ABSTRACT
Individuals in families with several stutterers (five or more) and individuals in families with no stutterers were the basis of a broad study designed to elucidate both genetic and nongenetic factors relevant to stuttering. In order to examine both nongenetic hypotheses regarding the etiology of stuttering as well as environmental factors possibly predisposing to stuttering, data were collected using two structured case-history interviews and four self-report inventories. We were unable to identify prenatal, developmental, or medical factors that distinguish stutterers from their nonstuttering family members. Further, we found no evidence of (a) anxiety levels differing among stutterers, their nonstuttering family members, and nonstuttering controls; (b) familial attitudes toward speech differing between nonstuttering family members and those of nonstuttering controls; or (c) ratings of parental behavior or children's traits which distinguished stutterers from nonstuttering family members.
Subject(s)
Family , Stuttering/genetics , Environment , Female , Humans , Male , Pregnancy , Pregnancy Complications , Stuttering/psychologyABSTRACT
Recovery and persistence of stuttering were examined in the first-degree relatives of a large group of adult persistent stutters. The percentage of recovered individuals reported in these families supports the hypothesis that recovered and persistent stuttering are not independent disorders. Sex and type of relative were significant variables in the distributions of recovery and persistence of stuttering. Handedness in male subjects and birth order did not distinguish between recovered and persistent stutterers. Female recovered stutterers had significantly earlier ages of stuttering onset than the other groups (male recovered stutterers and male and female persistent stutterers). Female recovered stutterers also tended to recover earlier than male recovered stutterers, and the durations of stuttering symptoms were similar in both sexes.
Subject(s)
Stuttering/genetics , Adolescent , Adult , Age Factors , Birth Order , Child , Consanguinity , Female , Functional Laterality , Humans , Male , Sex Factors , Time FactorsABSTRACT
Time of language onset and frequencies of speech and language problems were examined in stutterers and their nonstuttering siblings. These families were grouped according to six characteristics of the index stutterer: sex, recovery or persistence of stuttering, and positive or negative family history of stuttering. Stutterers and their nonstuttering same-sex siblings were found to be distributed identically in early, average, and late categories of language onset. Comparisons of six subgroups of stutterers and their respective nonstuttering siblings showed no significant differences in the number of their reported articulation problems. Stutterers who were reported to be late talkers did not differ from their nonstuttering siblings in the frequency of their articulation problems, but these two groups had significantly higher frequencies of articulation problems than did stutterers who were early or average talkers and their siblings.
Subject(s)
Articulation Disorders/etiology , Child Language , Language Development Disorders/etiology , Language Development , Language Disorders/etiology , Sibling Relations , Stuttering/genetics , Child , Female , Humans , Male , Sex Factors , Stuttering/complicationsABSTRACT
Analyses of birth rank, age separation, and the frequency of stutterers in birth ranks before and after the proband were undertaken for the purpose of verifying or disproving conjectures made by other authors on possible relationships between family structures and stuttering. Results based on data drawn from over 300 sibships, showed (a) stutterers were randomly distributed among the birth ranks, (b) the age separation of the siblings was independent of stuttering status, and (c) the frequency of stutterers in birth ranks before the proband and the frequency of stutterers in birth ranks after the proband were not significantly different.