Cause of stuttering

Stottertherapie en ademtraining met de Del Ferro methode

There are as many forms of stuttering as there are people who stutter, each with a unique personal style. What is a difficult word for some is simple for others. Nevertheless, there are many similarities in the behaviors and emotions that stuttering causes. The core is the physical cause. By addressing these, stuttering can be overcome.

Primary stuttering

People start stuttering at different times and for different reasons, with no single specific cause. Although stuttering is often thought to be hereditary, evidence does not support this, especially when in identical twins, one child stutters and the other does not.

Stuttering usually starts between the second and sixth years of life, a period when about 4% of children become less fluent. This is understandable, given that speaking is complex and requires practice. At this stage, vocabulary grows rapidly, while knowledge of sentence structure and fluency are still developing.

This temporary stumbling speech, known as primary stuttering, is separate from true stuttering and usually disappears on its own. However, in one in three children this evolves into actual stuttering, with fluency changing from relaxed to tense hiccups.

Secondary stuttering

After stumbling over words due to enthusiasm or haste, true secondary stuttering can occur. This can be seen when children linger on the same letters, avoid certain words or situations, speak in whispers or point to things instead of naming them. Their discomfort is evident when they get stuck. Physical reactions may follow, such as uncontrolled facial or limb movements, turning red, sticking out the tongue, tapping with a foot or hand, and in extreme cases, hitting oneself to get words out.

Secondary stuttering can be triggered by intense emotional events, both positive and negative. Sometimes there is no obvious cause. Once secondary stuttering develops, it leads to an anxious expectation pattern that exacerbates or perpetuates stuttering.

Although some children grow over their stuttering later in life, it is important to take action early. Without intervention, stuttering can be permanent.

Sometimes stuttering begins later in life, often due to emotional trauma or insecurity during adolescence. After puberty, it is rare for a person to begin stuttering.

Boys stutter about three times more often than girls. The reason for this is unknown. Possibly it has to do with girls’ faster development in physical, language and motor skills. Boys often receive a more achievement-oriented upbringing, which can put extra pressure on fluency. In girls, certain conditions, such as hyperventilation and eating disorders, are more common.

Psychological causes of stuttering

Whoever reveals the psychological cause of stuttering would thereby also have found the key to the solution of many human problems. This statement highlights that determining a specific psychological cause of stuttering is complex. The diversity of therapies developed reflects the varying opinions on exactly what that psychological cause means.

The Del Ferro method is not based on conventional theories about psychological causes of stuttering. This method focuses on the daily reality of people who stutter, with the idea that physical functioning contributes significantly to emotional well-being and self-confidence. The uniqueness of the Del Ferro method lies in its physical approach, with specific training of the diaphragm, also known as the diaphragm, which separates the chest and abdominal cavities.

The Del Ferro method has been thoroughly scientifically researched at several universities and in hospitals. Researchers studied X-rays of the diaphragm of both people who stutter and those with fluent speech. These studies showed that the diaphragm of people who stutter exhibits irregular movements during speech. Moreover, someone who stutters tries to speak while breathing in at the same time, which is impossible even for people who do not stutter!


At Del Ferro, we consider stuttering to be a physical condition with a psychological basis. Fundamentally, we do not focus on the cause of stuttering, as it is different for everyone. The focus is on solving the stuttering problem, not starting it.

The Del Ferro method offers tens of thousands of stuttering people in the Netherlands a real prospect of a definitive solution to their problem. This also applies to their numerous peers worldwide, rather than conducting endless psychoanalyses to determine the psychological cause of stuttering.

A great experience for our students. You never get used to it. Do you also want to live stutter-free?

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