Stuttering appears to be a neurophysiological problem and not a psychological problem as it was once believed, but what causes the neurophysiological problem is still a mystery. While no single cause of stuttering has been found, some have suggested that Genetics, Neurological Components, language development may play an important role. I hope I made sense!
Stuttering is caused ... "When the Brain's Neuronal Activity, is faster than its Motor Activity" ... Thus, a matter of faulty Coordination.
Meaning .. When Ideas are faster, than the Vocal Capacity ... i.e., the Physical failing to keep up, with the Mental, Activity ...
A Dysfunctional, unsynchronised Activity, of the Brain, Larynx and Tongue, is Stuttering.
The cure is to "Cool down the Faster of the Two" ... re-learn to think and Speak in a Coordinated manner ... To Think, as fast as your larynx and tongue ... can move ... or Talk as fast as your brain can Think.