Speaking rates, response time latencies, and interrupting behaviors of young stutterers, nonstutterers, and their mothers.

The purpose of this study was to investigate the speaking rates, interrupting behaviors, and response time latencies (RTL) produced by stuttering and nonstuttering children and their mothers, and the relationship these three paralinguistic behaviors have to children's speech disfluencies. Subjects were 13 boys who stutter (mean age = 4:0) and their mothers and 13 nonstuttering boys (mean age = 4:0) and their mothers. No significant differences were found between the two groups of children or between the two groups of mothers for any of the three paralinguistic behaviors with the exception that the mothers of nonstuttering children exhibited significantly (p < 0.01) faster rates of speech than either group of children. A strong positive correlation (r = .84) was found between stuttering children's scores on the Stuttering Severity Instrument (Riley, 1980) and the durations of the overlapping portions of their mothers' interruptions (i.e., their simultalk). Findings of this study are taken to support a facilitative demands-capacities model of conversational interaction in which mothers adjust the demands of their speaking models in response to their children's demonstrated capacities for fluent speech production.