For the most part.
We know that’s not the most clear answer, however stuttering is quite a complicated condition that experts still don’t know everything about – as a result, answers to seemingly simple questions can be quite lengthy.
When people discuss genetics, they often are asking if there is one single gene that dictates whether a person stutters, is deaf, has blue eyes etc and if these genes are passed down among relatives. However, genetics is far more complicated than that, and often there are numerous – if not hundreds – of genes that dictate even the smallest of attributes. And of course, not all personal attributes are related to genetics.
However, when it comes to stuttering, what we know is that in most? – but not all – instances, stuttering is genetic, in that it was passed down through family members.
In what situations does this happen?
Anna Hearne, our Massey University -based Speech Language Therapist says “children who stutter often have a family history of stuttering however the relationship between genetics and stuttering is far from clear. About 70% of those who stutter have a family history of stuttering, so a family history isn’t necessary for stuttering to develop. There are even cases of identical twins, who share the same genetic material, where one twin stutters and the other doesn’t.”
If you are person who stutters, then there is approximately a 70% chance that there is a person in your family who also stutters. However your stutter may not necessarily look (or sound) identical to theirs. Simply because they are more likely to stutter with certain words, letters, or sounds, or their stutter involves prolonged sounds or repetitions, does not mean that your stutter will also resemble this.
Another factor that makes the genetics of stuttering complicated, is that it seems to differ amongst men and women. The fact that stuttering is more likely to happen to males is something well-documented, and which we’ve discussed before, however, this ratio is far different if it is an inherited stutter. If there is a relative who stutters, then the case of inherited stuttering becomes 1 female to every 1.5 males, as opposed to 1 female to every 7 or 8 males.
This only serves to complicate the matter, and there is still plenty of research to be done around this.
Regardless, there is one thing we would like to make clear, which is that the fact that stuttering runs in families is due to genetics and not because stuttering is contagious or children are learning to stutter by copying a family member. Sometimes parents of children who stutter ask whether it’s possible that their child is subconsciously copying another person who stutters, but this is absolutely not true.
If you or someone in your family is a person who stutters, we welcome you to get in touch with us to find out how we can support you.
Stuttering among children is far more common than among adults with approx 10% of children developing a stutter at some stage in the preschool years. However, for unknown reasons, likely linked to the still developing brain, many pre-school children naturally stop stuttering and don’t require therapy.
Adults who stutter are likely to have been living with their stuttering since childhood. Adults who stutter are likely to have had treatment in the past (which may or may not have been helpful). However often at significant transition points such as finishing study and applying for jobs it can be helpful to review techniques and receive support from a Speech Language Therapist.