ArticlePDF Available

Retraining left-handers and the aetiology of stuttering: The rise and fall of an intriguing theory

Authors:

Abstract

Many twentieth-century British and American educators, psychologists, and psychiatrists advocated forcing left-handed children to write with their right hands. These experts asserted that a child's decision to rely on his or her left hand was a reflection of a defiant personality that could best be corrected by forcible switching. The methods used to retrain left-handers were often tortuous, including restraining a resistant child's left hand. In contrast, those who saw left-handedness as inherited, but natural, not only disapproved of forced switching, but also often warned of its putative negative consequences, especially stuttering. These claims were given credence in the 1930s by influential University of Iowa researchers, including psychiatrist S. T. Orton, psychologist L. E. Travis, and their students. From the late 1920s until the 1950s, the Iowa researchers published articles and books connecting the etiology of stuttering to forcing natural left-handers to write and perform other tasks with their right hand. Based on their clinical studies these practitioners concluded that stutterers displayed weak laterality. The Iowa group also published detailed case studies of patients whose stuttering was putatively cured by the restoration of their left-handedness. By the late-1940s, the connection between stuttering and retraining evaporated, due in large part to the growing dominance of psychoanalytic psychiatry. Despite robust statistical and clinical evidence, the connection between forced hand switching and stuttering has largely been forgotten. Recent imaging studies of stutterers, however, have suggested that stuttering is tied to disturbed signal transmission between the hemispheres. Similar to the Iowa researchers of the 1930s, current investigators have found connections between stuttering and weak laterality.
This article was downloaded by: [Emory University]
On: 19 November 2012, At: 06:50
Publisher: Psychology Press
Informa Ltd Registered in England and Wales Registered Number: 1072954
Registered office: Mortimer House, 37-41 Mortimer Street, London W1T 3JH,
UK
Laterality: Asymmetries of Body,
Brain and Cognition
Publication details, including instructions for authors
and subscription information:
http://www.tandfonline.com/loi/plat20
Retraining left-handers and the
aetiology of stuttering: The rise
and fall of an intriguing theory
Howard I. Kushner a
a Program in Neuroscience and Behavioral Biology
& Rollins School of Public Health, Emory University,
Atlanta, GA, USA
Version of record first published: 19 Dec 2011.
To cite this article: Howard I. Kushner (2012): Retraining left-handers and the aetiology
of stuttering: The rise and fall of an intriguing theory, Laterality: Asymmetries of Body,
Brain and Cognition, 17:6, 673-693
To link to this article: http://dx.doi.org/10.1080/1357650X.2011.615127
PLEASE SCROLL DOWN FOR ARTICLE
Full terms and conditions of use: http://www.tandfonline.com/page/terms-
and-conditions
This article may be used for research, teaching, and private study purposes.
Any substantial or systematic reproduction, redistribution, reselling, loan, sub-
licensing, systematic supply, or distribution in any form to anyone is expressly
forbidden.
The publisher does not give any warranty express or implied or make any
representation that the contents will be complete or accurate or up to
date. The accuracy of any instructions, formulae, and drug doses should be
independently verified with primary sources. The publisher shall not be liable
for any loss, actions, claims, proceedings, demand, or costs or damages
whatsoever or howsoever caused arising directly or indirectly in connection
with or arising out of the use of this material.
Downloaded by [Emory University] at 06:50 19 November 2012
Retraining left-handers and the aetiology of stuttering:
The rise and fall of an intriguing theory
Howard I. Kushner
Program in Neuroscience and Behavioral Biology & Rollins School of
Public Health, Emory University, Atlanta, GA, USA
Many twentieth-century British and American educators, psychologists, and
psychiatrists advocated forcing left-handed children to write with their right hands.
These experts asserted that a child’s decision to rely on his or her left hand was a
reflection of a defiant personality that could best be corrected by forcible switching.
The methods used to retrain left-handers were often tortuous, including restraining
a resistant child’s left hand. In contrast, those who saw left-handedness as inherited,
but natural, not only disapproved of forced switching, but also often warned of its
putative negative consequences, especially stuttering. These claims were given
credence in the 1930s by influential University of Iowa researchers, including
psychiatrist S. T. Orton, psychologist L. E. Travis, and their students. From the late
1920s until the 1950s, the Iowa researchers published articles and books connecting
the etiology of stuttering to forcing natural left-handers to write and perform other
tasks with their right hand. Based on their clinical studies these practitioners
concluded that stutterers displayed weak laterality. The Iowa group also published
detailed case studies of patients whose stuttering was putatively cured by the
restoration of their left-handedness. By the late-1940s, the connection between
stuttering and retraining evaporated, due in large part to the growing dominance of
psychoanalytic psychiatry. Despite robust statistical and clinical evidence, the
connection between forced hand switching and stuttering has largely been
forgotten. Recent imaging studies of stutterers, however, have suggested that
stuttering is tied to disturbed signal transmission between the hemispheres. Similar
to the Iowa researchers of the 1930s, current investigators have found connections
between stuttering and weak laterality.
Keywords: Stuttering; Retraining; Left hand; Laterality.
Address correspondence to: Howard I. Kushner PhD, Nat C. Robertson Distinguished
Professor, Program in Neuroscience & Behavioral Biology & Department of Behavioral Sciences &
Health Education, Rollins School of Public Health, Emory University 1518 Clifton Road, NE,
5th floor, Atlanta, GA 30322, USA. E-mail: hkushne@emory.edu.
I thank the two anonymous readers of this article and Carol Kushner for their comments,
suggestions, and editorial advice. This essay expands and elaborates my brief overview essay on this
topic that appeared in The Lancet (Kushner, 2011b).
LATERALITY, 2012, 17 (6), 673693
#2012 Psychology Press, an imprint of the Taylor & Francis Group, an Informa business
http://www.psypress.com/laterality http://dx.doi.org/10.1080/1357650X.2011.615127
Downloaded by [Emory University] at 06:50 19 November 2012
Twentieth-century British, American, and Canadian educators and
psychologists routinely encouraged forcing left-handed children to write
and perform other tasks with their right hands. Rejecting the notion of
natural or inherited left-handedness, these experts asserted that a childs
decision to rely on his or her left hand was a reflection of a stubborn and
defiant personality that could best be corrected by forcible switching.
Not everyone agreed with this practice. Those who saw left-handedness
as inherited but natural not only disapproved of forced switching, but
also often warned of its putative negative consequences, especially
stuttering.
The methods used to ‘‘retrain’’ left-handers were often torturous,
including restraining a resistant childs left hand, often by ‘‘tying up the
left hand so that the right hand must be used’’ (Orton, 1937, p. 50; see
also Harris, 1990, pp. 197, 199200). These practices reflected ancient
prejudices about left-handedness that can be traced back a very long way
(Barsley, 1967, pp. 116; Coren, 1992, pp. 121). They gained ‘‘scientific’’
resonance in the early twentieth-century writings of the Italian criminol-
ogist Cesare Lombroso, who claimed that as ‘‘man advances in civilization
and culture, he shows an always greater right-sidedness as compared to...
women and savage races, [who] even when they are not properly left-
handed have certain gestures and movements which are a species of
left-handedness’’ (Lombroso, 1903, p. 442). Combining left-handers with
left-siders, Lombroso found ‘‘that left-handed people are more numerous
among criminals, and sensitive left-sided people among lunatics’’ (p. 441).
This led Lombroso to formulate a ‘‘simple hypothesis... that criminals are
more often left-handed than honest men, and lunatics are more sensitively
left-sided’’. This finding indicated that ‘‘in criminals and lunatics the right
lobe predominates very much more often than in normal persons’’
(p. 443). Thus, ‘‘while the healthy man thinks and feels with the left
lobe, the abnormal, thinks, wills, and feels more with the right’’ (p. 443).
