At the 2008 Oxford Disfluency Conference, Anne Smith of Purdue University suggested that we know a great deal about the factors that cause stammering. She proposed a short statement to capture and communicate our knowledge.

The context was a discussion of the often negative perception of speech pathology as a profession and specifically, the perceived lack of efficacy of treatments for stuttering. Anne commented:

It seems to me that we contribute to the perception that we have little knowledge about stuttering or how to treat it when we state, "the cause of stuttering is unknown." The statement can be interpreted by the listener (and often is interpreted this way, I think) to indicate that all causes which have been discussed historically are equally probable - for example, the idea that an early, frightening experience causes stuttering.

In fact, we know a great deal about the factors that cause stuttering. We don't know precisely every detail explaining the development of stuttering, but we don't know every detail concerning the onset of Parkinson's disease. This fact doesn't stop scientists and clinicians from stating what is known about the causes of Parkinson's disease.

Anne suggested we need a short statement that could capture our knowledge about the cause of stuttering and communicate it clearly. She attempted to make such a statement at the meeting:

"Stuttering is a neurodevelopmental disorder involving many different brain systems active for speech - including language, motor, and emotional networks. Each infant is born with a genetic makeup that contributes to his or her probability of stuttering, however whether stuttering will develop depends upon experience. To learn to speak fluently, a child's brain must develop many different neural circuits, and these circuits must interact in very precise and rapid ways. Stuttering emerges in childhood as a symptom that the brain's neural circuits for speech are not being wired normally. For this reason, early intervention is critical, because by shaping the child's experience, we can affect the ongoing wiring process in the child's rapidly developing brain. The longer the stuttering symptoms persist in early childhood, the more difficult it is for us to change the brain's wiring, and stuttering becomes a chronic, usually lifelong problem."

July 2008