Monday, January 08, 2007

Why kids start stuttering when their sibling is born.

I often hear people who stutter, family members, and therapists say that s/he started stuttering when their younger sibling was born. The same happened to me. So does this mean the birth of a younger sibling causes or encouraged stuttering. Should I blame my brother?

The solution is relatively simple: it's a statistical illusion but it is true!! A significant number of people who stutter started stuttering when their sibling was born. However the reason is rather mundane. Kids start to stuttering around 2.5 to 4 years of age when they start using grammar instead of just words. AND at the same time the most likely age difference between you and your younger sibling is about 2-3 years! Babies take 9 months to produce (as you probably know?), then parents are busy feeding the infant, and don't think about you-know-what-I-mean. After 2 years, they kind of forget what trouble and pain you were as an infant, and just remember your cute smile. And then your younger sibling comes along.

To summarise, due to the accidental fact that both the onset of stuttering and the age difference is three years, there is a high probability that stuttering kids have a younger sibling when they started stuttering!

Another way of looking at this effect is to ask: So if a younger sibling causes stuttering, why did not all the million other kids that have younger siblings start stuttering???

The answer is: They don't because there is no casual relationship. (At least not to first order, I still leave the option open that the arrival of a younger sibling and the "relative" neglect of the older child might aggravate stuttering and but not start it.)


Anonymous said...

This has nothing to do with this precise article, but the link may be interesting. It's about a new device for stutterers:

Anonymous said...

Jerome, this device isn't so new so. It already has 5 years and its efficiency is still controversial (look here:

And Tom, congratulations for the text. Your argumentation is perfect. I always found very strange this history of stuttering that appears after the birth of a sibling.

Tim Weldon said...


I'm responding on behalf of my 4yr old son, Theo, who first started to stammer at about 2.5 years old. He has a sister 6yrs older but I'm wondering whether the fact he was a prem baby (by 5 weeks) could have any bearing on it. When he stammers, he gets stuck on the first syllable of the word eg. mmmmmmmmmmuuuuummy , rather than m-m-m-m-mummy.

We're trying to find a speech and language therapist for him but I just wanted to ask anyone on this blog for any advice / best practise on how to move forward.

Best Rgds, Tim

Anonymous said...


When I look to my history I began to stutter when my mother has a miscarriage.
As you said there will be no first order relation.. But the born of a sibling as well a miscarriage is an emotional event.
Do emotional events within the familiy have a relation with the starting of stuttering?

At this moment I'm reading some theory of system constellations.
See also This site is setup by a stuttertherapist and systemconstellations coach / trainer.

Tom Weidig said...

Hi Tim,

for advice you can go to the website, they have a lot information on stuttering and therapies.

Hi Henk,

I am not saying that emotional events do not have an impact, but I am saying that there must be some inherent weakness present for an emotional event to have a lasting impact on speech. Emotional events might well make the stuttering worse, and then you notice it more.