If you want to know
about stuttering causes...
...I have
tried my best to simplify all the explanations on this page.
Hopefully, if you are like me, this will help you get all the answers
and completely understand it. If not, I have provided the references to
help you search in the right direction.
PRE-DISPOSING
FACTORS
(
This is not what
causes stuttering, they are just conditions that can make a person
at-risk for it)
Heredity
- Stuttering runs in
families
- Girls are less
likely to stutter than boys
- Genetic factors are stronger in women
who don’t
recover (because most do).
Thus, their relatives are more
likely to
stutter 80%-90% of siblings stutter if their identical twin stutters
Problem with
Cerebral Localization
- People who stutter could have a delay in the
development of the left side of their brain which could affect speech
and language
- This delay happens during fetal development
- They may use the right side of their brain for
speech and language instead of the left side like usual
- Using the right brain for speech and language
is not as efficient as using the left
Problem with
Timing
- People who stutter could have a deficit
in temporal programming (or timing of their speech movements)
- Their speech and language centers are not in
the usual place so it takes longer for them to program their speech
movements
- Other brain functions can interfere with the
timing of speech movements; for example, increased emotion, controlled
by the right side of the brain, such as when a child is upset or
excited, can make the child stutter because it got in the way of the
timing
Problem with
Language Production
(Covert Repair Hypothesis, Postma
and Kolk)
- People who stutter may have an impaired
phonological encoding mechanism (basically they could have something
wrong with the place in their brain where speech is planned and
programmed)
- Activating or saying sounds is a little delayed
for people who stutter
- People who stutter try to speak faster or start
speaking too quickly
- They don’t wait long enough for their
“slow-to-activate” speech planner (delayed phonological encoding
mechanism) to choose and plan the right sounds before talking
- If phonological encoding error is detected, the
speaker may attempt to covertly repair the error before it is
articulated which results in disfluency (stutter)
- If an error in the speech plan is detected, the
brain unconsciously goes through different sounds/words until the
correct sound/word is found, this causes the disfluency or stutter
Problem with
Language Complexity
- Recently, it is found that stuttering could happen because
of the complex interface between speech motor control and language
planning (Kleinow & Smith, 2000)
- Motor control of speech is worse when the
language or message is more complex
- Children stutter more when they are saying
bigger/harder words, using more difficult grammar, and when the
sentence is longer (Bernstein Ratner & Sih, 1987, Yarruss, 1997)
No matter what pre-disposing factors look at…
…it is important to know that
there is
a lot of
evidence to show that
people who stutter DO have a physical difference in their brain.
BUT remember...
...just like other areas of speech and language, the brain is
altered by experience because of its ability to change (plasticity).
People who stutter have been able to see changes in their “different”
brain activity, after going through successful
stuttering therapy.
Bottom line,
just because there is a physical brain difference, it does not mean it
cannot be cured and it is not necessarily part of stuttering causes.
This is definitely an awesome finding for people who stutter and for
speech therapists who offer stuttering therapy.
“TRIGGERING” FACTORS
(conditions that can trigger stuttering causes)
Parents
DO NOT
cause stuttering. There are several developmental and environmental
influences for stuttering causes, but research has found that
there is no difference
between parents of children who stutter and parents of children who do
not stutter.
I repeat,
parents ARE NOT
considered to be stuttering causes.
Is that enough repeating and bolding to let you feel some relief? You
are not to blame!
Let’s face it there are a lot of things going on in a little person’s
body and head as they are growing during the pre-school years. These
can all trigger stuttering if the child is predisposed or has a
weakness for stuttering.
The developmental factors below all
influence
stuttering:
- physical development (speech motor skills, fine
motor skills)
- cognitive development (learning new skills,
mental disabilities)
- social development (social-emotional stress)
- speech-language development (grammar,
vocabulary, sentence length)
Environmental factors like stressful speaking models, stressful
speaking situations, and traumatic life events
can also influence or be
considered as stuttering causes.
However, children are often already showing some signs of stuttering
before the life event when it becomes more noticeable.
Most often if parents need to change something,
it is not that they
are speaking too fast,
it
is that they don’t allow their child who stutters enough
time to respond during a conversation.
Now that you know the factors that influence stuttering, here are the
4 theories of what
causes stuttering,
using those factors.
THEORIES
ABOUT STUTTERING CAUSES
Diagnosogenic
Theory
(Johnson)
- Stuttering happens
when a child becomes overly
sensitive to typical disfluencies (which every child has)
because of someone’s reactions.
As a result, he tries hard to avoid being disfluent
or “messing up” again
- Stuttering is in the listener’s ear, not the
child’s mouth
Communicative
Failure and Anticipatory Struggle Theory
(Bloodstein)
- Stuttering happens because of early experiences
that made the child think that speech is hard
- If the child has a hard time talking, he may
become tense, and break up his speech. Then the core stuttering
behaviors soon become a part of the speech pattern that the child
learns to dread
- Stuttering is learned, internal and external
influences both play a part
- Reactions of listeners and the environment
created at home and/or school, trigger the child to stutter
Capacities
and Demands Theory (my personal favorite)
(Starkweather)
- Children who stutter are not able to handle the
NORMAL speech, language, and situational demands so fluency is lost and
the child stutters
- Motor Skills, Language Skills, Emotional
Maturity, and Cognitive Development are all needed to talk smoothly
(capacity)
Examples
of Motor Demand:
- Child has to compete with others for a turn
to talk
- Child feels he has to talk fast so you will
listen to everything he has
to say
Example of Language Demand:
Child has a
high vocabulary or is trying to use big words while he talks
Example of Emotional Demand:
Trying to
talk while excited or upset, like talking while at a birthday party or
after getting hurt
Example of a Cognitive Demand:
Child is
talking with a lot of anxiety that he is going to stutter and be
ashamed shame if he does
Two-Factor
Learning Theory
(Brutten & Shoemaker):
- Operates on Classical Conditioning
(remember Pavlov’s dogs? it’s okay if you don’t)
- The speaker learns
to associate
speaking with a negative emotional response
- Somehow an easy, normal disfluency
becomes paired with an event that makes the child become tense. From
then on, a disfluency is tense (a stutter) even without the event
- Stuttering is an automatic reaction to
a learned stimulus
- Tense stuttering becomes associated
with everything that was a part of it
Examples:
- location during a stutter
- sounds that occurred during a stutter like
coughing, phone ringing
- people or
gender of persons listening to the stutter
- talking
on phone during a stutter
- words or
sounds said during a stutter, like words that begin with “B”
- These things can all accidentally
happen during a stutter, which then gives them the power to make a
person stutter tensely when they happen again.
Example:
The phone rang
while I was
trying to talk to my friend this morning and I stuttered. The next time
the phone rings while I am talking, I will stutter.
- Then when the person who stutters does
something on purpose to get out or “escape” from the stutter, such as
jerking their head or blinking their eye, and the stutter stops… that
behavior is now conditioned to stop a stutter in the person’s head.
(Operant Conditioning)
So
the best way to
understand stuttering causes is to take all the
theories and views of stuttering and combine them together into one
perspective. How about this one by Healey, 2000.
Stuttering causes can be considered
complex interactions of five factors (
CALMS)
- Cognitive:
thoughts, perceptions,
awareness, understanding
- Affective:
feelings, emotions,
attitudes
- Linguistic:
language skills, language
formation demands
- Motor:
control of speech movements
- Social:
affects of type of listener
and speech situation
Genetic and physical factors are necessary, but they may not be
sufficient to cause stuttering. The CALMS factors are needed as well.
The factors are unique for each child who stutters and can be a guide
to help you test, treat, and identify these stuttering causes.