What is Selective Mutism?
Selective Mutism is an uncommon and complex childhood anxiety disorder characterized by a child’s inability to speak and communicate effectively in select social settings, such as school. These children speak and communicate in settings where they are comfortable, secure and relaxed.
The term Selective Mutism distinguishes individuals who demonstrate selectivity with whom they speak and are comfortable with, from individuals who speak to no one.
These children understand spoken language and have the ability to speak normally. In typical cases, they speak to their parents and a few selected others. Sometimes, they do not speak to certain individuals in the home. Most are unable to speak in school, and in other major social situations. Generally, most function normally in other ways, learning age-appropriate skills and academics.
These children may respond, or make their needs known, by nodding their heads, pointing, or by remaining expressionless or motionless until someone correctly guesses what they want. The majority of these children express a great desire to speak in all settings, but are simply unable to due to anxiety, fear, shyness and embarrassment.
What are characteristics of Selective Mutism?
Children with Selective Mutism often have tremendous difficulty initiating communication and often hesitate to 
respond, even nonverbally, in specific situations and places.
More than 90% of children with Selective Mutism also have social phobia or social anxiety. These anxiety disorders are quite debilitating and painful to the child. Children and adolescents with Selective Mutism have an actual fear of speaking and of social interactions where there is an expectation to speak and communicate.
Children with Selective Mutism do not speak in specific situations, such as the school, although they do speak in other settings. Often in the settings where they choose not to speak, they communicate by gesturing, pulling, or pushing or, in some instances, by using restricted speech consisting of single words. A small percentage of children with Selective Mutism do not seem to be the least bit shy.
It is common for many children with Selective Mutism to have a blank facial expression and never seem to smile. Many have stiff or awkward body language when in a social setting and seem very uncomfortable or unhappy. Some will turn their heads, chew or twirl their hair, avoid eye contact, or withdraw into a corner or away from the group, seemingly more interested in playing alone.
It is important to realize that the majority of children with Selective Mutism are as normal and are as socially appropriate as any other child when in a comfortable environment. Parents will often comment how boisterous, social, funny, inquisitive, extremely verbal, and even bossy and stubborn these children are at home!
What causes Selective Mutism?
Selective Mutism frequently coexists with general anxiety, and more specifically, social phobia or social anxiety, a more generalized fear of social settings or of performance in those settings.
The cause has not been established, but the majority of children with Selective Mutism have a genetic predisposition to anxiety. In other words, they have inherited a tendency to be anxious. Very often, these children show signs of severe anxiety, such as separation anxiety, frequent tantrums and crying, moodiness, inflexibility, sleep problems, and extreme shyness from infancy on. The anxiety experienced may cause a child to shut down, avoid and withdraw from a situation, or it may cause him/her to act out, have tantrums and manifest negative behaviors.
Selective Mutism is therefore a symptom. Children are rarely 'just mute.' Emphasis needs to be on causes of the mutism.
Some children with Selective Mutism have Sensory Integration Dysfunction which means they have trouble processing specific sensory information and may be sensitive to sounds, lights, and touch, taste and smells. Some children may have specific speech and language problems heightening their anxiety.
Preliminary research indicates that there is a proportion of children with Selective Mutism who come from bilingual/multilingual families, have spent time in a foreign country, and/or have been exposed to another language during their formative language development (ages 2 –4 years old.) These children are usually predisposed to anxiety, but the additional stress of ‘speaking another language’ and being insecure with their skills is enough to cause an increased anxiety level and mutism.
Studies have shown no evidence that the cause of Selective Mutism is related to abuse, neglect or trauma. Children with traumatic mutism usually develop mutism suddenly in ALL situations. This is often due to witnessing some traumatic event, and they are unable to process the event and become mute in all settings.
How is Selective Mutism Diagnosed?
Most children are diagnosed between 3 and 8 years old. In retrospect, it is often noted that these children were temperamentally inhibited and severely anxious in social settings as infants and toddlers, but adults thought they were just ‘very shy.’
The crucial diagnostic element is that the child has the ability to comprehend spoken language and to speak normally, but usually fails to do so in select settings. These children will display reasonably appropriate verbal and interactive skills at home in the presence of a few individuals with whom they feel at ease.
People will often suggest, ‘the child is just shy,’ or ‘they will outgrow their silence.’ Others interpret the Selective Mutism as a means of being oppositional and defiant, manipulative or controlling. Some professionals erroneously view Selective Mutism as a variant of autism or an indication of severe learning disabilities. In fact, a recent study suggests Selective Mutism may be twice as common as autism.
How is Selective Mutism Treated?
Selective Mutism is most frequently a manifestation of anxiety experienced in specific environments and consequently the first goal of treatment is to help children combat their anxiety and to interact in nonverbal ways.
Most successful treatments for Selective Mutism are based on learning and behavior therapies that include reinforcement, modeling, stimulus fading, shaping, or a combination of these strategies. Treatment needs to center on methods to help the child become comfortable and ‘unlearn’ the present 
silent behavior.
Because 20-30 % of children with Selective Mutism have an abnormality with speech and language, a thorough speech and language evaluation is often completed.
Careful attention is given to rule out a Sensory Integration Dysfunction, and an occupational therapy evaluation may be recommended. If warranted by the child’s speech in familiar environments, a speech and language evaluation may be recommended.
Medication may be indicated when behavioral interventions alone have not proven successful and should be prescribed with very careful monitoring of possible side effects by the physician.
If left untreated, the child’s nonverbal communication may go on for many years, becoming more ingrained and reinforced. This may cause a child to ‘look’ and ‘act’ appropriately but communicate nonverbally.
By lowering anxiety, developing self-esteem as well as increasing communication and social confidence within a variety of real world settings, the child with Selective Mutism will develop the necessary coping skills for satisfactory functioning.
Selective Mutism in popular culture:
Music, film, literature and even Disney Channel programming reflects characters demonstrating behaviors consistent with Selective Mutism. Seldom is the disorder named, although often it is described very accurately, as in Paul McCartney’s “She’s Given Up Talking” from the album Driving Rain. The important point to recall in all of these instances is that Selective Mutism is most often a byproduct of a larger childhood anxiety disorder.
This article was condensed from materials developed by the National Association of School Psychologist in conjunction with these additional Selective Mutism references:
http://www.nasponline.org/educators/selectivemutism_ho.pdf
http://anxietynetwork.com/spsm.html
http://www.asha.org/public/speech/disorders/SelectiveMutism.htm
http://www.selectivemutism.org/smg/HelpingOurTeachers.htm
http://www.selectivemutismfoundation.org/about.shtml
http://selectivemutismcenter.org/NYTimes.html
http://www.washingtonpost.com/wp-dyn/content/article/2007/08/26/AR2007082601410.html?hpid=topnews