Although Lombroso did not claim ‘‘that all left-handed people are
wicked’’, he was convinced ‘‘that left-handedness, united to many other
traits, may contribute to form one of the worst characters among the
human species’’ (Kushner, 2011a, p. 118).
Lombrosos influence can be recognised in the reasoning of experts who
justified the practice of retraining. For instance, in a 1924 letter to the British
Medical Journal Dr. H. Drinkwater claimed that his clinical experience with
more than 2000 children revealed that ‘‘the truly left-handed child, without
exception, showed some degree of retardation in mental development; in
some cases it amounted to actual feeble-mindedness’’. To reduce these
potential harms Drinkwater urged early identification and conversion of
674 KUSHNER
Downloaded by [Emory University] at 06:50 19 November 2012
left-handers (Drinkwater, 1924).
1
As late as 1946 the former chief
psychiatrist of the New York City Board of Education, Abram Blau,
warned that the increasing acceptance of left-handedness by parents and
teachers would result in severe developmental and learning disabilities for
these children (Blau, 1946, pp. 6771). To avoid such outcomes Blau insisted
that ‘‘children should be encouraged in their early years to adopt
dextrality... in order to become better equipped to live in our right-sided
world’’ (p. 184); retraining of left-handed children should be instituted as
soon as their left-hand preference was noticed (pp. 184185).
Based on similar assumptions the Duke of York, future King George VI
(18951952), had been forced to write with his right hand. The Duke, who
was naturally left-handed, also stuttered; his struggles to overcome this
affliction have recently received renewed public awareness in the 2010 film
The King’s Speech, and the book of the same name (Logue & Conradi, 2010).
In his 1958 biography Sir John Wheeler-Bennett wrote that the future King
‘‘did not stammer
2
when he first began to talk.’’ His stuttering began, writes
Wheeler-Bennett, ‘‘during his 7th and 8th years. It has been attributed to his
being naturally left-handed, and being compelled to write with his right
hand. This would create a condition known in psychology as a misplaced
sinisterand may well have affected the speech’’ (Wheeler-Bennett, 1958)
quoted in (Barsley, 1967, p. 169; see also Logue & Conradi, 2010, p. 51).
Whether or not the hand switching was at the root of the Kings stuttering is
impossible to know, but circumstantial evidence of cases like this one had
informed earlier interest and debates over the wisdom of ‘‘retraining’’
natural left-handers to become right-handers.
PROTESTS AGAINST SWITCHING
While the future King was struggling with his stammering, protests against
switching were gaining support from a growing number of reputable experts.
Psychologist Lauren Julius Harris reports that as early as the second decade
of the twentieth century a number of physicians began to suspect that the
practice of retraining left-handers could negatively affect speech develop-
ment (Harris, 1990, p. 213). For instance, in a 1917 overview of studies of
handedness Clark University educator Laura G. Smith reported that
although her survey of the schools for delinquent and ‘‘feeble-minded’’
1
Drinkwater believed that ‘‘ambidextrous children were above the average in mental capacity’’.
He asserted that ‘‘it certainly seems easier for a left-handed child to learn to do expert acts with the
right hand, than for a right-handed child to acquire manual dexterity with the left hand’’.
2
Stammering and stuttering are synonymous. British writers more often used the former while
North Americans more often, but not always, used the latter.
RETRAINING AND STUTTERING 675
Downloaded by [Emory University] at 06:50 19 November 2012
children revealed a high percentage of left-handers,
3
she attributed the cause
to societys intolerance of left-handers. Those subjected to retraining were
‘‘often humiliated and at times seriously injured by the coercive methods
used in breaking up this natural motion’’. Although she recognised that her
findings on delinquency and learning disabilities seemed ‘‘to agree with the
old idea of wickedness accompanying left-handedness’’, Smith found that
many left-handers were extraordinarily talented. Left-handers, she noted,
were ‘‘well-represented in all walks of life; the highest scholarship and honor
lists include left-handed people’’. Thus, even if a ‘‘natively left-handed
person... greatly appreciates a right-hand training’’ because it enables her/
him ‘‘to comply with the rigid rules of polite society’’, Smith lamented the
‘‘destruction of native left-handedness’’ because it ‘‘must sometimes result in
the loss of the world of talent concealed in that paralyzed member’’ (Smith,
1917, p. 32).
Echoing Smiths views, there were increasing protests against retraining of
left-handers by those who insisted that such practices had negative life-long
consequences. Writing to parents and teachers in 1917, physician J. J. Terrell
characterised forced retraining of left-handers as a ‘‘ruthless’’ practice that
‘‘imperils a childs mental development’’. The documented differences in
effects of strokes on speech in left- and right-handers were for Terrell further
evidence of different brain organisation and hemispheric functioning in
right- and left-handers. Given this biological reality, to avoid greater harms,
educators and parents should ‘‘let left-handedness alone’’ (Terrell, 1917,
pp. 190, 192).
Writing in the popular journal Good Health in 1922, Harvey Ernest
Jordan, Professor of Histology and Embryology at the University of
Virginia, specifically rejected Lombrosos claims that left-handers were
criminals and defectives. ‘‘Instead of being regarded as something inherently
derogatory,’’ Jordan wrote that left-handedness ‘‘deserves appreciation and
understanding’’.Itwas‘‘the treatment still generally accorded the left-
handed in our educational systems’’ that was, according to Jordan,
responsible for the ills they experienced. He especially deplored ‘‘forcing
constitutional left-handed individuals to become right-handed’’. Such
practices only were a ‘‘little short of criminal’’ because they disrupted ‘‘the
synergy between speech center and hand center’’. This disruption placed a
child at risk ‘‘of developing serious speech defects,’’ including ‘‘many cases of
stammering and stuttering’’ (Jordan, 1922, pp. 379, 382383).
3
Her survey of Trenton State School for Girls, the Hallowell State School for Girls and the
Shirley Industrial School for Boys revealed that ‘‘15% of the boys and 6.5% of the girls are left-
handed’’. Moreover, Smith found that in institutions for the feeble-minded in Maine and Rhode
Island, 11% of the girls and 8.5% of the boys were left-handed (p. 32).
676 KUSHNER
Downloaded by [Emory University] at 06:50 19 November 2012
Like Jordan, other critics of switching pointed to reports of a much higher
incidence of stuttering among retrained left-handers. ‘‘The most impressive
of these reports,’’ writes Harris, were three produced by J. P. Ballard in
19111912 (Harris, 1990, p. 213). Based on his findings Ballard concluded
that ‘‘it is clear that there is nothing to be gained by trying to make a left-
handed child right-handed’’. On the contrary, ‘‘there is a grave risk of
stammering resulting from the change’’ (Ballard, 1911/1912, p. 308).
Published in an obscure pedagogical journal, Ballards studies might have
gone unnoticed were it not for their republication in the influential 1914
textbook The Hygiene of the School Child by Stanford University psychol-
ogist Lewis M. Terman.
Terman examined all three of Ballards studies in great detail. Ballards
first study was based on a questionnaire sent to 13,189 South London
schoolteachers. Of the 3% (545) of left-handed children, 399 had been
retrained to write with the right hand (Ballard, 1911/1912, pp. 299300).
