Chorevia

Day 125 of 300 · Week 17

I can make things happen

Last reviewed · 3 min read · 13 sources · Plain-text version

Around 4 months babies discover that a kick shakes the mat and a wave rattles the rattle. What that memory looks like in the lab, and a safe way to stage the concert.

A Latino father kneels at the feet of his seventeen-week-old lying on a play mat, holding a soft crinkly drum against the baby's soles, the baby's legs mid-kick and face lit with surprise.

Somewhere around now, your baby works out that they can make things happen. Today you put an instrument where their feet are.

Heart

Around 4 months, babies start figuring out that they can make things happen: a kick shakes the crib, a wave rattles the rattle. Sometime after 4 months, they also begin to learn that things still exist when they're out of sight (AAP). Rattles rattle, kicks shake the mat, and smiles bring you closer; that is the lesson of the month, and it needs no teacher beyond you (AAP).

Head

The classic experiment was built on kicking. Three-month-olds learned that kicking moved a crib mobile. They usually forgot after about 8 days, but a brief reminder the day before the test let them remember for 2 to 4 weeks (Rovee-Collier et al., 1980). Repeated games stick; your baby is learning what to expect. What they know about hidden things is harder to pin down: 5-month-olds in the famous "drawbridge" study looked longer at a screen that seemed to rotate through a hidden box (Baillargeon et al., 1985), but a later study found babies looked longer at the bigger rotation even with no box at all (Rivera et al., 1999). Play the games for the fun of them.

Body

The AAP's example is a kick that shakes the crib. Yours happens on the floor, with you holding the instrument. Never tie anything to your baby's arms or legs, and nothing goes in the crib: a firm, flat surface with only a fitted sheet, no toys, no positioners (Moon, AAP). The same goes for anything dangling: use cordless blinds or keep cords out of reach (AAP).

Try today

  1. The baby on their back on the mat, both feet pressed into a cloth drum the father holds low, the mother beside them clapping, an older sister watching from the sofa.

    The crib-kick concert

    Time: 2 to 5 minutes · Kick and see in the guide

    1. Lay your baby on their back on the floor mat and hold a crinkly toy or a soft drum where their feet can reach it.

    2. When a kick lands and it makes a sound, react with delight.

    3. Hold it still and wait. See if they kick again on purpose.

    4. Swap the instrument: a rattle held against the soles, a square of crinkly fabric, your own hands clapping when a foot hits.

    5. Do it again tomorrow; a reminder is what keeps the memory (Rovee-Collier et al., 1980).

    Make it work:

    The toy stays in your hand, never tied to them, and never left in the crib (Moon, AAP).

Watch for

  • Normal: kicks strong enough to scoot across the mat. Never leave your baby alone on a changing table, even for a moment, even strapped in (AAP), and call your pediatrician right away for any head injury, including a fall from a bed, couch, or changing table (AAP).
  • Normal: feeds cut short by looking around; babies get far more aware of the world around 4 to 6 months, and a phone, a pet, or a voice can pull them off mid-feed (Australian Breastfeeding Association). Call your pediatrician right away for signs of dehydration: no wet diaper in more than 8 hours, a very dry mouth, or no tears (AAP).
  • Go to the ER now if your baby vomits green (bile) or blood (AAP).

For you

The mother in bed in a dark room pulling the covers up, lamp off, a baby monitor glowing on the nightstand beside a glass of water, a bare bassinet visible by the bed.

One cause and effect for you. New mothers' sleep is more broken than short, and it gets less fragmented over the first 4 months (Montgomery-Downs et al., 2010), so a long stretch is finally something that can exist. The AAP's tip for tired parents is to bank sleep: nap when your baby naps, and go to bed right after the last feed (Moon, AAP). Tonight, run the experiment. Last feed, lights out, no scrolling. See what the kick does.

If you're the partner: the first waking is yours tonight, so her stretch stays whole.

Sources

This guide is general education that summarizes published research and guidance from groups like the American Academy of Pediatrics, the CDC, and the WHO. It isn’t medical advice, and every child develops on their own timeline. Your pediatrician knows your child; if something feels wrong, call them. In an emergency, call 911.

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