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Selective Mutism in a 9-to-12-Month-Old: When to Worry
Selective Mutism cannot be identified in a 9-to-12-month-old because it describes a child who can speak in some settings but not others — and spoken language hasn't developed yet at this age. There is nothing to worry about regarding this label now. Instead, observe healthy early communication: babbling, responding to name, gestures and warm back-and-forth. Selective Mutism is usually recognised from around age 3, often when starting nursery. Only a Pinnacle clinician can assess, never an online form.
In this answer 5 sections
If your baby isn't babbling as much as you hoped, it's natural to wonder about Selective Mutism — but here is the reassuring truth about this age.
In short
Selective Mutism cannot meaningfully be identified in a 9-to-12-month-old — it is a label that only makes sense once a child can speak fluently in some settings but consistently does not in others (such as nursery or with unfamiliar people), and that pattern simply cannot exist before spoken language has developed. At your baby's age there is no language for it to be selective about. So this is not something to worry about right now. What is worth gently observing at 9–12 months is your baby's early communication — babbling, eye contact, responding to their name and joyful back-and-forth.
What is actually appropriate to watch at 9–12 months
This is a wonderful window for pre-speech communication. Lovely signs of healthy development include:
- Babbling with varied sounds — "ba-ba", "da-da", "ma-ma" strings
- Responding to their own name by turning or looking
- Sharing attention — looking where you point, following your gaze
- Gesturing — waving, reaching up to be lifted, perhaps pointing
- Warm back-and-forth — smiling, taking turns with sounds and faces
- Showing comfort and connection with familiar carers
These are the true building blocks of later talking. Selective Mutism (ICD-11 6B06) is an anxiety-based condition recognised in children who can already speak — typically noticed around the time a child starts nursery or school, usually from age 3 onwards, not in infancy.
When a check becomes meaningful
If, as your child grows, you notice they speak comfortably at home but fall consistently silent in specific settings (and this lasts beyond the first settling-in month), that is the point to seek a gentle developmental conversation. For now, the kindest step for any niggle is a general developmental check — not a Selective Mutism assessment. Do mention it sooner if your baby isn't babbling at all, has lost sounds or skills, or doesn't respond to sounds.
The Pinnacle way
A clinical AbilityScore® and any diagnosis are formed only at a Pinnacle Blooms Network centre, under qualified clinician care — never from an online form or a checklist. Our team looks at your baby's whole communication picture — hearing, babbling, connection and play — and reassures or guides accordingly. If you'd like peace of mind, our speech therapy and developmental specialists can review early communication, and you can read more about Selective Mutism for the years ahead.
Trusted sources
WHO ICD-11 (6B06, Selective Mutism); American Academy of Pediatrics communication milestones (healthychildren.org); CDC developmental milestone guidance for infants (cdc.gov).
Next step — Rather than worry about a label that doesn't fit this age, book a calm general developmental check for reassurance. Arrange a developmental check with a Pinnacle specialist.
This is general information, not a diagnosis — individual assessment and diagnosis require an appropriately qualified healthcare professional.
CONNECT THE ANSWER TO YOUR CHILD’S DAY
Something to notice. Something to discuss.
What to notice
At 9–12 months, watch for healthy early communication rather than signs of Selective Mutism: varied babbling, responding to their name, sharing attention and following your point, gesturing like waving, and warm back-and-forth play. Seek a general developmental check sooner if your baby isn't babbling at all, loses sounds or skills, or doesn't respond to everyday sounds.
In everyday life
Turn everyday moments into gentle conversations — pause after you speak so your baby can 'reply' with a sound or gesture, copy their babbles back, and name what you both see. This serve-and-return play builds the foundations of talking far more than any worry about labels.
Bring your observations and questions to your child’s professional. Choose activities that suit your child’s comfort, abilities and agreed plan.
Bring your questions to a first visitQuestions families ask
Can a baby under one year have Selective Mutism?
No. Selective Mutism describes a child who can speak in some settings but consistently stays silent in others — which requires spoken language to already be present. A 9-to-12-month-old hasn't developed speech yet, so the label simply doesn't apply at this age.
What should my 9–12-month-old be doing for communication?
Lovely signs include varied babbling like 'ba-ba' and 'da-da', responding to their name, following your gaze or point, gesturing such as waving or reaching, and enjoying warm back-and-forth with familiar people. These are the building blocks of later talking.
When is Selective Mutism usually noticed?
It is most often recognised from around age 3 onwards, frequently when a child starts nursery or school and speaks freely at home but falls silent in those settings for more than the first settling-in month.
When should I get my baby checked?
Seek a general developmental check — not a Selective Mutism assessment — if your baby isn't babbling at all, has lost sounds or skills, or doesn't respond to sounds. A Pinnacle clinician can reassure or guide you.
FOLLOW THE SOURCE
References behind this answer.
- Source referenceWHO ICD-11 — Selective Mutism
- Organisation website · further readingAAP — early communication milestones
- Source referenceCDC — infant developmental milestones
References are supplied with this answer. An organisation homepage offers further reading; it does not establish an independent review of this page.
Content attribution: SETU Consortium · Pinnacle Blooms Network.
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