Effects of behavior inhibition on stuttering severity and adverse consequences of stuttering in 3-6-year-old children who stutter.

PURPOSE: The purpose of this study was to investigate whether 3- to-6-year-old children who stutter and exhibit a higher degree of behavioral inhibition (BI), a correlate of shyness, stutter more frequently and experience greater negative consequences of stuttering (per parent-report) than their peers who stutter but have lower BI.

METHOD: Forty-six children who stutter (CWS; 35 boys & 11 girls; mean age 4 years, 2 months) participated. Their degree of BI was assessed by measuring the latency to their 6th spontaneous comment during a conversation with an unfamiliar examiner (following Kagan, Reznick, & Gibbons's (1989) methodology). The frequency of stuttering and the negative impact of stuttering that CWS may have experienced was assessed using parent reports (i.e., Test of Childhood Stuttering (TOCS) Observational Rating Scale; Gillam, Logan, & Pearson, 2009).

RESULTS: We found that children's degree of BI was not associated with their speech fluency per parent report. However, children's degree of BI was significantly associated with greater negative consequences of stuttering. Specifically, among the four categories of TOCS Disfluency-Related Consequences, children's BI significantly predicted the occurrence of physical behaviors that accompany moments of stuttering (such as increased tension or excessive eye blinks). Other Disfluency-Related Consequences, such as avoidance behaviors, negative feelings, and negative social consequences, were not associated with children's behavioral inhibition tendencies. Additionally, children's stuttering severity (per the Stuttering Severity Instrument-4 scores) was significantly associated with increased physical behaviors that accompany moments of stuttering and greater negative social consequences of stuttering.

CONCLUSIONS: This study provides empirical evidence that behavioral inhibition to the unfamiliar may have salience for childhood stuttering as it predicted the development of physical behaviors associated with stuttering (e.g., tension or struggle) in 3- to 6-year-old CWS. Clinical implications of high BI for the assessment and treatment of childhood stuttering are discussed.