Ballard labelled these children ‘‘dextro-sinistrals’’. Only 1.1% of the left-
handed children who were not switched stuttered, as compared to 4.3% of
the forced right-handers. Based on his interpretation of Ballards data in his
first study, Terman concluded that one-third to half ‘‘of the stuttering among
London school children is produced in the effort to make right-handed
children out of those who are normally left-handed’’. Thus, wrote Terman,
forcing left-handers to become right-handed increased the risk of stuttering
by a factor of four. Ballards second study had found that, while only 1.6% of
right-handers were stutterers, 20% of the dextro-sinistrals stuttered. Terman
found Ballards third study of 11,939 school children ‘‘still more decisive’’.In
that study 322 were left-handed, of which ‘‘271 had been required to write
with the right hand. Of these, 46 stuttered at the time’’ and an additional 24
had stuttered previously but recovered. ‘‘Of the 51 sinistrals who had been
permitted to use the left hand, not one stuttered’’. This evidence, Terman
told his readers, showed that ‘‘left-handed children should remain left-
handed’’ and that ‘‘the slight advantages that accrue from the change are
entirely outweighed by the dangers to speech’’ (Terman, 1914, pp. 345346).
Although Termans views were influential, especially among those in the
new fields of child development and education, many teachers and practicing
physicians were sceptical. In an article published in the Medical Record in
1921 in Pasadena, California, educator Ernest Tompkins concluded that
there was ‘‘no connection between stammering and the use of hands’’
(Tompkins, 1921, p. 943). Similarly, writing in the British Medical Journal in
1924, Scottish physician William Elder questioned claims associating
‘‘stammering... with left-handedness’’. If this is so, wrote Elder, ‘‘is it not
more reasonable to suppose that the stammering which may have come on
during the training of a child to use the right hand is not the result of such
training, but rather the derangement often associated with left-handedness?’’
RETRAINING AND STUTTERING 677
Downloaded by [Emory University] at 06:50 19 November 2012
(Elder, 1924, pp. 8081). Nevertheless, as University of Illinois educator
Dora Keen Mohlman wrote in 1923, ‘‘the opinion that teaching the left-
handed child to use his right hand causes disturbances in the mechanism of
speech has been widely discussed and seems to have been rather widely
accepted’’ (Mohlman, 1923, p. 216).
These second-hand observations were given authoritative credence by two
influential University of Iowa researchers, psychiatrist Samuel Torrey Orton
(18791948) and psychologist Lee Edward Travis (18961987). Orton was
the founding director of the State Psychopathic Hospital in Iowa City and
chairman of the Department of Psychiatry at the University of Iowa, College
of Medicine, while Travis, founder of the new profession of speech pathology,
was director of the universitys speech clinic. From the late 1920s until the
1950s, both collaboratively and separately, Orton and Travis published a
series of articles and books connecting the aetiology of some stuttering to
forcing natural left-handers to write and perform other tasks with their right
hand, and to those who relied on both hands for these tasks, often
categorised as ambidextrous (Orton & Travis, 1929).
While Travis focused on speech pathology, Orton connected their findings
to the aetiology of reading disorders. Orton was persuaded that stuttering
was ‘‘often an expression of confusion of cerebral dominance’’ (Orton, 1927,
p. 671). In fact, Orton believed that like the causes of stuttering, cerebral
confusion was also implicated in reading disabilities, including ‘‘dyslexia’’.
4
For the vast majority of children, wrote Orton, heredity determined which
hemisphere was dominant for language, with most being left brained (thus
right-handed) for language and writing. ‘‘One side of the brain,’’ Orton
asserted, ‘‘is all important in the language process and the other side either
useless or unused’’ (Orton, 1937, p. 27). Orton reported that a number of
children who had difficulty recognising letters and confused them with their
mirror images, for example ‘‘b’’ for ‘‘d’’, either had been switched from being
left-handed or had not evidenced dominance by either hand. Orton urged
that dominance should be acquired as early as possible so as not to interfere
with the development of speech. Once dominance was evident in handed-
ness, switching the child would result in confusion manifested by speech
problems. ‘‘Many of the delays and defects in development of language
function,’’ Orton insisted, ‘‘arise from a deviation in the process of
establishing unilateral brain superiority in individual areas’’ (Orton, 1937,
p. 200). Recognising these ‘‘hereditary facts’’ will allow educators to develop
specific interventions for speech and reading disorders, especially those
aimed at strengthening the exclusive use of one hand or the other (p. 200).
4
Dyslexia was first identified in 1887 by the Ger man ophthalmologist Rudolph Berlin (Wagner,
1973). I thank an anonymous external evaluator of this manuscript for pointing out this source.
678 KUSHNER
Downloaded by [Emory University] at 06:50 19 November 2012
Although he emphasised that there were multiple causes of stuttering,
Travis, like Orton, found that approximately 50% of stutterers were left-
handers retrained to be right-handers. When seen by Travis the stutterers
often appeared to be ambidextrous, but according to Travis, ‘‘a great deal of
this ambidexterity is undoubtedly the result of attempts by parents and
teachers to convert naturally left-handed children to right-handedness’’
(Travis, 1931, p. 185). Travis noted that the same, albeit much rarer, scenario
sometimes occurred in reverse to natural right-handers. For Travis, then, the
way to cure these stutterers was ‘‘to develop in the stutterer strict one-
sidedness’’; one hemisphere should be in complete control. So-called
ambidextrous children were thus at greater risk of becoming stutterers
than strongly lateralised children. Because the onset of stuttering, according
to Travis, was usually prior to 8 years of age, interventions should begin
early. For a majority of stutterers the way to do this was by re-establishment
of their left-handed dominance: ‘‘When it is decided that a right-handed
stutterer should become left-handed, it is necessary that he make the change
as complete as possible’’ (p. 186).
In 1937 King Georges assistant private secretary, Sir Alan Lascelles,
asked the Kings speech therapist, Lionel Logue, whether ‘‘forcing left-
handed children to act as if they were right-handed could cause... speech
impediments such as stammering’’. Logue responded affirmatively, adding
that the stammering ‘‘may disappear if the patient is changed back to his
natural hand’’. However, Logue wrote that such an intervention would not
help the King because ‘‘after 10 years of age it becomes increasingly difficult
to change the patient back again, and I have rarely heard of a case in which it
has proved satisfactory in middle life’’ (Logue & Conradi, 2010, p. 132).
Apparently Logue was not familiar with the work of researchers at the
University of Iowa who had published numerous case studies, examined in
detail below, claiming that switching back to left hand use could cure or
reduce stuttering even in older patients the Kings age (Johnson & Duke,
1935).
As early as 1931 Travis published case studies of his patients illustrating
the restoration of left-handedness as a successful treatment for stuttering.
5
For instance, he reviewed in great detail the case of an 18-year-old left-
handed male who ‘‘began to stutter after being forced to do all his writing
5
A similar but more wide-ranging claim was made by Child psychiatrist Ira S. Wile (1894
1943), President of the American Orthopsychiatric Association and former New York City
Commissioner of Education. Wile examined cases of 17 children who had been switched from left
to right-handers. The group presented with an array of physical and behavioral difficulties ranging
from enuresis, stuttering and learning difficulties to disruptive behaviors such as lying and stealing.
In each case, the children were switched back to their natural hands and their negative behaviors,
stuttering, and enuresis were eliminated (Wile, 1932, pp. 4955).
RETRAINING AND STUTTERING 679
Downloaded by [Emory University] at 06:50 19 November 2012
with his right hand’’. Although the patient had a family history of left-
handers and stutterers, Travis discounted these as the aetiological basis of
stuttering in this patient. In fact Travis rejected claims that left-handedness
itself was always a disability. He noted that while ‘‘various studies have
shown that left-handedness is relatively prevalent among the physically and
mentally defectives’’,
6
‘‘just as any trait... may occur unassociated with any
other,’’ he knew ‘‘dozens of left-handed individuals not only of average but
also of very superior physical and mental organization’’ (Travis, 1931, p. 56).
