the first time now. See setting up the nursery.

How you know you're in it

By the three C's: more crying, clinginess, crankiness. Those three together are the sign, and the full approach is in Wonder Weeks and sleep.

The next leap comes around eight weeks and is about patterns: leap 2.