Every parent has read a chart and felt the floor tilt. It is worth knowing that those charts describe averages across large populations, that the normal range around each one is wide, and that a single missed item is weak evidence of anything at all.
What is worth attending to is different, and it is mostly about pattern.
Four patterns worth acting on
1. Losing a skill
A child who had words and stops using them, or who was socially responsive and becomes less so, is showing something qualitatively different from being late. Regression is the one item on this page that is worth a prompt clinical appointment rather than a watchful month. That is true whatever else is going on.
2. Several areas at once
Late walking on its own is very often nothing. Late walking alongside late babbling, little pointing and little response to name is a pattern, and a pattern is worth looking at properly. It is the combination that carries the information.
3. A widening gap
Being six months behind at eighteen months and six months behind at three years is a child keeping pace from a later start. Being six months behind at eighteen months and eighteen months behind at three is a different trajectory, and trajectory matters more than position.
4. It is affecting the day
Independent of any chart: if your child cannot join in what other children their age are joining in, cannot make themselves understood, or is distressed daily by ordinary demands, that is worth addressing whether or not anything is technically late.
What tends not to be a signal on its own
- Walking late in an otherwise sociable, communicative child
- Being a late talker with a family history of late talkers, where everything else is on track
- Bottom shuffling instead of crawling
- Being noticeably behind a sibling — siblings vary enormously
- Growing up with two or three languages, which does not cause delay
The two-week notebook
Before you contact anybody, spend two weeks writing down what you actually see. Not conclusions — observations, with the time of day, who was there, what came immediately before, and what happened next.
This is the single most useful thing you can bring to a first appointment, and it costs nothing. "He does not listen" is a conclusion. "He does not respond to his name when the television is on, but does in a quiet room" is an observation, and it is worth ten of the first kind to a clinician.
Who to ask first
- A hearing test. Always. It is quick, cheap, and it explains a surprising amount.
- Your paediatrician, with the notebook. Ask them specifically what they would want to see in three months, and what would concern them.
- The nursery or school, if your child is in one. They see forty children of the same age and their sense of what is unusual is genuinely calibrated.
The honest position on waiting
You will be told both that early intervention is critical and that many children catch up on their own. Both are true, which is why the advice feels contradictory.
The way through it is that the early actions worth taking are cheap, reversible and useful either way. A hearing test, two weeks of notes and one professional opinion are not a commitment to a programme. They are how you find out whether you need one — and they cost very little if the answer turns out to be no.