What causes stammering?

We know that young people and families want answers to this question.

Unfortunately, the answer is: we’re still not sure.

That said, it is believed that stammering has a multi-factorial cause, which means that there are probably several factors that play a role in the development of stammering. The way in which these factors interact with each other will likely differ from one child to another, which might help to explain why every child’s stammer is different.

Recent research points to two factors in particular, which are likely to play a role in the development of stammering in childhood:

• Neurological – advances in neuroscience have allowed researchers to discover small differences in the structure and function of the brains of people who stammer. For example, brain scans have shown differences in the way the brain: plans to speak, plans muscle movements for speaking and even how the brain hears speaking. However, whether these brain differences are a direct cause of stammering in children remains unclear.
• Genetic – stammering often runs in families, and although we are not yet sure which specific genes (or interaction of genes) are involved, stammering appears to be hereditary.

Are there predisposing factors that can affect your chances of developing a stammer?

As already mentioned, stammering is a complex speech disorder that is thought to involve a combination of factors. Here we list the factors that may predispose or increase the likelihood of a child stammering: 

• Genes: Research has shown that having a family member with a stammer makes it more likely that a child will develop a stammer. 
• Child’s sex: It is thought that boys are more likely to stammer than girls, although it may also be that a stammer sounds different in girls and impacts on girls differently.
• Language skills: Where a child has difficulties finding the words they need and organising these words when they speak, it can make it more difficult to speak smoothly.

It is important to note that no one factor will cause a child to start stammering.