Selective mutism is a condition in which there is a persistent failure of a child to speak in one or more specific social situation particularly school setting. A child with selective mutism may be completely silent or near silent.  Children with this condition can speak fluently when they are not in a socially anxiety-provoking situation.  Some children with this condition may communicate through nonverbal gestures. This condition is believed to be an expression of social phobia since it involves failure to speak in certain social situations. This condition is more commonly seen in girls than in boys. Also, younger children are more susceptible to this condition than the older ones. The prevalence of this condition varies with age.  In a survey, it was found that 90% children with this condition also met the diagnostic criteria for social phobia.  It is thought this condition is not a distinct disorder but is a subtype of social phobia. An interesting finding suggests that children with this condition may have deficits in auditory processing. There is also another phenomenon called traumatic mutism in which a child is predisposed to selective mutism after early emotional or physical trauma. The age of onset can range from 4 to 8 years. Also, children with this condition may have some symptoms of separation anxiety disorder.  Since social anxiety is present in almost in every child with this condition, temper tantrums and oppositional behaviours may also occur.  Since these children are shy they are susceptible to the development of depression.  These children may have difficulty forming social relationships.

A study investigated parental problems, parenting attitude and emotional and behavioural problems in children with selective mutism. This study involved 26 children with selective mutism and 32 healthy controls and parents of all children. It was found that children with selective mutism had high scores on a variety of emotional and behavioural problems. They displayed aggressive and delinquent behaviours among a subsample of children. Significant differences also existed in the groups only in paternal psychopathology which included anxiety and depression. There were no differences with respect to maternal psychopathology. Another important result is that the severity of emotional and behavioural problems of children with selective mutism was correlated with maternal psychopathology and not with paternal psychopathology.