Instead of heredity, Travis tied his patients stuttering to forced conversion to
right-handed writing. Underlying this claim was the fact that 6 months after
the patient was retrained to use his left hand ‘‘he was entirely free from his
stuttering’’. And Travis was pleased to report that 5 years later the former
patient was ‘‘enjoying normal speech’’ (pp. 179180).
Travis also cited reports by other practitioners whose patients ‘‘recovered
normal speech after they were permitted to go back to the use of the left
hand’’. This intervention, Travis reported, ‘‘has been applied in our clinic on
a relatively large scale’’. One member of his staff, Dr Leo Fagan, reported
that 33 putatively ‘‘right-handed’’ ‘‘stutterers were required to use the left
hand on all major activities and to condition speaking with writing.... At
the end of a two-year period nine of the twenty-six cases were completely
normal in speaking, seven were markedly improved, eight were noticeably
better, and two had long since dropped training’’ (Travis, 1931, pp. 190191;
7
see also Van de Water, 1932, pp. 163168).
In 1935 two of Traviss former graduate students, Wendell Johnson
8
and
Lucille Duke, published an elaborate series of case reports of 16 stutterers, 10
males and 6 females aged 571,
9
14 of whom were left-handers, made to
write with their right hands. ‘‘Care has been taken,’’ Johnson and Duke
wrote, ‘‘to see that each case presented is such as would in all probability be
regarded quite generally as illustrative of a relation between stuttering and
changes of handedness.’’ All 16, either due to accident or design, reverted to
writing with their originally dominant hand. Subsequently all the stutterers
were either cured or their stuttering was substantially ameliorated.
6
‘‘This fact,’’ wrote Travis, ‘‘helps to account for the feeling of apprehension on the part of
parents and teachers regarding left-handedness’’ (Travis, 1931, p. 56).
7
Travis believed that other interventions, including psychotherapy, were also useful additions
for treating stutterers: ‘‘A main goal to be achieved in the education of the stutterers attitude
toward his trouble is his impersonal evaluation of disability. He must learn to objectify it, and in
some cases accept it’’ (p. 184).
8
Johnson (19061965), a stutterer himself, went on to have a long and distinguished career as a
psychologist and speech pathologist at the University of Iowa.
9
Six of the cases were aged 5 to10, three were 12 to18, and six were 20 to 71 (20, 26, 30, 37, 39,
and 71). The six females ranged from 10 to 30 years.
680 KUSHNER
Downloaded by [Emory University] at 06:50 19 November 2012
The first case was of H.T., a 37-year-old male who from infancy had been
trained by his mother to use his right hand, despite his growing preference
for his left hand. According to his mother H.T. ‘‘had practically no speech
until four and one-half years of age’’, which his mother attributed to her
sons obstinacy. The childs right-hand training was reinforced by his
teachers when H.T. entered school at age 6. By this time H.T. talked, ‘‘but
had difficulty in pronouncing words’’. H.T. ‘‘was taught to write with the
right hand and during this year the onset of stuttering occurred’’. His
stuttering ‘‘increased in severity until it reached its most severe stage during
adolescence’’. Both H.T.s parents and teachers ‘‘considered [him] thor-
oughly right-handed’’, despite the fact that ‘‘he remained ambidextrous in
untrained activities and preferred the left hand for heavy manual activity’’.
H.T.s‘‘stuttering remained the same’’ until, at age 32, he suffered a severe
injury when his right hand was caught in farm machinery, forcing him to
temporarily and then permanently revert to using his left hand for all tasks.
H.T. ‘‘experienced extreme irritability during the period of changing, but
toward the end of the second year of using the left hand his speech showed
decided improvement’’. Over the next 3 years, according to Johnson and
Duke, H.T. ‘‘continued to use the left hand for a significant proportion of
manual activities, and he seems to enjoy normal speech. His speech during
the personal interviews showed no evidence of stuttering.’’ Johnson and
Duke ruled out suggestion as the cause of H.T.s recovery from stuttering: ‘‘It
is of special interest,’’ they wrote, ‘‘that the patient professed essential
ignorance as to the reason for the disappearance of the stuttering. When it
was suggested that perhaps the change of handedness was responsible,
he expressed astonishment and was loath to accept the explanation’’
(pp. 114115).
R.S., on the other hand, was a 10-year-old natural right-handed male
whose speech had developed normally. When R.S. was 6 he contracted
poliomyelitis and when the ‘‘crippled condition of the right hand forced him
to use the left hand entirely for a period of four or five months, [severe]
stuttering developed’’. As soon as R.S.s right hand began to improve, his
‘‘father bound the patients left hand to the body for a period of three
months to ensure the use of the right. Toward the end of that time, the
stutter began to improve.’’ The more R.S. could rely on his right hand
the more fluent his speech became. An examination at the Speech Clinic
laboratory confirmed reports by the childs teachers and parents his
stuttering had disappeared (p. 116).
And so it went through the remaining 14 patients. The onset of each
patients stuttering had followed forced retraining that led to reliance on the
non-dominant hand. With the exception of R.S., and a 71-year-old male
(case #9) who stuttered after a stroke resulted in the loss of the use of his
right hand, all were left-handers retrained to use their right hand for writing.
RETRAINING AND STUTTERING 681
Downloaded by [Emory University] at 06:50 19 November 2012
Typically the patients resembled C.G., a 10-year-old male, who had been
writing with his left hand when, at age 7, ‘‘his teacher changed him to the
right hand. Shortly after this change in handedness, he began to stutter.
He continued to use the right hand for a period of two years, during which
time he continued to stutter.’’ C.G. was brought to the Iowa Speech Clinic in
April 1931, where ‘‘it was advised that he return to the use of the left hand in
all activities. He did so, and his stuttering began to improve.’’ By November
of that year ‘‘the patients mother reported in considerable detail that the
patient was then talking normally [and] his motor speed had increased in
every way, his writing was much improved, he was more sociable, was
generally happier’’ (pp. 117118). Based on these case reports Johnson and
Duke found ‘‘a clear indication that changes in handedness are associated
with the onset or disappearance of stuttering’’ and ‘‘that in the sixteen cases
here presented there appears to be evidence of a temporal relation between
stuttering and changes in handedness’’ (Johnson & Duke, 1935, pp. 112,
131132).
10
Two years later in his widely used textbook Reading, Writing, and Speech
Problems in Children, Orton wrote that reversal of training, ‘‘that is, a free
use of the left hand for all one sided acts’’, could, in some cases be ‘‘followed
by a complete disappearance of the stuttering within a few weeks’’ (Orton,
1937, pp. 194195). But Orton also warned his readers that these successes
had given rise to the misleading belief ‘‘that all stutterers should have been
left-handed and ought to be so trained. This rests on a very superficial
comprehension of the complexities of the problem of cerebral dominance
and of the potential sources of difficulty.’’ Although, similar to his cured
patient, many stutterers demonstrated ‘‘no clear preference for either hand’’,
some, especially ‘‘those with a very strong hereditary lading [sic] toward
stuttering*are as clearly as we can determine exclusively right-sided from
the beginning’’ (p. 195).
Ortons nuanced views were endorsed and expanded by Traviss former
student Bryng Bryngelson (18921979), who became director of the speech
clinic at the University of Minnesota in 1933, a position he held until his
retirement in 1960. Bryngelson served as President of the American Speech-
Language-Hearing Association (ASHA) from 1943 to 1944. He identified
two types of stutterers. The first were those who seemed to be untroubled by
their stuttering. Bryngelson found this to be true in children and adults ‘‘who
have stuttered since the onset of speech. It is an interesting observation that
these folk show no marked abnormal reactions to anything about themselves
or to their environments in general. They meet the requirements of well
10
According to author Benson Bobrick, Johnsons own attempt to cure his stuttering by
switching to left-handedness failed, although Johnson had no evidence that he had been forced to
become a right-hander in the first place (Bobrick, 1995, p. 129).
