For the 1 per cent of adults worldwide who stutter, the everyday task of picking up a phone, asking for directions, or ordering food in a restaurant can be incredibly difficult.
Stuttering is even more common in young children: as many as 4 per cent of children go through a phase of repeating or prolonging sounds or words, or getting “stuck” trying to talk.
Stuttering typically emerges between the ages of two and four, after children have already been speaking normally. As with many other childhood conditions, 80 per cent of stuttering goes away, typically well within two years after it first appears.
At this point, we don’t know if very young children’s recovery from stuttering is helped by therapy; therapy for stuttering in preschoolers don’t achieve a significantly higher success rate than the reported rate of spontaneous, untreated recovery.
Why makes people stutter?
Nobody knows what causes stuttering, but some hypotheses are increasingly being disproved, while others gain support.
The common misconception that stressful events or unresolved psychological problems from young childhood causes stuttering has literally no evidence base. This was a popular theory earlier in the 20th century, and was explored in the film The King’s Speech. But stuttering is not improved by psychological therapies, which indicates it doesn’t have a psychological cause.
In fact, genetics research, brain imaging and motor coordination research supports the idea that stuttering is caused by trouble integrating the brain “circuits” that control language formulation and the translation of spoken messages into smooth motor actions. It all suggests that a person is genetically predisposed to stuttering.
Dennis Drayna, a geneticist at the American National Institute of Health, has identified a number of plausible candidates for a gene – or multiple genes – or genetic mutations that appear to disproportionately affect people who stutter.
Luc De Nil and colleagues at the University of Toronto have demonstrated in a series of studies that people who stutter take more time to learn novel motor tasks, make more errors on such tasks, and have performances that suffer asked to complete two tasks at the same time.
Researchers from Purdue University have been able to show that adults and children who stutter tend to demonstrate less stable motor coordination while learning a new activity, such as tapping a rhythm. They have also shown that participants' speech motor coordination is affected by tasks requiring more sophisticated language skills.
This study also demonstrated that people who stutter display very subtle differences in how the brain processes language, even when listening to speech input, as opposed to talking. Such findings point to a very complex communication disorder which combines genetics with difficulties in integrating across many learning, motor and language systems, which may explain why it has not been easy to find a simple, single explanation for stuttering.
Therapies that can help
Stuttering is a very handicapping condition that impacts social interactions, vocational aspirations and even educational achievement. That’s why it’s important to seek out good therapy, even for very young children, if they are discomforted by their speaking difficulties.
Many two year olds who have trouble speaking fluently seem oblivious to their problem, so only their parents are concerned. Other toddlers, however, might express that they’re “stuck”, show signs of physical frustration, or start avoiding words that have caused them trouble in the past. Any of these reactions are reasons to seek help, in order to make speaking easier and less frustrating for the child.
Other common strategies, such as trying to force or push “stuck” words out, or gulping air before speaking, have sometimes been taught by well-meaning parents or friends. Stutterers are often advised to “take a deep breath and try again” when they’re seen having trouble – this is particularly common advice for children. But it’s actually counterproductive, rather than helpful.
For very young children, a program called Lidcombe, developed at the Australian Stuttering Research Centre in Sydney, has shown to be an effective way to help preschoolers who stutter. This is achieved by partnering speech-language pathologists with the child’s parents to create a home-based plan of intervention.
Dr Nan Bernstein Ratner is a professor of the Department of Hearing and Speech Sciences at the University of Maryland.
This article first appeared on The Conversation.