Read

An assessment is a photograph, not a prophecy

A milestone checklist or screener tells you something real about your child today. How much it says about later, what it can’t say at all, and how to read one without treating it as a verdict.

Short answer: A developmental assessment tells you where a child stands today compared with children her age. It gives useful odds about later standing, especially over short periods, but it fades fast in infancy. It says almost nothing about how quickly she will progress next: in Kinedu data, starting standing explains about 1.5% of later pace. It is not a diagnosis.

What can a developmental assessment tell you?

At Kinedu, parents answer plain questions about what their child does at home, such as whether she holds her head up or points at things she wants. Together, the answers show where she stands next to children her age: what she is working on, what usually follows, and what might be worth raising at a checkup. The book’s parent’s guide to the Kinedu Report sums up its limits in one line: “An assessment is a photograph, not a prophecy.”

How well does a result today predict later development?

We took a single early assessment from a very large number of children and asked how much it tells you about where they stand later. It depends on how old the child was and how far ahead you look.

How much one assessment tells you about later standing (Kinedu data)
Age at assessmentLooking aheadCorrelation
3 to 4 months3 monthsr = 0.42
3 to 4 months2 yearsr = 0.23
24 to 25 months3 monthsr = 0.61 (about 37% of later variation)
Same assessment, predicting pace of changeSubsequent changer = 0.12 (about 1.5% of variation)

These are Kinedu data, from an internal analysis of roughly 3.5 million children that has not yet been published with peer review. They describe odds across a population, not what will happen to any one child.

Two things stand out. An early reading ages quickly: in the first months the areas of development move almost as one, then pull apart after the first year, so a baby’s score says much less about her at age one (see Everything is everything). And the last row: where a child stands today tells you very little about how fast she will move from here. Children who start behind don’t, on average, progress more slowly.

What can’t an assessment tell you?

It can’t tell you what caused anything, because the records show what a child did, not what anyone did with her. It can’t tell you something is wrong: it is a surveillance tool that flags things worth watching, not a diagnosis. And part of any parent-reported score reflects how the caregiver tends to answer rather than the child herself.

When should a result lead to a conversation with the pediatrician?

Treat one reading as a single frame; what matters is a pattern over time. Talk to your pediatrician if an expected skill still hasn’t shown up after several months, if your child stops doing something she used to do, if she doesn’t turn to her name or look for your face, or if a quiet worry has stayed with you. Asking early is sensible, not anxious.

The better question isn’t where she ranks, but what she is ready for now: read Is my child behind? or try the Ready for now tool. Methods and limits are on the Kinedu Report page. The full “why” behind these numbers is in Chapter 2 of Big Bang Baby. You can read the Introduction free.

Sources