682 KUSHNER
Downloaded by [Emory University] at 06:50 19 November 2012
adjusted personalities’’ (Bryngelson, 1935, p. 194). The second group
consisted of ‘‘those who are decidedly sensitive about the fact that they
stutter’’. These stutterers, wrote Bryngelson, inherit ‘‘a deepseated neurolo-
gical disturbance of the central nervous system’’. Bryngelson endorsed his
mentor Traviss‘‘theory of cerebral dominance’’ which views ‘‘stuttering as a
conflict between higher and lower neural levels’’. Bryngelson argued that the
stutterers brain lacks a dominant gradient of excitation in one cerebral
hemisphere of sufficient potentiality to integrate the bilateral structures of
speech. Similar to John Hughlings Jacksons theories of dissolution
(Kushner, 2011a, p. 118), Bryngelson found that for these stutterers ‘‘cortical
control is lacking, and the speech function is under the dominance of
subcortical levels’’ (Bryngelson, 1935, p. 195).
Like Orton and Travis, Bryngelson tested his theories in the clinic. He
reported that ‘‘among 127 school children who stuttered... [he] found that
81% had been shifted from left to right in handedness’’. According to
Bryngelson, stuttering could be traced to ‘‘ambidexterity in some of the
individuals... to left-handed tendencies not responding completely to right-
handed training; in other cases there may be varying degrees of inherent
handedness’’. These findings convinced Bryngelson to ‘‘favor the view that
stuttering is produced by altering the native unilateral lead, or is due to a
lack of a dominant physiologic lead in either cerebral hemisphere’’
(Bryngelson & Clark, 1933, p. 387). Further studies served to confirm these
earlier results. In a 1941 report of 78 stutterers and 78 normal controls 1731
years of age, Bryngelson found that ‘‘the high incidence of shift of
handedness and ambidexterity in the stutterer seem[s] to appear rather
consistently in other groups of stutterers studied at the University of
Minnesota Speech Clinic’’. Combined with data on 1421 other patients,
Bryngelson reported ‘‘shifting of handedness in 73 per cent of the cases, and
53 per cent were ambidextrous’’ (Bryngelson, 1940, p. 152). From these
clinical studies Bryngelson concluded that ‘‘stutterers as a rule fall into the
mixed dominance group. In other words, the central mechanism of a
stutterer appears to be in a state of ambilaterality, neither the right nor the
left cerebral hemisphere exercises a dominant lead control over the other’’
(p. 153).
11
Other researchers in the 1940s reported similar findings. Reviewing the
past two decades of research on ‘‘various branches of science to the study of
handedness and its relation to speech’’, renowned London neurologist
W. Russell Brain (18851966) reported in the Lancet in 1945 that ‘‘there is
11
Bryngelson was not dogmatic about his findings. He admitted that ‘‘there is no reason to
believe that, because the search for the aetiology of stuttering has obtained for nearly 2,000 years,
this is the age in which speech pathologists will find its ultimate and final truth’’ (p. 155).
RETRAINING AND STUTTERING 683
Downloaded by [Emory University] at 06:50 19 November 2012
considerable evidence correlating stuttering with anomalies of handedness’’
(Brain, 1945, p. 837).
Not everyone agreed with Orton, Travis, and Bryngelson. For instance,
University of North Carolina educator K. C. Garrison cited the results of a
4-year ‘‘campaign to cureleft-handedness’’ by the Elizabeth, New Jersey,
public schools, during which ‘‘left-handedness was reduced from 250 cases
to sixty-six cases’’. According to the school officials, ‘‘not a single case of
defective speech resulted’’. Garrison concluded that ‘‘reversal of handed-
ness in writing seldom results in stuttering or other speech defect(s)’’
(Garrison, 1938, p. 328). The reason ‘‘why a change of handedness in
writing is not followed by defective speech in a majority of children, and
has actually been known to be followed by stuttering in others, may be
explained,’’ wrote Garrison, ‘‘by the nervous condition of the child and the
methods used to effect a change’’ (p. 328). That is, rather than the change
itself, it was the ‘‘antagonistic methods used to effect a change in
handedness’’ that caused the ‘‘various types of disorders when nervous
instability is present. In a nervous child persistent antagonism in any
form,’’ insisted Garrison, ‘‘can be followed by serious complications’’
(p. 329). Garrison cited Bryngelson and Rutherfords 1937 study (Bryn-
gelson & Rutherford, 1937) that reported ‘‘four times as much ambidex-
terity in the stuttering group as in the control group, and approximately
eight times as much shifting of handedness is experienced by the stutterers’’
as evidence that left-handedness and stuttering had common roots in
childhood neurosis (Garrison, 1938, p. 329).
PSYCHOANALYTIC RESPONSES
By the mid-1940s the connection between stuttering and retraining seemed
to evaporate and arguments like Garrisons above increasingly dominated. In
large part this reflected the growing dominance of psychoanalytic psychiatry
in the post World War II era, which tied a number of behaviours, including
those that today we would label as developmental disorders, like stuttering,
to early childhood trauma (Kushner, 1999, pp. 99118). Although the
University of Iowa group was not opposed to psychoanalytic formulations
they remained eclectic, drawing on psychoanalytic theories as part of a wider
set of explanations for the cause of some, but never all, stuttering.
From an orthodox Freudian perspective the left-handedness of stutterers
was read as evidence of a combination of poor parenting and childhood
rebellion rather than the result of retraining or weak laterality. As early as
1931 Boston psychoanalyst Isador H. Coriat (18751943) had written that
stammering was caused by ‘‘the fear of the ego being overwhelmed by the all-
powerful auto-eroticism’’. Coriat claimed that ‘‘stammerers frequently have
literal dreams of nursing. Stammering becomes, therefore, a form of
684 KUSHNER
Downloaded by [Emory University] at 06:50 19 November 2012
gratification of the original oral libido which continues as a post-natal
gratification in talking.’’ Thus, wrote Coriat, ‘‘the confirmed stammerer
tenaciously retains his earliest source of pleasure, that is nursing; he reacts to
the original oral binding of the mouth through a compulsive-repetition
localized in the speech mechanism, that is, in the tongue, lip, and jaw
movements of the original physiological nursing activities.’’ Coriat con-
cluded, ‘‘stammering is not a speech defect, but a psychoneurosis’’ like any
other ‘‘narcissistic disorder’’. That is, stuttering required ‘‘analytic treat-
ment’’ that ‘‘should be undertaken only by those who have had a long and
varied experience with psychoanalysis... and should be carried out in what
may be termed a pure culture, without any admixture of phonetic training’’
(Coriat, 1931, pp. 154155).
