The Iceberg Theory
Joseph Sheehan has described stuttering as an iceberg in that the majority of the behaviour associated it lies beneath the surface. What lies above the surface are the visible symptoms of stuttering: blocked speech, repetition of syllables, disjointed speech, facial grimaces, blushing, visible tension in the face and neck, etc. However, Sheehan sees the greater problem with the effects of stuttering that other people cannot see: this includes shame, embarrassment (in addition to that embarassment which is physically visible), guilt, avoidance of situations, substitution of words and other tricks, etc. There can be some argument about what exactly these covert symptoms are, and they tend to vary from person to person, but it is quite evident that such behavioural symptoms do exist and they contribute significantly to the overall problem of stuttering.
It is because of these submerged aspects that non stutterers can find it very hard to comprehend completely the problem of stuttering, and why many stutterers often find that other people don't really understand what in fact they are going through. Many of the worst symptoms of stuttering lie beneath the surface so to speak, and will not be perceived by the non stutterer. A stutterer may avoid a situation if they believe they may stutter, they may also feel they don't express themselves fully or properly as they avoid long discussions or avoid certain words. This behaviour has a detrimental and restrictive effect on the stutterer's life which is arguably much worse that the discomfort of the disjointed enunciation of speech which lies above the surface. It is argauble that a person with a severe stutter who is comfortable with it and doesn't allow it to hold them back is in a better situation than a person with a mild stutter who allows their stutter to control and restrict their life.
As explained elsewhere on this site, stutterers are generally categorised as either covert or overt stutterers. This demarcation is not rigid and a stutterer may change between these categories over extended periods of time. Overt stutterers are stutterers who stutter openly and for whom most people who have more than a cursory interaction with them will recognise them as having a stutter. Covert stutterers are stutterers who use a bag of tricks to hide the fact that they have a stutter. This can even extend to close friends and family. They tend to avoid speaking if they feel they are going to stutter or block, if at all possible. If it is not possible they may substitute words for words they feel they are going to stutter on. There are many other tricks which the stutterer will develop personally as a means of hiding their stutter. Note that when describing overt stutterers, reference was made to cursory interactions. Many overt stutterers will also try to hide their stutters, especially if they are only going to be talking to a person briefly; however, they generally don't try or are unable to keep this up for a extended duration hence most people if they interact with them on a regular basis will know that they stutter.
People may find it incredible that there is such a thing as a covert stutterer; when I heard the term myself for the first time it didn't seem to make sense. In the context of the iceberg theory, a model I was initially sceptical about, it does ring home a definite truth. Many covert stutterers could even be seen as more fluent than so called normal speakers, probably because they concentrate on their fluency to a much greater extent.
Most normal speakers are not completely fluent. Many people will pause for extended periods during speech, repeat syllables and words and use filling sounds like mmmmm; most of these people would not classify themselves as stutterers and most other people would also not classify them as such. It raises an interesting question as to whether it is self-categorisation that defines a stutterer and not the fluency of their speech.
However, there is generally a overriding difference between such disfluency and disfluency associated with stuttering. Such disfluency is generally present when the speaker is trying to marshall their thoughts, speaking off the hoof, or trying to answer a question they may be unsure or not completely familiar with. They would rarely experience such disfluency when introducing themselves or trying to order a drink at a bar, speaking exercises that seldom or never cause difficulty to the normal speaker. While they may exhibit characteristics of shyness and apprehension in certain such scenarios, this will not have a deleterious effect on their speech. They also tend never to block, any pausing is generally related to searching for the appropriate word rather than a lack of ability to enunciate it. This is probably the main difference between normal disfluency and stuttering disfluency: the lack of blocking and seemingly random periods of disfluency.
With a covert stutterer, most of the symptoms of their stuttering will be beneath the surface of the iceberg. While they may stutter or block occasionally this will generally not be distinguished from the disfluency of general speech as described in the previous paragraph. Overt stutterers will experience symptoms both below and above the surface of the iceberg (as defined by the conceptual waterline). Sheehan's methodologies involves moving as much of the iceberg above the waterline as possible, thus recognising the problem and then dealing with the symptoms openly. Covert stutterers are encouraged to drop their tricks and stutter openly instead, and to use voluntary stuttering to normalise and become more comfortable with their stuttering. The same is true of overt stutterers who may be using tricks themselves to try to hide or control their stuttering. When everything is above the surface the stutterer will have acknowledged their stutter and the only symptoms they should suffer are those visible ones directly connected by most people to stuttering (i.e. blocking, interjecting fluency of speech, facial grimaces, etc.). They should no longer be substituting words or avoiding speaking situations because of a fear of how their stutter may be perceived. As the stutterer becomes more comfortable with their speaking the tension associated should also decrease along with the physical symptoms such as grimacing, tics, etc. With time, a general improvement in fluency in speech amy also develop, especially if the stutterer continues to work on their speech and utilises fluency improving methods such as voluntary stuttering and sliding.
In order to utilise the iceberg theory, the stutterer needs to define what lies within their own iceberg, both above and below the surface. This may change, especially for covert stutterers, as the iceberg floats upwards over the conceptual waterline. Sheehan gives some examples of what can lie beneath the iceberg. This can include fear, avoidance, guilt, shame, tricks, etc. An overt stutterer may rarely avoid (in which case the symptom is not as pronounced). Some stutterers may be very guilty about their speech and blame their disfluency on themselves and something they are doing, others may not experience such feelings as they feel their stuttering is not their fault but rather something they have been inflicted with. However, when a stutterer is defining the attributes of their iceberg, it is important that they define them honestly so they can monitor their progrees as they try to deal with the symptoms both below and above the water level.
It may be difficult to define exactly when the iceberg is completely above the water, and indeed it is unlikely to ever do so, as most people will always feel a little self conscious when they experience disfluency or face a feared situation, however much they may have improved from their previous situation. Generally, it can be assumed that the iceberg is largely above the waterline when the stutterer is no longer trying to avoid situations (asking directions, buying things in shops, ordering in restuarants, answering and making phone calls) and is no longer overtly self conscious about their speech (if they have something to say they say it rather than thinking of ways they could say it without stuttering or even worse substituting content for safer content). This could be summarised as the stutterer still stuttering, but dealing with it as a matter of fact part of their speech and not letting it have any other influence on their life. O.K., I stutter; I may block and interject disjointed enunciation of words, but that's just the way I talk (and hopefully I will improve as I continue to work on it) and its not going to stop me from speaking or saying exactly what I want to say with the words I want to use!
The Iceberg Theory is now generally acknowledged as an accurate model of stuttering. While it may be difficult to get the entire iceberg above the waterline (especially in the context of individual human being retaining an individuality they have developed over their entire life), increasing the visible portion of it does seem to have very positive effects. Many of the submerged behaviours exacerbate the symptoms above the surface (especially for overt stutterers) and may also exacerbate the symptoms and behaviours below the surface (also applicable to covert stutterers). While some of the behaviours below the surface may initially exacerbate the symptoms above the surface as they are pushed upwards (i.e. removing avoidence), others may have the opposite effect (i.e the stutterer removing the shame as they become more comfortable with their stuttering). When as much is possible is above the surface it should become easier to work on the symptoms and monitor the results, given that there will be much less invisible influence from below the surface.