A case-control study of EAS child and parental temperaments in selectively mute children with and without a co-morbid communication disorder.

Clarification of sub-groups of children with selective mutism (SM) may enhance the understanding of symptom development. The present case-control study compares temperament characteristics applying EAS temperament survey in SM children with a co-morbid communication disorder (CoD), SM children without CoD and matched controls. Temperament characteristics in the parents are compared as well. The results show that SM children with CoD are characterized by more emotional stability and higher sociability than SM children without CoD. The parents of the SM children with CoD did not differ in temperament characteristics from the control parents. The parents of the SM children without CoD differed from the controls on the Distress, Fear and Activity scales. The study suggests different familial transmission in the two sub-groups of children with SM.