An overview of Selective Mutism

What is Selective Mutism / how does it manifest itself?

SM is a situational anxiety disorder, which is particularly identified by the following: Children (or adults) with SM are involuntarily mute in given situations. The root cause is anxiety, however younger children may not be able to identify with the term ‘anxiety’ per se. In fact, as well as being mute, children may not to make any sound at all in given situations (such as at school or with extended family members) - including sneezing, coughing, the sound of footsteps, or even flushing the toilet. Additionally, people with SM may also not be able to put pen to paper when writing about themselves. SM can thus affect written language. People with SM may also feel (instinctually) that their own body movements expose their anxieties so they may tend to move rather woodenly or freeze. Thus SM can affect body language. People with SM tend to (instinctually) hide their true emotions, facially, in trigger situations, hence they may tend to either smile incessantly or maintain fixed facial expressions, regardless of how they are truly feeling. Thus SM can affect expressive body language also. All in all, it can be an anxiety disorder affecting all forms of communication.

One can think of SM as an instinctual need to “hide” and to be invisible in given situations, which is very much based on the fight or flight response. There are four potential facets to this response:

  • Fight: Not so common in SM, in trigger situations, due to a fear of scrutiny / drawing attention to one's muteness. However children with SM often save their frustrations for the ones they love, such as their parents, once they get home!
  • Flight: Something people with SM would prefer to do, had they the chance - running off into the distance! For children, having to go to school precludes this, unfortunately - which can make a school environment extraordinarily stressful resulting in the necessity for some children with SM to be home schooled.
  • Freeze: Vocally and physically in trigger situations
  • Fawn: When silent, children and adults with SM generally avoid expressing opinions non-verbally - they may nod to say 'yes', but may shrug rather than shake their heads to say 'no' in order to avoid further questions.

SM is not rare - among young children

The definition of ‘rare’ is arbitrary – anything between 1 in 1,000 to 1 in 1,000,000 or fewer. The incidence of SM reduces with age. 1 in ~150 young children have SM. 1 in ~1000 adolescents have SM. At least 1 in ~2400 young adults with SM. An unknown proportion of older adults exist with SM – into their 40s, 50s, and beyond. I have met an elder with SM. I believe that the incidence of SM is much higher than reported in adults (as someone who is / was? in this category myself.)

Given it is situational, what situations?

The situations in which muteness occurs vary from one person to the next. In many cases school or educational situation is the primary setting. For others it is with all strangers. For others it is people in authority – doctors, dentists, etc. For others it is with extended family members – e.g. grandparents, aunts, and uncles. Less frequently it is with members of one’s own family including parents. In fewest situations, it is with every single person (thus is no longer situational.)

Why does it happen?

SM is multifactorial. SM almost always develops in childhood - ordinarily early childhood or later childhood, if a child is, for instance, being bullied. There is no one reason for children to develop this condition. Many but not all children with SM may have a predisposition to anxiety; they may have other issues such as masked speech difficulties (not uncommon); they may have autism, particularly Asperger’s (not uncommon) - according to Donna Williams, even people with more severe autism report what ‘stops them speaking’ is anxiety; they may have an attachment disorder or they may have experienced early life caregiver separation (due to their own or a parent's hospitalization or illness); or they may have moved from one culture to another (e.g. Japanese children in London).

Other potential explanations: SM is an automatic means to regulate anxiety (Moldan, 2005); to avoid anxiety (Young, Brian, & Beidel, 2012); or mask language or speech deficits (McInnes, Fung, Manassis, Fiksenbaum, & Tannock, 2004; Manassis, et al., 2003); to mask developmental delays (Cleater & Hand, 2001; Kristensen, 2000; Kolvin & Fundudis, 1981); to avoid scrutiny of the observable self (Pujol, et al., 2013; Roth & Heimberg, 2001); to manipulate others, consciously or otherwise, via silence, to create or maintain safety (Anstendig, 1998); as part of an enmeshed relationship with a primary caregiver (Wong, 2010) in which silence mutually serves both the caregiver and child – along the lines of symbiotic mutism (Hayden, 1980); as an automatic reaction to witnessing domestic abuse, along the lines of reactive mutism (Hayden, 1980); as a form of antisocial or oppositional behaviour (Giddan, Ross, Sechler, & Becker, 1997; Wright, Cucearo, Leonhardt, Kendall, & Anderson, 1995); etc. As suggested by the above list of possible functions of SM, SM is a complex, multidimensional behaviour centred upon communication, derived from complex social communicative ‘transactions’ over a long period of time (Cohan, Price, & Stein, 2006). As such, a gene × environment (G × E) interaction (e.g. Nugent, Tyrka, Carpenter, & Price, 2011) may explain SM. Every individual with SM may experience manifold reasons for silence across the duration of the disorder. No one ‘reason’ for muteness may describe the experience of a single sufferer of the condition, multiple factors may be at play all at once.

