It may surprise you to learn that there is no universally agreed definition of stammering, and some therapists and researchers prefer objective definitions that identify stammering based on the frequency with which a person produces certain types of dysfluency, whereas others prefer subjective definitions which identify stammering based on people’s internal experiences of difficulty getting their words out.

Most of the time, it doesn’t really matter which definition you adopt, as most people who stammer produce symptoms that are unambiguously the symptoms of stammering. However, sometimes different definitions will lead to different diagnoses—Such as in stammerers who have learned to hide their dysfluent symptoms through various forms of avoidance and word-substitution, and in people who don’t actually have any difficulty getting their words out but are highly dysfluent for other reasons. Thus, when I worked as a researcher and advertised for adults who stammer to come and take part in my experiments, although the majority of people who responded undoubtedly did stammer, there were always a few whose dysfluencies were due to other causes—such as word-finding difficulties or sentence-formulation difficulties. And although they spoke quite dysfluently, they didn’t actually stammer… or at least, they didn’t stammer according to the definition of stammering that I had adopted for my research.

Our working definition of stammering

The definition of stammering that I have also adopted for this online course is the one cited in the American Psychological Society’s Diagnostic Statistical Manual 3rd Edition (better known as the DSM3 definition)

It was first formulated in 1977 and is as follows…

“Stuttering (stammering) is a disorder in the rhythm of speech in which the individual knows precisely what he wishes to say but at the time is unable to say because of an involuntary repetition, prolongation, or cessation of a sound”.

I adopted this as my working definition because it corresponds with the experience that I personally recognise as being central to my own stammering – the experience of knowing exactly what I want to say, and yet finding myself unable to say it at the moment when I try. The words are there, ready and waiting inside my head, but when I try to say them out loud, they don’t come out.

This definition is particularly suitable for older children and adults and is well-adapted to the needs of this online course. It is particularly good at identifying and including people whose stammering is “covert” and it successfully differentiates stammerers from people whose dysfluencies stem solely from word-finding or language-formulation difficulties. It has, however, not been universally accepted, and some clinicians and researchers – especially those who work with young children who stammer – reject it, because it refers to the subjective experiences which cannot be verified in an objectively reliable way.