Incidence and Prevalence: “Recent prevalence estimates for selective mutism primarily range between 0.47% and 0.76% (Viana et al., 2009), although rates as low as 0.02% (Brown & Lloyd, 1975) and as high as 1.9% (Kumpulainen, Räsänen, Raaska, & Somppi, 1998) have also been reported” (Selective Mutism, 2018).