By the 1940s the growing influence of European e´migre´psychoanalysts
combined with newly trained American psychoanalytic psychiatrists to
reframe the understanding of a wide variety of paediatric developmental and
learning disabilities, including autism, hyperkinesias, Tourette syndrome,
and stuttering (Kushner, 1999, pp. 99118). Like Coriat earlier, psycho-
analyst Else P. Heilpern (1941) rejected the widely held view that stuttering
resulted from ‘‘a disease on the organic neurophysiological level’’ in favour
of the psychoanalytic ‘‘insight into the stutterers previously hidden
unconscious mechanisms’’, revealing the importance of such factors as
repressed ‘‘homosexuality, masturbation, anal eroticism, identification with
the father, return to baby speech, humiliation, secretiveness, etc.’’. Moving
beyond Coriats emphasis on oral fixation, Heilpern included the role of anal
fantasies as a cause of stuttering. She endorsed and translated into English
the views of Viennese (later Berlin) psychoanalyst Otto Fenichel (18971946)
that stuttering was ‘‘a pregenital conversion neurosis presupposing an
erotization of the speech function; the disturbance which concerns the
speech function involves infantile sexual strivings; regularly it has a
pregenital, mostly anal, and underlying oral character; its aims are almost
constantly of an exhibitionistic and sadistic nature’’ (Heilpern, 1941,
pp. 9495). By 1938 Fenichel had settled in Los Angeles. His earlier views
on stuttering were imported into his authoritative 1945 English-language
psychoanalytic textbook The Psychoanalytic Theory of Neurosis (Fenichel,
1945, pp. 288290).
This psychoanalytic orthodoxy penetrated every aspect of educational
psychology. The disappearance from the literature of the connection
between stuttering and forced hand switching was one of its collateral
results. This turn towards psychoanalysis is evident in the arguments of
New York City school psychiatrist Abram Blau, discussed earlier. Blaus
widely influential 1946 text The Master Hand: A Study of the Origin and
Meaning of Left and Right Sidedness and its Relation to Personality and
Language identified three general causes of what he labelled ‘‘sinistrality’’:
RETRAINING AND STUTTERING 685
Downloaded by [Emory University] at 06:50 19 November 2012
(1) ‘‘Inherent deficiency’’, (2) ‘‘Faulty education’’, and (3) ‘‘Negativism’’.
The first group included ‘‘those with physical defects, and those with
mental ones’’, especially those who today might be labelled as having
learning disorders (Blau, 1946, p. 87). ‘‘Sinistrality,’’ insisted Blau, ‘‘is a
developmental anomaly of preferred laterality, and represents a mishap to
the normal development of dextrality’’ (p. 182). Thus sinistrality arises
from faulty education in which there is ‘‘an absence of adequate
educational opportunities or from a direct encouragement of sinistral
tendencies’’ (p. 89) frequently by left-handed parents.
Finally, there was negativism. Here Blau found that ‘‘sinistrality is... a
symptom or manifestation of an attitude of opposition or negativism along
with such other signs as disobedience, refusal to eat, temper tantrums,
rebelliousness, etc.’’ (1946, p. 91). This acquisition was grounded in
psychoanalytic concepts of the conflict between infantile drives and the
educational and oppositional role of the childs mother. Inconsistent
parenting exacerbated the childs resistance and resulted in a personality
disorder marked by pathological negativism that was manifested by refusal
to adopt right-handedness. ‘‘My theory of negative sinistrality,’’ wrote Blau,
‘‘is that it springs from a contrary emotional attitude to the learning of right-
handedness... so that left-handedness is the result’’ (pp. 112113). For Blau,
‘‘sinistrality’’ was ‘‘nothing more than an expression of infantile negativism
and falls into the same category of other well-known reactions of a similar
nature, such as contrariety in feeding and elimination, retardation in speech,
and general perverseness’’ (p. 113). Thus, along with Lombroso, Blau
claimed ‘‘that the dissident group has an increased number of left-sided
people’’ (p. 92).
Given his perspective, Blau particularly deplored the practice ‘‘of the past
few decades’’ in which experts ‘‘have strongly advised parents... that the
child should be free... to choose the side for himself, so that the instinctive
dominance would thus be allowed to emerge unadulterated by any outside
influences’’. Such a putatively progressive practice, Blau warned, was
‘‘neglectful, harmful, and has tended to counteract many of the normal
cultural influences for dextrality’’ (p. 90). Blau believed that education and
behaviour modification could avoid left-handedness and what he charac-
terised as its disabling sequelae (pp. 5, 19, 21, 93, 184).
Blaus psychoanalytic views were widely held by educators in the 1950s.
Mainly though, Blaus views reinforced the claims made earlier by Lombroso
that left-handedness was abnormal and that those who resisted retraining
were at great risk of learning disabilities. These views were expressed by
Brooklyn College educator and psychologist Gertrude Hildreth (1898
1984), who insisted that ‘‘children in our civilization should be trained
toward right-handedness in the basic manual skills because the occasional
advantages of being left-handed are far out-weighed by the disadvantages.’’
686 KUSHNER
Downloaded by [Emory University] at 06:50 19 November 2012
Hildreth pointed to ‘‘the physical arrangements of life’’ that are ‘‘set up for
the right-handed.’’ She urged parents and teachers to accept that ‘‘handed-
ness should be trained, not left to chance, since manual dexterity can affect
an individuals educational and vocational success.’’ Alternatively, claimed
Hildreth, through ‘‘suitable training it may be possible to reduce the number
of cases of speech disturbances, failures in writing and reading, vocational
motor handicaps, and cases of social embarrassment attributable to manual
inefficiency’’ (Hildreth, 1950, p. 101).
Similar arguments appeared in educational journals such as Milwaukee,
Wisconsin, educator Kenneth Martins 1952 article in the Journal of
Educational Research. Martin urged ‘‘educators, parents, psychologists, and
others who work with children’’ to have the childs‘‘sinistral urge corrected
when first learning to shake hands. Parental guidance is toward the dextral
greeting; such objects as rattles, spoons, pencils, play things, utensils, and
instruments must be placed in the right hand repeatedly until the child
develops the correct hand approach.’’ But Martin conceded that not all
children could be made into right-handers. ‘‘What can be done about the
child who persists in using his left hand?’’ he asked (Martin, 1952, p. 531).
Moving away from Blaus totalistic position, Martin proposed a more
flexible response, citing a 1943 article in Parents Magazine,‘‘Its No Fun to
be a Southpaw’’ (Stanford, 1943). ‘‘If we cannot change a certain
percentage of the populations preferred laterality,’’ wrote Martin, ‘‘we
must provide... those who are left-handed [to] operate at their greatest
possible efficiency.’’ American ‘‘democracy,’’ Martin wrote, ‘‘is committed
to providing an education for every child to the limit of his capacity’’. Thus
Martin urged that ‘‘left-handed work setups; work-benches and cupboard
arrangements, tool holders, irons, scissors, etc.’’ be provided at all
educational institutions. ‘‘Lighting systems that make it necessary for a
left-handed student to write in his own hands shadow; work benches in
manual art classes which cater only to the dextral, are equally discriminat-
ing’’ (Martin, 1952, p. 531).
By the late 1950s, while educational psychologists had generally rejected
Blaus draconian attitude towards left-handers, few seemed persuaded that
there was a direct cause and effect between retraining left-handers to be
right-handers and the onset of stuttering. In her authoritative 1957
investigation of educational implications of left-handedness in Scotland,
educational psychologist Margaret M. Clark concluded that ‘‘stuttering may
result from changed handedness, but whether it does or does not will depend
to a great extent on the procedure adopted in effecting the change’’ (Clark,
1957, p. 50). Stuttering was not so much a result of the attempted changes,
wrote Clark, but of the ‘‘emotional disturbance’’ which might arise from
‘‘the resistance by the child to the attempts to make him conform against his
will’’ (p. 51). What was critical was the age at which the change in
RETRAINING AND STUTTERING 687
Downloaded by [Emory University] at 06:50 19 November 2012
handedness was initiated. It was desirable ‘‘for the child to develop dominant
handedness as early as possible’’ because the older a child was, the more
developed its brain and the greater the possibility of stress, resulting in
stuttering. In addition, attempts to change handedness in children with a
‘‘deeper neurological inadequacy’’ exacerbated the risk of stuttering (p. 51).
