Why Is My Second Child Talking Later Than My First?

By Julia Taylor, B.App.Sc. (Sp.Path.), M.Hlth.Sc., CPSP 5 min read

You remember your firstborn chattering away at this age — and here's the second child, months behind that remembered timeline, perfectly happy to let a big sibling do all the talking. Is the older child ‘stealing’ the younger one's words? Here's what the research actually shows, and the one practical fix that matters.

What the research says about siblings

There is a real, documented association: in one population study summarized by ASHA, children with late language emergence were less likely to be only children. ASHA notes this may reflect how parental time and resources get divided in busier households (ASHA, n.d.).

But an association is not a cause, and it is not a prophecy. The same research summary lists many other factors that travel with late talking — family history, hearing, early comprehension, socioeconomic circumstances — so ‘has an older sibling’ on its own explains very little about any one child (ASHA, n.d.). Plenty of younger siblings talk early; plenty of only children talk late.

Beware the big-sibling yardstick

Here's the trap: parents of second children usually aren't comparing against milestones — they're comparing against a rose-tinted memory of the first child. Memory inflates. The fair test is the actual checklist: pointing and a first word or two around the first birthday, at least three words besides ‘mama’ and ‘dada’ by 18 months, two-word combinations by age two (CDC, 2026a; CDC, 2026b; CDC, 2026c). If your second child is meeting those, they're not ‘behind’ — they're just not their sibling.

If they're genuinely missing milestones, the response is the same as for any child: a friendly screening and a hearing check, sooner rather than later. Birth order is never a diagnosis, in either direction.

Protecting the little one’s talking turns

The genuinely useful insight from the sibling research is about airtime. In a busy house, the fastest talker wins the conversational turn — and that’s rarely the toddler. You don’t need to sideline the older child; you need to referee a little.

Carve out ten daily minutes of one-on-one play with the younger child — a word kit like the MORE Kit makes it effortless to fill.
When big sibling answers for little sibling (‘She wants the red one!’), thank them, then hand the turn back: ‘Let’s hear her tell us.’
Make the older child a teammate: they’re brilliant at repetitive games, songs, and pretend play — all first-class language fuel.
Keep shared routines rich — books at bedtime, songs in the car, chatting through meals — with a deliberate pause for the youngest voice.

The takeaway

Younger siblings are statistically a bit more likely to be late talkers — probably an airtime issue, not a curse — and the fix is protecting daily one-on-one talking turns. Measure your second child against the milestones, not against your first child's highlight reel, and check early if the checklist says so.

Sources & further reading

American Speech-Language-Hearing Association. (n.d.). Late language emergence (Practice Portal). https://www.asha.org/practice-portal/clinical-topics/late-language-emergence/
Centers for Disease Control and Prevention. (2026a). Milestones by 1 year. https://www.cdc.gov/ncbddd/actearly/milestones/milestones-1yr.html
Centers for Disease Control and Prevention. (2026b). Milestones by 18 months. https://www.cdc.gov/ncbddd/actearly/milestones/milestones-18mo.html
Centers for Disease Control and Prevention. (2026c). Milestones by 2 years. https://www.cdc.gov/ncbddd/actearly/milestones/milestones-2yr.html

A friendly note (and the fine print)

This article is general educational information only. It is not speech therapy, therapeutic advice, an assessment, a diagnosis, or a substitute for individualized professional care, and reading it does not create a therapist–client relationship. Every child is different — if you have any concerns about your child’s speech, language, hearing or development, please consult your own certified speech-language pathologist, pediatrician or family health professional, who can advise you about your individual child. See when to talk to a professional for how to find one.

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