[ Contents | Search | Next | Previous | Up ]
From: Dennis Drayna
Date: 04 Oct 2010
Time: 18:23:09 -0500
Remote Name: 156.40.70.52
I think the preceding comments raise many good points. The best data we have on this question shows that about half of individuals who come to stuttering therapy have a clear family history of stuttering. The simplest interpretation of this (although not the only interpretation) is that half of stuttering is due to inherited causes. From the point of view of geneticists, estimates made this way are often too low, because family history can be unreliable, especially for recalling things that were a problem. But for the moment, I think the estimate of one half is a good guess. What is the cause of the other half? A few factors, such as perinatal hypoxia (a failure of a newborn to begin to breathe properly at birth) and trauma to the head show very modest association with stuttering. However it's clear that these explanations are imperfect, and could only explain a very small fraction of stuttering. It can be difficult to get good measurements of things like parental behavior toward stuttering in the home, so this remains an area for more research in the future. The current interest in genetic research in stuttering comes from the fact that such research can reveal things down to the level of cells and molecules, which can provide unprecedented details about the neurological aspects of stuttering.