Research from the Selective Mutism Research Institute (SMRI) indicates many children who present with Selective Mutism also have sensory sensitivities and meet the criteria for Sensory Processing Disorder (SPD). Thus, SPD can be an underlying reason for mute behavior.  

In larger, more crowded environments where multiple stimuli are present (e.g. the classroom setting), a child may have difficulty processing sensory input. As a result, anxiety is produced. As anxiety increases, the child may actually feel fear. In these situations, children with Selective Mutism tend to “shut down,” avoid interacting, freeze, and become mute. They may appear like a “deer-in-headlights.”  

Typical symptoms of children with SM who have sensory challenges present with:  

  • Oversensitivity to being touched by fabrics, hair washing and brushing, hugging, handholding, etc. They often pull out tags from their clothes and prefer elastic band pants compared to buttoned pants.  
  • Tendency to misinterpret touch in the classroom. For example, they will indicate another child pushed them when they were only gently nudged.  
  • Oversensitivity to sounds, lights and/or smells (sounds are the most common sensitivity)  
  • Picky eating tendencies  

Within the classroom, a child with sensory difficulties may demonstrate one or more of the following symptoms:  

  • Social withdrawal/playing alone or not at all  
  • Physical discontent sitting close to or near others 
  • Group activity avoidance  
  • Hesitation in responding (including nonverbally)  
  • ADHD-like symptoms may manifest when in school and in group settings but not in a quieter, calmer and more predictable environment such as at home  

Sensory Processing Disorder may cause a child with SM to misinterpret environmental and social cues. This can lead to inappropriate social responses, frustration, and anxiety. Their inability to effectively communicate reinforces this. Modulating sensory input tends to affect the child’s emotional responses. As a result, many sweet-natured children can also seem quiet, stubborn, or inflexible. 

Children with SM who also have sensory processing difficulties often have emotional regulation challenges as well. Challenging behavioral patterns can manifest such as:  

  • Inflexibility  
  • Procrastination  
  • Stubbornness  
  • Impatience  
  • Crying spells and tantrums  

Experience at the Selective Mutism Anxiety and Related Disorders Research and Treatment Center (SMart Center) indicates sensory processing disorder may or may not lead to learning or academic difficulties. Many children, especially highly intelligent children, can compensate academically and perform quite well. Many focus on their academic skills, often leaving behind the social interaction within school. This tends to be more obvious as the child ages. So, it is not atypical for a child with SM to be timid, have sensory sensitivities, emotional regulation challenges, and/or a subtle speech and language disorder. What is crucial to understand is that many of these symptoms may not exist in a comfortable and predictable setting, such as at home.  

Children are rarely “just mute.” Emphasis needs to be put on the causes and propagating factors of mutism. You cannot simply treat to speak. Understanding the causes as to why a child developed SM is needed to develop an appropriate treatment plan and school based accommodations and interventions. There is no evidence to prove the cause of Selective Mutism is related to abuse, neglect or trauma.