Purpose: Research has shown that children who stutter (CWS) demonstrate poor adaptive functioning, or poor functional, social, and psychological skills, when compared to children who do not stutter (CWNS). Previous work has also shown that preschool CWS demonstrate significantly lower effortful control than CWNS. High effortful control, or the ability to inhibit a dominant response, is predictive of high adaptive functioning in children who are exposed to a range of adversities. The purposes of this study were fourfold: (a) to investigate if the differences between preschool CWS and CWNS in effortful control extended to school-aged children; (b) to determine if effortful control could uniquely explain adaptive functioning after controlling for a diagnosis of stuttering; (c) to investigate whether effortful control was more influential to CWS than to CWNS; and (d) to investigate whether effortful control uniquely explained adaptive functioning in CWS after controlling for stuttering frequency.
Methods: Effortful control and seven core areas of adaptive functioning were investigated in 46 school-age CWS and 46 CWNS. Eight independent two tailed t-tests were used to assess whether CWS demonstrated lower effortful control than CWNS and lower adaptive functioning than CWNS in seven adaptive functioning areas: communication competence, peer competence, internalizing behaviors, externalizing behaviors, general anxiety, social anxiety, and depression. Correlation and hierarchical regression analyses were used to examine the extent to which each component of adaptive functioning was related to effortful control when controlling for age, intelligence, parent-child relationship, and stuttering group membership. Hierarchical regression analyses were used to assess the extent to which each separate component of adaptive functioning was related to effortful control in CWS only.
Results: CWS demonstrated significantly lower effortful control when measured by the Early Adolescent Temperament Questionnaire (a parent report measure of hot effortful control) than CWNS. CWS also performed more poorly in all aspects of adaptive functioning; however statistical significance was only reached for internalizing behaviors and general anxiety. The hierarchical linear regressions indicated that effortful control predicted the majority of the variance in five areas of adaptive functioning: peer competence, externalizing behaviors, internalizing behaviors, general anxiety, and depression. In the group of CWS, stuttering frequency predicted internalizing behaviors, general anxiety, and social anxiety. However, stuttering was the most important contributor to only one of the seven components of adaptive functioning, social anxiety.
Conclusions: This study with school-aged CWS extends previous work indicating that preschool CWS exhibit lower effortful control than their normally fluent peers. The fact that emotional aspects of effortful control were a stronger predictor of social functioning, internalizing behaviors, and externalizing behaviors than either a stuttering diagnosis or the quantity of stuttering, may explain the adaptive functioning deficits often observed in CWS. Because effortful control is both a powerful contributor to adaptive functioning, and is reduced in CWS, clinical therapy approaches, which boost effortful control skills, have the potential to greatly lessen the impact of stuttering for CWS.