Compact Basic Knowledge. Why does the girl not speak in kindergarten? Why does the boy remain silent during school? Selectively mute children have the ability to speak, but choose not to use it in un-familiar situations or in communication with certain people. A conversation with these children is often not possible at all or only via gestures or written messages. Nitza Katz-Bernstein elaborates in her book the symp-toms of this dysfunction and explains the diagnostics and different therapies. She takes into consideration thera-peutic elements from various disciplines such as speech therapy, as well as different schools of child and adoles-cent psychotherapy.