Stuttering

===Cross cultural===
Cross-cultural studies of stuttering prevalence were very active in early and mid-20th century, particularly under the influence of the works of [[Wendell Johnson]], who claimed that the onset of stuttering was connected to the cultural expectations and the pressure put on young children by anxious parents, which has since been debunked. Later studies found that this claim was not supported by the facts, so the influence of cultural factors in stuttering research declined. It is generally accepted by contemporary scholars that stuttering is present in every culture and in every race, although the attitude towards the actual prevalence differs. Some believe stuttering occurs in all cultures and races at similar rates, about 1% of general population (and is about 5% among young children) all around the world.<ref name="Guitar5–6"/><ref name="craig2005"/> A US-based study indicated that there were no racial or ethnic differences in the incidence of stuttering in preschool children.<ref name="Proctor">{{cite journal|author= Proctor, A. |author2=Duff, M. |author3=Yairi, E. |year=2002|title=Early childhood stuttering: African Americans and European Americans|journal=ASHA Leader|volume=4|issue=15|page=102}}</ref><ref name="Yairi2005">{{cite journal|author= Yairi, E. |author2=Ambrose, N. |year=2005|title=Early childhood stuttering|journal=Pro-Ed}}</ref>

Different regions of the world are researched unevenly. The largest number of studies has been conducted in European countries and in North America, where the experts agree on the mean estimate to be about 1% of the general population.<ref>{{Cite book |last=Bloodstein |first=Oliver |title=A Handbook on Stuttering |date=1995 |publisher=Singular Pub. Group |location=San Diego}}</ref>{{Obsolete source|date=March 2024}} African populations, particularly from West Africa, might have the highest stuttering prevalence in the world—reaching in some populations 5%, 6% and even over 9%.<ref>{{cite journal|author = Nwokah, E|year=1988|title=The imbalance of stuttering behavior in bilingual speakers|journal=Journal of Fluency Disorders|volume=13|pages=357–373|doi = 10.1016/0094-730X(88)90004-6|issue = 5}}</ref> Many regions of the world are not researched sufficiently, and for some major regions there are no prevalence studies at all.<ref name="reese">{{cite journal|author= Sheree Reese, [[Joseph Jordania]]|title= Stuttering in the Chinese population in some Southeast Asian countries: A preliminary investigation on attitude and incidence|journal= "Stuttering Awareness Day"; Minnesota State University, Mankato|year= 2001|url= http://www.mnsu.edu/comdis/isad4/papers/reese2.html|url-status= live|archive-url= https://web.archive.org/web/20110606033525/http://www.mnsu.edu/comdis/isad4/papers/reese2.html|archive-date= 2011-06-06}}</ref>