Nevertheless, based on her review of the literature and a comprehensive
study of 330 Scottish elementary pupils, Clark believed that in the vast
majority of children ‘‘no essential difference was apparent between left-
handers and right-handers except for their use of a different hand’’ (Clark,
1957, p. 201). Clark emphasised that her finding was ‘‘no empty statement’’
but ‘‘on the contrary it... requires to be emphasized in view of current
attitudes toward the phenomenon of left-handedness’’. Rejecting Blaus
insistence that left-handers should be made into right-handers, Clark
believed that ‘‘it is imperative that the same attention be given to teaching
left-handers to write with the left hand as is devoted to right-handers’’. She
warned that ‘‘left-handers changed to right-handedness may suffer from
enforced use of the non-dominant hand’’ (p. 201). She urged educators and
parents to uncover these cases and return these children to their dominant
hand.
12
Brooklyn College speech pathologist Oliver Bloodstein (19202010), who
was sceptical of the connection between stuttering and forced hand
switching, nevertheless conceded that it was ‘‘difficult to read certain case
reports of children who began to stutter after a shift of handedness, or to
study accounts of certain adults who experienced fluency disturbances after
enforced use of the nonpreferred hand without being impressed by the
possibility that laterality is a factor in some cases’’ of stuttering
13
(Blood-
stein, 1959, p. 35, quoted in Van Riper, 1971, p. 357). Supporting that
possibility was a 1966 report by Philadelphia neurosurgeon R. K. Jones of
four stutterers who had developed aphasia prior to neurosurgery. ‘‘After
operation on one cerebral hemisphere,’’ Jones reported, ‘‘stammering
ceased.’’ Jones concluded that this result ‘‘supports the view previously
put forward, but unproved, by Travis that bilateral cortical representation is
a factor in stammering’’ (Jones, 1966, p. 195).
Reviewing the studies supporting and critical of the connection between
the onset of stuttering and forced switching of left-handers in his
authoritative textbook The Nature of Stuttering, Charles Van Riper wrote
that ‘‘most of the research indicates that the old belief that such a switch can
12
‘‘Few people realise just how common it still is for left-handers to be encouraged or forced to
use their right hand,’’ wrote Clark in 1967. ‘‘Some left-handers are permitted to write with the left
hand, but by no means all’’ (Clark, 1957, p. 38).
13
Bloodstein obtained his PhD in 1948 at the University of Iowa. Travis directed his
dissertation.
688 KUSHNER
Downloaded by [Emory University] at 06:50 19 November 2012
cause stuttering is far from being corroborated’’ (Van Riper, 1971, p. 356).
Still, it hadnt been disproved either. ‘‘It should be,’’ Van Riper claimed, ‘‘a
simple matter to dispose of this question by simply getting a large population
of individuals who have been shifted at various ages and then determining
the incidence in this group and comparing it with that of a control group
that has not been shifted’’ (p. 357). Yet, as Van Riper noted, such a study has
not been done ‘‘and so once again we are left with ambiguity instead of
ambilaterality’’ (p. 357).
Reviewing the literature on the connection between retraining and
stuttering in 1983, New Zealand psychologists Michael Corballis and Ivan
L. Beale concluded that ‘‘the theory advocated by Orton and Travis’’
deserves ‘‘reasonable support’’ and that ‘‘the time is ripe for a revival of the
dominance theory’’’ of stuttering. They pointed to ‘‘convincing evidence
that stutterers often show anomalies of cerebral localization’’. Corballis and
Beale were persuaded that ‘‘the anomaly was one of reversal rather than of
weak or absent lateralization’’ because the vast majority of these stutterers
had been ‘‘forced to switch to the right hand.’’ Thus Corballis and Beale
suggested that ‘‘the more cautious interpretation is simply that these
stutterers were without any strong predisposition toward consistent later-
alization, so that different manifestations of laterality were in conflict.’’
Citing the patients described by Jones (1966), discussed above, Corballis and
Beale noted that in ‘‘some stutterers... there may be bilateral control over
speech, leading to interhemispheric conflict’’ (Corballis & Beale, 1983) (pp.
229, 234235).
In contrast with Corballis and Beale, Harris believes that despite the
‘‘early and impressive statistical reports the notion that the training would
cause stuttering or otherwise disrupt the development of speech and
language’’ was weak. Still, Harris admits that we ‘‘know little more on
this question, pro or con, than was known in the 1930s’’. That is because
‘‘new studies of the relationship between handedness and speech disorders
have ignored the question of hand training and have focused on the broader
question whether speech disorders are more common in left-handers
generally’’. Thus Harris concedes that ‘‘it is not beyond the realm of
possibility that forced right hand training is one of several factors that put
certain left-handed children at risk for speech problems’’, especially among
‘‘those left-handers already having language or speech problems’’ (Harris,
1990, pp. 226227).
The main reason that hand retraining is no longer a subject for
investigation of the aetiology of stuttering is that the practice has
significantly diminished*especially in America and Britain, the arenas for
RETRAINING AND STUTTERING 689
Downloaded by [Emory University] at 06:50 19 November 2012
most dysfluency or stuttering research.
14
Although it is difficult to obtain
reliable data on the incidence and prevalence of stuttering even in Britain
and North America where the practice of retraining left-handed children to
adopt right-handed writing has almost disappeared, there is evidence to
suggest that the prevalence of stuttering has likewise declined (Dean &
Brown, 1977).
CONCLUSION
Even if hand switching accounted for a significant percentage of stuttering, it
cannot account for the aetiology of all stuttering; indeed, none of the Iowa
researchers in the 1930s made such a claim. Rather, what Orton, Travis and
their colleagues did insist on was that an understanding of the likely
mechanisms that underlay the connection between retraining and stuttering
opened the door to the wider issue of the role of weak laterality and
stuttering.
Although current stuttering experts remain sceptical about the Iowa
groups claims, a number of recent investigations using new imaging
technologies have reopened the possible connections between stuttering
and laterality. While their conclusions are tentative, they are intriguing. For
instance, in an MRI study of 32 adults, neurologist Anne Leigh Foundas and
colleagues found that an ‘‘anomalous anatomy’’ in the perisylvian speech-
language areas ‘‘increased risk for the development of stuttering (Foundas,
Bollich, Corey, Hurley, & Heilman, 2001, p. 207). Foundas and her
colleagues have continued these investigations and report that adults with
persistent developmental stuttering display atypical cerebral laterality
(Foundas et al., 2003, 2004). Other investigators have reported similar
findings. Reviewing a number of these reports the German team of Christain
Bu
¨chel and Martin Sommer concluded that stuttering is connected to
‘‘disturbed signal transmission’’ between the hemispheres (Bu
¨chel &
Sommer, 2004). The signalling disturbance, write Bu
¨chel and Sommer,
‘‘also explains why the normal temporal pattern of activation between
premotor and motor cortex is disturbed and why, as a consequence, the right
hemisphere language areas try to compensate for this deficit’’ (Bu
¨chel &
Sommer, 2004, p. 162).
14
According to Coren (1992), well into the 1970s many teachers, especially those at Catholic
parochial schools, ‘‘routinely attempt[ed] to force children to write with the right hand regardless of
their natural predisposition’’ (pp. 6566). Reporting on their investigations of 650 British
Columbia undergraduates, Porac and colleagues found that attempts to switch left-handers into
right-handers were common in Canada in the 1980s (Porac, Coren, & Searleman, 1986).
Combining the findings of two of Poracs studies, Coren reported that ‘‘approximately 55 percent
of all left-handers’’ recalled attempts by others to switch them from left-handedness. Of that group
64% reported the attempts were made before their eighth or ninth year of age (Coren, 1992, p. 68).
