PURPOSE - To identify, integrate, and summarize evidence from empirical studies of the language abilities of children who stutter (CWS) and children who do not stutter (CWNS).
METHOD - Candidate studies were identified through electronic databases, the tables of contents of speech-language journals, and reference lists of relevant articles and literature reviews. The 22 included studies met the following criteria: studied both children who did and did not stutter between ages 2;0 (years;months) and 8;0, and reported norm-referenced language measures and/or measures from spontaneous language samples amenable to effect size calculation. Data were extracted using a coding manual and were assessed by application of general and specialized analytical software. Mean difference effect size was estimated using Hedges's g (Hedges, 1982).
RESULTS - Findings indicated that CWS scored significantly lower than CWNS on norm-referenced measures of overall language (Hedges's g = -0.48), receptive (Hedges's g = -0.52) and expressive vocabulary (Hedges's g = -0.41), and mean length of utterance (Hedges's g = -0.23).
CONCLUSIONS - Present findings were taken to suggest that children's language abilities are potentially influential variables associated with childhood stuttering.