An easy way of explaining what stuttering is, is to say that it is a communication disorder in which the flow of speech is interrupted by part or whole word repetitions, by prolongations of the initial sound of a word, or by abnormal silent stoppages of sounds and syllables. Usually the person who stutters might demonstrate some unusual facial and body movements that are associated with the effort to speak.
The disorder of stuttering goes deeper than the interruptions of the speech flow and it was characterized by many researchers as a “puzzle” that despite the fact that it has been studied extensively, it continues to challenge researchers.
Based on research there are four main contributing factors to stuttering:
It is estimated that 1% of the total world population stutters.
Stuttering affects four times as many males as females.
Approximately 5 percent of all children go through a period of stuttering that lasts six months or more. Three-quarters of those will recover by late childhood, leaving about 1% with a long-term problem. The best prevention tool is early intervention.
(The above information was based on materials from the above web pages and other scientific books and articles)