The essential feature is the persistent failure to speak in specific social situations (e.g., school, with playmates) where speaking is expected, despite speaking in other situations. The disturbance must last for at least 1 month and is not limited to the first month of school (during which many children may be shy and reluctant to speak).

A pattern of continuously refusing to speak in almost all social situations, including school, even though the child understands spoken language and is able to speak.

A consistent failure to speak in specific social situations in which there is an expectation for speaking.