On the Gender Factor in Stuttering

By Ehud Yairi, Ph.D.?ÿ?ÿ?ÿ?ÿ

Gender is one of the strongest predisposing factors for?ÿ
stuttering in that the disorder affects many more males than?ÿ alt text
females.?ÿ In older children and adults the male-to-female ratio is?ÿlarge, about 4 to 1 or greater (Craig, et al., 2002).?ÿ Except for the?ÿhigher incidence, until recently no major gender differences, either?ÿin speech or other characteristics associated with the disorder have?ÿbeen demonstrated.?ÿ Interestingly, however, in preschool children?ÿclose to stuttering onset, several studies have shown considerably?ÿ
smaller gender ratios, only 2:1 (Yairi & Ambrose, 2005), and 1:1.6?ÿ
(Kloth, et al. 1995; Mansson, 2000).

Although in the past it was suspected that the age-related?ÿsubstantial decrease in the proportion of females who stutter may be?ÿdue to processes of natural recovery, data obtained at the University?ÿof Illinoisƒ?? Stuttering Research Program on early childhood?ÿstuttering have provided strong evidence to this effect.

On the basis of systematic follow-ups of many children over?ÿseveral years, our direct observations established that, indeed, boys?ÿhave greater risk for developing chronic stuttering. Conversely,?ÿgirls who begin stuttering have a greater chance than boys to?ÿexperience natural recovery (without treatment).?ÿ Specifically, among?ÿ children who recovered there were 2.3 boys to each girl; in children?ÿwho became chronic stutterers there were 3.75 boys to each girl.?ÿ The?ÿclinical implications for early risk assessment are obvious.

We have long suspected that underlying the gender ratio in?ÿstuttering are genetic factors (likely affecting brain structures?ÿassociated with speech-language processes).?ÿ For example, in families?ÿof children who stutter, more fathers stutter than mothers and more?ÿbrothers stutter than sisters. Most recently, Cox et al. (2005)?ÿcarried this a step further reporting gender differences in?ÿchromosomal signals for stuttering.?ÿ An extremely interesting?ÿ
intersection of findings is seen here: (a) gender in stuttering is?ÿgenetically influenced ? (b) gender is a factor in natural recovery?ÿand chronic stuttering ? (c) natural recovery and chronic stuttering?ÿare genetically influenced (our study by Ambrose, Cox, & Yairi,1997).?ÿHence, the disparity in sub-populations is likely to provide?ÿa window to the understanding of stuttering, its cause, and?ÿamelioration.?ÿ All in all, the gender factor in stuttering is viewed?ÿ
as a priority research target.

References
?ÿ?ÿ?ÿ?ÿ Cox, N., Roe, C., Suresh, R., Cook, E., Lundstrom, C., Garsten,?ÿ
M., Ezrati, R. Ambrose, N., & Yairi, E. (2005).?ÿ Chromosomal signals?ÿ
for genes underlying stuttering.?ÿ Presented at the Oxford Disfluency?ÿ
Conference, Oxford University, Oxford, United Kingdom.
?ÿ?ÿ?ÿ?ÿ Ambrose, N., Cox, N., & Yairi, E. (1997).?ÿ The genetic basis of?ÿ
persistent and recovered stuttering, Journal of Speech, Language, and?ÿ
Hearing Research, 40, 567-580.
?ÿ?ÿ?ÿ?ÿ Craig. A, Tran, Y., Craig, M. & Peters, K. (2002).?ÿ?ÿ?ÿ
Epidemiology of stuttering in the communication across the entire?ÿ
life span. Journal of Speech, Language, and Hearing Research, 45,?ÿ
1097-1105.
?ÿ?ÿ?ÿ?ÿ Kloth, S., Janssen, P., Kraaimaat, F. & Brutten, G. (1995).?ÿ
Speech-motor and linguistic skills of young stutterers prior to?ÿ
onset. Journal of Fluency Disorders, 20, 157-170.
?ÿ?ÿ?ÿ?ÿ Mansson, H. (2000). Childhood stuttering: Incidence and?ÿ
development. Journal of Fluency Disorders, 25, 47-57.
?ÿ?ÿ?ÿ?ÿ Yairi, E., & Ambrose, N.?ÿ (2005).?ÿ Early childhood stuttering.?ÿ?ÿ
Austin, TX: Pro-Ed, Inc.


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