Physiological Factors

Genetics

Here we are talking about the characteristics that the person is born with - his or her genetic make up. Sometimes we read about "nature versus nurture", the crossing point between what is inherited and the environment within which we are brought up.

For example, it can sometimes be quite easy to guess where eye colour or height came from with our own parents and grandparents. It is not so easy to explain personality traits, although you do hear people saying "stubborn, just like his grandad"! Character is probably a mixture of both "nature" and "nurture".

Stammering also seems to be a mixture of both nature and nurture. For some there is a definite genetic link, a blood relative who has had or still has a stammer.

Gender

Boys are more vulnerable - we don't know why, but boys are more at risk of other speech, language and literacy problems too.

Oral motor skills

This is related to the planning and co-ordination of the movements of articulation - tongue, jaw, voice box, etc. Some research studies have shown differences in the oral skills of some people who stammer - these may be slower or less well co-ordinated, but are so slight that they are imperceptible without scientific measuring equipment.

Brain functioning research

Brain imaging is a new and highly complicated area of research in adults who stammer. Early findings suggest that certain aspects of language may be processed in different areas of the brain in some adults who stammer. What is not yet clear is whether this is at the root of the stammering problem or a result of difficulty in talking. Since it is not ethically possible to carry out these experiments with children, the results cannot be generalised to the younger population. This type of research will be continuing and we will keep you up to date with the latest studies.