What Is Selective Mutism? A Parent's Plain-English Guide

If I had a pound for every time someone said "oh, she's just shy" about my daughter, I would have filled her Junior ISA by now.

For a long time, I thought the same thing. She was born during Covid, her early socialisation was almost non-existent, so of course she was shy. But it was a friend of our childminder who ran a local SEN support group who first spotted what was actually going on, followed closely by my Ed Psych sister. Initially, having never heard of it, I sat there wondering what is selective mutism?

It took me a long time to piece things together from different websites and different sources, so here is my own plain English explanation, for parents who are where I was. It's also often referred to as situational mutism which is fast becoming a preferred term.

What is selective mutism?

Selective mutism (sometimes called situational mutism) is a social anxiety disorder that results in a phobia of speaking in certain situations. That's the clearest way I can put it. Just as some people are afraid of heights or spiders or small spaces, a child with this condition experiences a genuine fear-based freeze response around speaking in certain contexts.

SMIRA, the UK's leading SM charity, describe it as an anxiety-based condition that usually begins in early childhood, where a child speaks freely in some situations but remains consistently silent in others. That blank, frozen look people sometimes mistake for rudeness or indifference is the freeze response. Their nervous system is in full alarm, and speech becomes physically impossible.

If you want to understand what the symptoms look like in practice, I've written a separate post on that.

What causes selective mutism?

I've come to realise that supporting this complex condition requires a multi-faceted approach, one that with my corporate background I can't help but call 'top down and bottom up' — but more medical folks would probably say holistic!

There isn't a single cause. It's usually a combination of factors, and every child's picture looks a bit different. Here are the ones worth understanding.

Anxiety — the biggest one by far. Anxiety is at the root of this and this is why selective mutism therapy often isn't straightforward and many speech and language therapists don't in fact specialise in it, because the child doesn't always present with speech issues, and can't just rock up to a SALT appointment and speak on demand.

Temperament — many children with SM were cautious from very early on. Slow to warm up, wary around new people, watchful in unfamiliar settings. Researchers call it behavioural inhibition and it isn't the same as shyness — it's more like a neurological predisposition to freeze in novel situations. My psychotherapist friend Megan talks about how these types of humans are the ones that probably kept our caveman ancestors alive, watching for threats on the horizon.

Family patterns — SM often runs in families. Not always, but often enough that it's worth a quiet look at your own history. Was anyone the quiet one at school? Did anyone in the family struggle with social anxiety? Recognising that pattern can actually be reassuring — it helps explain the why. I personally couldn't relate but my mum has talked openly about being painfully shy as a child and that was before we really had a language for social anxiety.

Neurodivergence — not always, but sometimes this can be a factor. Selective mutism and autism can overlap, although they are separate conditions.

Environmental triggers — starting school, a house move, a family trauma, a new sibling, or in our case, being born into a pandemic was potentially part of it. These don't cause SM on their own, but they can activate it in a child who was already predisposed. It's the thing that tips it from quiet temperament into a freeze that then means the child needs help.

Retained reflexes — this is quite a new area of research and I can't state a clinical view here, only that I recognise in my daughter the fear paralysis reflex in some situations and I am personally exploring this route alongside all of the talking interventions we do.

Auditory issues — also rare and not spoken about much but I spoke to a specialist OT on the phone the other week who had a child come in for Auditory Integration Therapy recently with SM and started talking after the course of treatment — amazing!

A note on bilingualism — a bilingual child going through a silent period in their second language is not necessarily the same thing. That's a normal part of language development and usually resolves on its own. If your child is bilingual and struggling, it's best to find Anna Biavati's clinic as I believe she is the global expert in this space and she has an utterly lovely PA who can help you explore if her support packages are right for you.

Selective mutism treatment and specialist support in the UK

If you're looking for professional input, the assessment journey varies depending on where you live. Many children are referred to speech and language therapists who don't specialise in SM, and families can spend a long time going in circles.

If you have roughly £1,000+ there are two private SM specialists in the UK I'd point anyone towards:

Confident Children — led by Lucy Nathanson, who is also the author of Why Alice Doesn't Talk at School (a book I'd recommend to anyone with a child in primary school — Phoebe's teacher read it to her class). Confident Children offer online sessions and have worked with families internationally.

Anna Biavati — a speech and language therapist specialising in SM, offering remote support for parents and professionals. Mentioned above because she is a specialist on bilingualism too and I like that she incorporates the anxiety piece into the picture.

Both are good. Both are £1,000+ to engage properly, which is the reality most families face.

So if you want the reassurance of a person to talk to, great. But I wanted something perfectly tailored to our situation, and I had already done so much to educate myself so I built SM Pocket Coach specifically to fill that gap. It's an AI coaching tool trained on the same therapy frameworks these specialists use, designed to help you understand your child's situation and work through strategies without needing to afford a private SALT or sit on an NHS waiting list for years.

If you think your child might have SM, start with my plain-English guide to the symptoms. And if you're wondering about the overlap with autism, that's its own post.