Common pitfalls:

a) The misperception that SM is always the result of abuse or ill-treatment. Very hollywood, but not correct.
b) The misperception that SM is never compounded by or caused by abuse. Even if SM and ‘abuse’ were as unrelated as having green eyes and experiencing ‘abuse’, statistically speaking there will be and there are children with SM who indeed are abused and whose mutism is compounded by abuse or mistreatment.

The suggestion is that the same proportion of children with SM are abused as those without SM - and there is no statistically significant effect in either direction. If fewer children with SM were abused than in the general population (which I don't believe is the case) then this would raise other questions - i.e. why should children from 'better' backgrounds be more likely to develop a mental health condition relating to communication.

What is it like to experience SM?

Imagine you are alone in a windowless room and there is a very hungry lion, which is not yet aware of you, in the corner of the room. There is no way to escape. What do you do, instinctively? Attack the lion? Or… You will not make a sound to avoid its attention. You will freeze to avoid its attention. You will begin to sweat and have palpitations. You will very definitely want to get out, but there’s no way how… Imagine, instead, it’s a person not a lion or a multitude of people – such as the whole school environment. However your reaction is entirely the same. Unfortunately you are forced to go there and encounter exactly the same thing every single day. At home you will soon develop an aversion to school and will develop panic attacks, even thinking you have to go. You will feel traumatized by your inability to speak and "be like everyone else." Sometimes the person triggering your mutism can be perfectly nice and, in fact, someone you would really, really love to know. The instinctual response of mutism is very often *not personal*.

What are the outcomes of having SM as a child?

From my own research and interactions with other adults with SM and adolescents with SM (in particular, see research findings): other anxiety disorders and depression are very likely outcomes if children do not receive the help they need as children. Depression is almost universal in adults. Anxiety disorders include: agoraphobia, panic disorder, generalized anxiety disorder, social anxiety disorder (develops, almost universally, in teenagers with SM), less commonly cPTSD (because having SM can be traumatic.)


  • Anstendig, K. (1998). Selective Mutism: A review of the treatment literature by modality from 1980-1996. Psychotherapy, 35 (3).
  • Cleater, H., & Hand, L. (2001). Selective mutism: How a successful speech and language assessment really is possible. International Journal of Language and Communication Disorders, 36 (Suppl.) , 126-131.
  • Cohan, S. L., Price, J. M., & Stein, M. B. (2006). Suffering in silence: Why a developmental psychopathology perspective on selective mutism is needed. Journal of Developmental & Behavioural Pediatrics, 27 , 341-355.
  • Giddan, J. J., Ross, G. J., Sechler, L., & Becker, B. R. (1997). Selective mutism in school: multidisciplinary interventions. Language, Speech and Hearing Services in the School, 28 , 127-133.
  • Hayden, T. L. (1980). The Classification of Elective Mutism. J Am Acad Child Adolesc Psychiatry, 19 , 118-133.
  • Kolvin, I., & Fundudis, T. (1981). Electure mute children: Psychological development and background factors. Journal of Child Psychology and Psychiatry, 22 , 219-232.
  • Kristensen, H. (2000). Multiple informants report of emotional and behavioural problems in a nation-wide sample of selective mute children and controls. European Child & Adolescent Psychiatry, 10 (2), 135-142.
  • Manassis, K., Fung, D., Tannock, R., Sloman, L., Fiksenbaum, L., & McInnes, A. (2003). Characterizing selective mutism: is it more than social anxiety? Depression and Anxiety, 18 , 153-161.
  • McInnes, A., Fung, D., Manassis, K., Fiksenbaum, L., & Tannock, R. (2004). Narrative skills in children with selective mutism: An exploratory study. American Journal of Speech-Language Pathology, 13 , 304-315.
  • Moldan, M. B. (2005). Selective mutism and self-regulation. Clinical Social Work Journal, 33 (3), 291-307.
  • Nugent, N. R., Tyrka, A. R., Carpenter, L. L., & Price, L. H. (2011). Gene-environment interactions: early life stress and risk for depressive and anxiety disorders. Psychopharmacology (Berl), 214 (1), 175-196.
  • Pujol, J., Giménez, M., Ortiz, H., Soriano-Mas, C., López-Solà, M., Farré, M., . . . Martín-Santos, R. (2013). Neural response to the observable self in social anxiety disorder. Psychological Medicine, 43 , 721-731.
  • Roth, D. A., & Heimberg, R. G. (2001). Cognitive-behavioural models of social anxiety disorder. Psychiatric Clinics of North America, 24 , 753-771.
  • Wong, P. (2010). Selective Mutism: A review of etiology, comorbities and treatment. Psychiatry, 7 (3), 23-31.
  • Wright, H., Cucearo, M. L., Leonhardt, T. V., Kendall, D. F., & Anderson, J. H. (1995). Case Study: Fluoxetine in the multimodal treatment of a preschool child with selective mutism. Journal of the American Academy of Child and Adolescent Psychiatry, 34 (7), 857-862.
  • Young, B., Brian, B., & Beidel, D. C. (2012). Evaluation of Children with Selective Mutism and Social Phobia: A comparison of Psychological and Psychophysiological Arousal. Journal of Behavioural Modification (407).


You may also be interested in the following books on Selective Mutism

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