The purpose of this study was to gain phenomenological information about Selective Mutism (SM) in the following areas: (a) mute and variant talking patterns that occur prior to the identification of SM and/or which occur as conditions within the SM syndrome, (b) events that precipitate SM, (c) biological vulnerabilities for SM in terms of anxiety and temperament variables, (d) characteristics associated with SM, (e) other problems experienced with SM, and (f) school and social competencies. A comprehensive survey included 153 participants who had experience with SM, 135 of whom were under 18 years of age and 18 of whom were 18 years of age or older. Evidence supported three theoretical assumptions. First, results supported the existence of variant talking behaviors (talking with less frequency, volume, and spontaneity than usual), in addition to mutism, prior to the identification of SM and as part of the SM syndrome. Setting (home, school, community) affected the rate of occurrence for mute and variant talking behaviors, with these behaviors occurring primarily in the school and community settings. Second, evidence supported a link between SM and social anxiety or phobia. Participants who no longer had SM continued to experience problems conversing and discomfort in social situations. Internalized problems were significantly greater than Externalized problems on the Child Behavior Checklist (CBCL) and Youth Self-Report (YSR). Item analysis of these two scales also revealed anxiety symptoms for children with SM. Third, we found support of the notion that persons with SM may have characteristics similar to behaviorally inhibited or slow-to-warm children, suggesting a potential link between temperament and SM. As infants or toddlers, participants typically did not respond well to new stimuli. They also had difficulty handling transition or change. Implications for future research are presented.