Other symptoms
Besides lack of speech, other common behaviors and characteristics displayed by selectively mute people, according to Dr. Elisa Shipon-Blums findings, include:
Shyness, social anxiety, fear of social embarrassment or social isolation and withdrawal
Difficulty maintaining eye contact
Blank expression and reluctance to smile or incessant smiling
Difficulty expressing feelings, even to family members
Tendency to worry more than most people of the same age
Sensitivity to noise and crowdsOn the flip side, there are some positive traits observed in many cases:

Above average intelligence, inquisitiveness, or perception
A strong sense of right and wrong
Creativity
Love for the arts
Empathy
Sensitivity for other people

Causes
Selective mutism (SM) is an umbrella term for the condition of otherwise well-developed children or adults who cannot speak or communicate under certain settings. The exact causes that affect each person may be different and yet unknown. There have been attempts to categorize, but there are no definitive answers yet due to the under-diagnosis and small/biased sample sizes. Many people are not diagnosed until late in childhood only because they do not speak at school and therefore fail to accomplish assignments requiring public speaking. Their involuntary silence makes the condition harder to understand or test. Parents often are unaware of the condition since the children may be functioning well at home. Teachers and pediatricians also sometimes mistake it for severe shyness or common stage fright.Most children and adults with selective mutism are hypothesized to have an inherited predisposition to anxiety. They often have inhibited temperaments, which is hypothesized to be the result of over-excitability of the area of the brain called the amygdala.
Post-secondary accommodations are also available for people with disabilities.Under another law, Section 504 of the Rehabilitation Act of 1973, public school districts are required to provide a free, appropriate public education to every "qualified handicapped person" residing within their jurisdiction. If the child is found to have impairments that substantially limit a major life activity (in this case, learning), the education agency has to decide what related aids or services are required to provide equal access to the learning environment.Social Communication Anxiety Treatment (S-CAT) is a common treatment approach by professionals and has proven to be successful. S-CAT integrates components of behavioral-therapy, cognitive-behavioral therapy (CBT), and an insight-oriented approach to increase social communication and promote social confidence. Tactics such as systemic desensitization, modeling, fading, and positive reinforcement enable individuals to develop social engagement skills and begin to progress communicatively in a step-by-step manner. There are many treatment plans that exist and it is recommended for families to do thorough research before deciding on their treatment approach. Self-modeling
An affected child is brought into the classroom or the environment where the child will not speak and is videotaped. First, the teacher or another adult prompts the child with questions that likely will not be answered. A parent, or someone the child feels comfortable speaking to, then replaces the prompter and asks the child the same questions, this time eliciting a verbal response. The two videos of the conversations are then edited together to show the child directly answering the questions posed by the teacher or other adult.