Milestones, and what the ranges really mean

Development charts are presented as timetables and are actually distributions, which is why so much anxiety attaches to a baby who is doing something a month later than a cousin did.

Average versus range

An average age for a skill means half of babies do it later.

Which is why the clinically useful figure is the limit age — the age by which the great majority of children have achieved something, and beyond which assessment is warranted.

Walking is the clearest example: the average is around twelve months, the normal range extends well beyond, and the point at which independent walking warrants review is generally around eighteen months.

A fourteen-month-old who is not walking is ordinary; the internet will tell them otherwise.

Prematurity

An important correction.

Babies born preterm are assessed on corrected age — age from the due date rather than the birth date — generally until around two years.

A baby born two months early who is six months old is developmentally four months old, and expecting otherwise produces unnecessary alarm.

The domains

Development is assessed across several areas, and progress is frequently uneven between them.

Gross motor: head control, rolling, sitting, crawling, standing, walking.

Fine motor and vision: following objects, reaching, transferring between hands, pincer grip.

Hearing, speech and language: startling to sound, babbling, first words, understanding.

Social, emotional and behavioural: smiling, stranger awareness, imitation, play.

A child who is late in one area and typical in others is a different picture from one who is behind across all of them, which is why professionals ask about everything.

Rough guides for the first year

With the caveat that these are approximate.

Around six to eight weeks: social smiling, following a face.

Around three to four months: good head control, reaching for objects, laughing.

Around six months: rolling, sitting with support, babbling, transferring objects.

Around eight to ten months: sitting unsupported, some form of mobility, responding to name, stranger awareness.

Around a year: pulling to stand, cruising, pincer grip, a word or two with meaning, understanding simple instructions, pointing.

Crawling is worth noting as not universal — a proportion of children shuffle on their bottoms or move straight to walking, and skipping crawling is not itself a concern.

The signs that warrant assessment

More useful than the averages.

Not smiling socially by around eight weeks.

No response to sound, or parental concern about hearing at any age, which should always be taken seriously.

Persistent squint beyond around three months, or concern about vision.

Poor head control by around four months.

Not sitting unsupported by around nine months.

Not weight-bearing on legs, or persistent stiffness or floppiness.

A strong hand preference before around eighteen months, which can indicate a problem with the other side.

Not walking by eighteen months.

No words by around eighteen months, or no two-word combinations by around two years.

Not pointing to show interest by around eighteen months.

And, importantly, loss of any skill previously acquired, at any age, which always warrants prompt assessment.

What actually supports development

Unglamorous and free.

Talking to the baby constantly — narrating, naming, responding to their sounds as though they were conversation, which builds the serve-and-return interaction that language development depends on.

Reading together from early on.

Tummy time while awake and supervised, from the early weeks, building up gradually, which supports motor development and reduces flat head.

Floor time and freedom to move, rather than long periods in seats, bouncers and walkers.

Responsive care, which is the strongest single factor in the research on early development.

And limiting screen time in infancy, where guidance in most countries advises against screens for children under around eighteen months to two years other than video calling.

Raising a concern

Parental concern is one of the better predictors in developmental screening and should not be dismissed.

Bring specific examples rather than a general sense.

Ask for a hearing test if there is any doubt about hearing, since it underlies speech and is easily checked.

Ask what the plan is if things do not change by a given point.

And know that early intervention services exist precisely because early support produces better outcomes, which makes asking sooner the right decision even when everything turns out fine.

General information only, not medical advice. Consult your health visitor or a qualified clinician about developmental concerns — parental concern should always be taken seriously.