And that provides new insight into why stuttering happens: the idea that someone is listening may play a key role.

Worldwide there are about 60 million people who stutter. In the Netherlands there are about 175,000 (about 1 percent). But they do not stutter in all circumstances. “There is anecdotal evidence that stutterers don’t stutter when alone,” said study researcher Eric Jackson. “However, this phenomenon has not been scientifically confirmed, as it is difficult to create conditions in which people believe they are truly alone.” In a new study however, researchers decided to give it another try and collect evidence for the so-called ‘talk-alone effect’.

Important

According to Jackson, it is very important to find conclusive evidence for this. “A lot of people think that stuttering is at its core a speech motor disorder,” he explains in an interview with Scientias.nl from. And although stuttering manifests itself most clearly as a ‘speech problem’, the question is whether other factors – such as social-cognitive factors – may also play a role. In addition, the “talk-alone effect” has been studied without much success for almost a century. “Because researchers always found some degree of stuttering, these studies were discontinued,” Jackson said. “We have now found a way to test the effect more directly and create conditions where the participants thought they were really alone.”

Experiment

The researchers gathered 23 adult volunteers and got them to talk in different situations. For example, participants were asked to read aloud a text and give a speech to two listeners. In another part, they were left alone to complete a fairly challenging computer task. The participants were incorrectly told that no one was listening while they performed the task. They were also told that people who speak out loud to themselves are more likely to complete the computer task.

stutter

Although the participants were somewhat misled, the study does lead to proof that stutterers do not stutter if they think they are alone. Because during the computer task, the volunteers turned out to be able to pronounce fluent sentences. “We developed a new method to convince participants that they are alone—that their speech would not be heard by a listener—and found that adult stutterers do not stutter under these conditions,” Jackson said.

deception

Although the research methods were approved by the competent committee, the question arises how ethical the study actually is. “The research is ethical,” Jackson says when asked. “There is no other way to test the ‘talk-alone effect’ without deception. It is precisely this testing that is crucial for our understanding of the role of social-cognitive factors in stuttering. In addition, the participants were notified immediately after the computer assignment and were given ample opportunity to withdraw from the study and have their data/recordings destroyed. As a stutterer, and also as someone who has many friends who stutter, I am convinced that the benefits of the study far outweigh the potential drawbacks or risks (if any).”

Being heard

The study not only proves that the ‘talk-alone effect’ actually exists, it also provides new insight into why stuttering happens. Because when stutterers are alone and think that no one is listening, the stuttering disappears like snow in the sun. This means that the perception of having a listener may play a key role. “The study provides evidence that socio-cognitive factors play a core role, be it a listener’s perception, fear of social judgment or something else,” Jackson concluded. When a stutterer is alone, there is no social component. And that could explain why the stuttering does not occur.

Advantages

Although the study cannot directly help people who stutter, it does provide benefits for them, according to Jackson. “First, there are many misconceptions and myths about stuttering,” he says. “And as a result, there is a lot of stigma surrounding the speech disorder. I believe expanding our knowledge of stuttering will increase public awareness and reduce stigma. Second, I think there has always been too much focus on the ‘speech’ aspects of stuttering. I think a greater understanding of the non-speech mechanisms (i.e. the social-cognitive) will provide insight into how we can help stutterers work on this, if of course they want to.”

According to Jackson, there will probably never be a cure for stuttering. “But improved ways to help people who stutter, yes,” he predicts. Research into the phenomenon continues. For example, in follow-up studies the researchers want to focus on young children and study at which stages social factors begin to influence stuttering.