Does Bilingualism Increase Stuttering?

Maybe, but I don’t think so. What we do know is that we don’t really know enough about how bilingualism interacts with stuttering. We know that bilingualism doesn’t make autism worse; we know that bilingualism doesn’t increase the risk of language impairment, so consistent with these findings; I think that bilingualism shouldn’t make stuttering worse. There is one study that reports that children who start learning their second language later in childhood bilinguals are less likely to stutter than bilinguals who start using both their languages from an early age. As pointed out however, it seems that the prevalence of stuttering in bilinguals is no higher (or maybe less) than that of monolinguals. I think however we need to get a handle on what stuttering looks like in bilinguals to make accurate diagnosis. We know for example that bilinguals demonstrate more tip of the tongue phenomena and that mazes (pauses, hesitations, reformulations) are different in different languages.

We recently completed a review of the literature examining published peer-reviewed articles that focused on bilingual or multilingual persons who stutter. We were curious about how researchers describe the bilingual or multilingual status of participants in their studies. What we found is that most studies included information about proficiency and we found a lot of inconsistency. About half the studies included information about bilingual history; and a little less than half included information about how people used their two (or more) languages. But, wouldn’t this be important for studies of bilinguals who stutter? It’s important to know when and how and why someone became bilingual. It would be important to know how much they use each of their languages and for what purpose(s). It would also help to know which of their two languages is better—or if they are equally proficient in both languages. These are some of the questions that could help us to understand how bilingualism and stuttering interact and would help researchers compare results across studies. So, it was surprising to find out that there are still many inconsistencies. I’m confident however that as people continue to study stuttering in bilinguals that more of these descriptions will be included.

In terms of clinical application, I think we need to be cautious and make sure that we’re not over-diagnosing or under-diagnosing stuttering. Because we don’t know enough about its manifestation in bilinguals we also don’t know if the same monolingual rules apply. So, I would probably want to observe some to make sure. On the other hand, you don’t want to wait too long before treating if it is true stuttering. I know that several people are working on these questions and we’ll know more before long.