Children and adults with<unk>  are fully capable of speech and understanding language but are completely unable to speak in certain situations, though speech is expected of them. The behaviour may be perceived as shyness or rudeness by others. A child with<unk>  may be completely silent at school for years but speak quite freely or even excessively at home. There is a hierarchical variation among people with this disorder: some people participate fully in activities and appear social but do not speak, others will speak only to peers but not to adults, others will speak to adults when asked questions requiring short answers but never to peers, and still others speak to no one and participate in few, if any, activities presented to them. In a severe form known as "progressive mutism", the disorder progresses until the person with this condition no longer speaks to anyone in any situation, even close family members.<unk>  is by definition characterized by the following: *Consistent failure to speak in specific social situations (in which there is an expectation for speaking, e.g., at school) despite speaking in other situations. *The disturbance interferes with educational or occupational achievement or with social communication. *The duration of the disturbance is at least 1 month (not limited to the first month of school). *The failure to speak is not due to a lack of knowledge of the spoken language required in the social situation. *The disturbance is not better accounted for by a communication disorder (e.g., childhood-onset fluency disorder) and does not occur exclusively in people with autism spectrum disorders or psychotic disorders such as schizophrenia.<unk>  is strongly associated with other anxiety disorders, particularly social anxiety disorder. In fact, the majority of children diagnosed with<unk>  also have social anxiety disorder (100% of participants in two studies and 97% in another). Some researchers therefore speculate that<unk>  may be an avoidance strategy used by a subgroup of children with social anxiety disorder to reduce their distress in social situations. Particularly in young children,<unk>  can sometimes be confused with an autism spectrum disorder, especially if the child acts particularly withdrawn around their diagnostician, which can lead to incorrect diagnosis and treatment. Although autistic people may also be<unk> ly mute, they often display other behaviors—hand flapping, repetitive behaviors, social isolation even among family members (not always answering to name, for example)—that set them apart from a child with<unk> . Some autistic people may be<unk> ly mute due to anxiety in social situations that they do not fully understand. If mutism is entirely due to autism spectrum disorder, it cannot be diagnosed as<unk>  as stated in the last item on the list above. The former name<unk>  indicates a widespread misconception among psychologists that<unk>  mute people choose to be silent in certain situations, while the truth is that they often wish to speak but are unable to do so. To reflect the involuntary nature of this disorder, the name was changed to<unk>  in 1994. The incidence of<unk>  is not certain. Due to the poor understanding of this condition by the general public, many cases are likely undiagnosed. Based on the number of reported cases, the figure is commonly estimated to be 1 in 1000, 0.1%. However, a 2002 study in The Journal of the American Academy of Child and Adolescent Psychiatry estimated the incidence to be 0.71%. Other symptoms Besides lack of speech, other common behaviors and characteristics displayed by<unk> ly mute people, according to Dr. Elisa Shipon-Blum's findings, include: * Shyness, social anxiety, fear of social embarrassment or social isolation and withdrawal * Difficulty maintaining eye contact * Blank expression and reluctance to<unk> ile or incessant<unk> iling * Difficulty expressing feelings, even to family members * Tendency to worry more than most people of the same age * Sensitivity to noise and crowds
Selective mutism
Autism spectrum  disorder  1
Nonverbal autism
Tourettism
Akinetic mutism
Klismaphilia
Taurodontism
Autism spectrum