Causes

Researchers continue to study the underlying causes of developmental stuttering. A combination of factors may be involved. Possible causes of developmental stuttering include:

• Abnormalities in speech motor control. Some evidence indicates that abnormalities in speech motor control, such as timing, sensory and motor coordination, may be involved.
• Genetics. Stuttering tends to run in families. It appears that stuttering can result from inherited (genetic) abnormalities.

Stuttering resulting from other causes

Speech fluency can be disrupted from causes other than developmental stuttering. A stroke, traumatic brain injury, or other brain disorders can cause speech that is slow or has pauses or repeated sounds (neurogenic stuttering).

Speech fluency can also be disrupted in the context of emotional distress. Speakers who do not stutter may experience dysfluency when they are nervous or feeling pressured. These situations may also cause speakers who stutter to be less fluent.

Speech difficulties that appear after an emotional trauma (psychogenic stuttering) are uncommon and not the same as developmental stuttering.