Five Things We Know About How Babies Grow | Kinedu
The science behind Kinedu · Part 2 of 3

Five things we know about how babies grow.

What 3.5 million children taught us about the first three years.

Why five

Five patterns that help explain development.

Together, these ideas help make sense of how skills connect, when they appear, and why children develop at different paces.

One · Together

Early skills develop together.

Holding their head up gives your baby new ways to look around and interact. It’s one example of how movement, learning, communication, and relationships connect.

PhysicalLifts their head

…and that one skill opens new possibilities:

↓
Cognitive

A new view of the room

Language

More ways to respond to your voice

Social-emotional

More opportunities for face-to-face interaction

The four areas become more distinct as children grow.

This measure shows how closely progress across the four areas is linked. It falls by almost half during the first year, then remains more stable through the ages shown.

0.00.20.40.6 28142435 child age, months 0.49 0.27 more distinct, still linkedclosely linkedhow linked the four areas are (0 to 1)

Kinedu record, 2020–2023 · children observed at consecutive ages between 2 and 35 months · technical name: within-child coupling

Two · In order

Skills build on earlier skills.

Babbling helps lay the groundwork for words. Pulling up to stand helps prepare the way for independent steps. These sequences help us understand what a child may be working toward.

Lifts their head≈ 3 moSits≈ 7 moStands≈ 12 moWalks≈ 13 mo
Lifts their head≈ 3 mo
↓
Sits≈ 7 mo
↓
Stands≈ 12 mo
↓
Walks≈ 13 mo

Expected age: when three in four children have the skill · The order is typical, the timing varies · Kinedu record

From babbling to first words.

As children develop early speech, the assessment shifts its focus from babbling to words.

0%25%50%75%100%0612182430child age, monthsBabbling →First words

Average share of “yes” answers across the milestones in each skill group, by age · Kinedu record, 2020–2023 · shaded band ±1 SD

From first steps to more confident movement.

This skill group includes several milestones, from taking first steps to more advanced movement.

0%25%50%75%100%1218243036child age, monthsWalking

Average share of “yes” answers across the milestones in this skill group, by age · Kinedu record, 2020–2023

Three · Wide

Children reach milestones across a wide range of ages.

For some skills, children reach them within a few months of one another. For others, the range spans well over a year, and it tends to widen as children grow.

Learning to walk8–13 mo · a 5-month rangeDressing and feeding themselves17–39 mo · a 22-month range06121824303642 months
Learning to walk8–13 mo · 5 months wide
Dressing and feeding themselves17–39 mo · 22 months wide
02142 months

An expected age is a reference point, not a deadline.

Four · Windows

A learning window isn’t a countdown.

The chart shows when reports of these skills become more common in our data. These age ranges describe a pattern, not a deadline for an individual child.

06121826Exploring objects1–5 moFirst steps8–13 moFirst words14–25 mo
Exploring objects1–5 mo
First steps8–13 mo
First words14–25 mo
01326
Five · Unpredictable

Today’s assessment doesn’t tell your child’s whole future.

A child’s current skill level tells us little about how quickly they’ll progress next. Where they are today and their pace of development are different things.

An assessment is a photograph, not a prophecy.

Each assessment captures a moment in your child’s development. Checking in again helps you see what has changed.

061218243036your baby’s age, monthsAssessment at 3 monthsat age 2, it says little about where they standAssessment at 2 years3 months later, it still says a lot about where they standChecking in again:a new picture every few months

In this analysis, current skill level explained about 1.5% of the variation in subsequent developmental pace.

See where your baby is today

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References to Stanford, Harvard’s Center on the Developing Child and named researchers are for attribution only and do not imply endorsement of Kinedu. Nothing on this page is medical advice.

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