You're not alone if you've ever noticed that while your child seems to talk more freely and at ease at home, at school or in social situations, they suddenly become unusually quiet or mute. This perplexing behavior may be more than shyness, as it is frequently initially noticed in school-age youngsters. It might be a sign of Selective Mutism (SM), an anxiety disease that affects a child's social and academic development but is not as well-known as it should be.