690 KUSHNER
Downloaded by [Emory University] at 06:50 19 November 2012
These findings mesh with similar claims by Orton, Travis, Bryngelson,
and their students in the 1930s. Thus current investigators have found that
those stutterers who ‘‘can use the right hemisphere for language can develop
into fluent speakers’’ (Bu
¨chel & Sommer, 2004, p. 163). And, like Orton and
Travis in the 1930s, twenty-first-century investigators have concluded that ‘‘it
is unlikely that stuttering is inherited in a simple fashion.’’ Rather they
emphasise ‘‘a multifactorial model for genetic transmission’’ in which ‘‘a
certain genotype’’ most likely ‘‘only represents a risk factor and that other
environmental factors are necessary to develop PDS’’ [persistent develop-
mental stuttering] (p. 163). Of course, all of these recent imaging studies are
suggestive rather than conclusive. As a team of Swiss researchers pointed
out, although recent studies ‘‘provide strong evidence that adults with PDS
have anomalous anatomy not only in perisylvian speech and language areas
but also in prefrontal and sensorimotor areas’’, the question remains
‘‘whether this atypical asymmetry... is the cause or the consequence of
stuttering’’ (Ja
¨ncke, Hanggi, & Steinmetz, 2004, p. 23).
For Orton, Travis, Bryngelson, and their students, weak lateralisation was
a cause rather than the result of stuttering. Sometimes they found that
reversing forced hand switching cured or relieved stuttering. In the West
forced training of left-handers to switch to their right hands has declined, as
has the incidence of stuttering. Is this a consequence of the disappearance of
training or is it a coincidence? The best way to answer that question would
be a carefully constructed randomised clinical investigation to determine
once and for all whether or not the intriguing hypotheses, developed and
employed in the University of Iowa clinics in the 1930s and 1940s, have any
validity. This would serve not simply an antiquarian interest because, outside
the West, most societies and cultures continue to practise forced retraining of
left-handers. As the British and American experiences recounted in these
pages suggest, such practices are not only discriminatory, but they may also
have deleterious consequences on physical and emotional development of
left-handers, who constitute 10% of the worlds population.
Manuscript received 25 April 2011
Revised manuscript received 4 July 2011
First published online 20 December 2011
REFERENCES
Ballard, P. B. (1911/1912). Sinistrality and speech. Journal of Experimental Pedagogy and Training
College Record,1, 298310.
Barsley, M. (1967). The other hand: An investigation into the sinister history of left-handedness.
New York: Hawthorne Books.
Blau, A. (1946). The master hand: A study of the origin and meaning of right and left sidedness and
its relation to personality and language. New York: American Orthopsychiatric Association.
RETRAINING AND STUTTERING 691
Downloaded by [Emory University] at 06:50 19 November 2012
Bloodstein, O. (1959). Stuttering for professional workers. Chicago: National Society for Crippled
Children and Adults.
Bobrick, B. (1995). Knotted tongues: Stuttering in history and the quest for a cure. London: Simon &
Schuster.
Brain, W. R. (1945). Speech and handedness. The Lancet,249, 837841.
Bryngelson, B. (1935). A method of stuttering. The Journal of Abnormal and Social Psychology,
30(2), 194198.
Bryngelson, B. (1940). A study of laterality of stutterers and normal speakers. The Journal of Social
Psychology,11, 151155.
Bryngelson, B., & Clark, T. B. (1933). Left-handedness and stuttering. Journal of Heredity,24,
387390.
Bryngelson, B., & Rutherford, B. (1937). A comparative study of laterality of stutterers and non-
stutterers. Journal of Speech Disorders,2,1516.
Bu
¨chel, C., & Sommer, M. (2004). What causes stuttering? PLoS Biol,2(2), E46.
Clark, M. M. (1957). Left-handedness: Laterality characteristics and their educational implications.
London: University of London Press.
Corballis, M. C., & Beale, I. L. (1983). The ambivalent mind: The neuropsychology of left & right.
Chicago: Nelson Hall.
Coren, S. (1992). The left-hander syndrome: The causes and consequences of left-handedness.New
York/Toronto: Free Press/Maxwell Macmillan Canada.
Coriat, I. H. (1931). The nature and analytical treatment of stuttering. Proceedings of the American
Speech Correction Association,1,51156.
Dean, C. R., & Brown, R. A. (1977). A more recent look at the prevalence of stuttering in the
United States. Journal of Fluency Disorders,2(2), 157166.
Drinkwater, H. (1924). The left-handed child (letter). The British Medical Journal,1(3312), 1113.
Elder, W. (1924). The left-handed child. The British Medical Journal,2(3315), 8081.
Fenichel, O. (1931). Hysterien und Zwangsneurosen. Vienna: Int. Psycho-analytischer Verlag.
Fenichel, O. (1945). The psychoanalytic theory of neurosis. New York: WW Norton & Co.
Foundas, A. L., Bollich, A. M., Corey, D. M., Hurley, M., & Heilman, K. M. (2001). Anomalous
anatomy of speech-language areas in adults with persistent developmental stuttering.
Neurology,57(2), 207215.
Foundas, A. L., Bollich, A. M., Feldman, J., Corey, D. M., Hurley, M., & Heilman, K. M. (2004).
Atypical planum temporale anatomy in stuttering: Relationship to delayed auditory feedback.
Neurology,63, 16401646.
Foundas, A. L., Corey, D. M., Angeles, V., Bollich, A. M., Crabtree-Hartman, E., &
Heilman, K. M. (2003). Atypical cerebral laterality in adults with persistent developmental
stuttering. Neurology,61, 13781385.
Garrison, K. C. (1938). Problems related to left-handedness. Peabody Journal of Education,15(6),
325332.
Harris, L. J. (1990). Cultural influences on handedness: Historical and contemporary theory and
evidence. In S. Coren (Ed.), Left-handedness: Behavioral implications and anomalies (pp. 195
258). Oxford, UK: North-Holland.
Heilpern, E. (1941). A case of stuttering. The Psychoanalytic Quarterly,10,95115.
Hildreth, G. (1950). The development and training of hand dominance: IV. Developmental
problems associated with handedness. The Pedagogical Seminary and Journal of Genetic
Psychology,76,39100.
Ja
¨ncke, L., Hanggi, J., & Steinmetz, H. (2004). Morphological brain differences between adult
stutterers and non-stutterers. BMC Neurology,4(1), 23.
Johnson, W., & Duke, L. (1935). Changes in handedness associated with onset or disappearance of
stuttering: Sixteen cases. The Journal of Experimental Education,4(2), 112132.
692 KUSHNER
Downloaded by [Emory University] at 06:50 19 November 2012
Jones, R. K. (1966). Observations on stammering after localized cerebral injury. Journal of
Neurology, Neurosurgery & Psychiatry,29(3), 192195.
Jordan, H. E. (1922). The crime against left-handedness. Good Health,57, 378383.
Kushner, H. I. (1999). A cursing brain? The histories of Tourette syndrome. Cambridge, MA:
Harvard University Press.
Kushner, H. I. (2011a). Cesare Lombroso and the pathology of left-handedness. Lancet,377(9760),
118119.
Kushner, H. I. (2011b). Retraining the Kings left hand. Lancet,377(9782), 19981999.
Logue, M., & Conradi, P. (2010). The kings speech, how one man saved the British monarchy.
New York: Sterling Publishing Co.
Lombroso, C. (1903). Left-handedness and left-sidedness. The North American Review,177(562),
440444.
Martin, K. L. (1952). Handedness: A review of the literature on the history, development and
research of laterality preference. The Journal of Educational Research,45(7), 527533.
Mohlman, D. K. (1923). A preliminary study of the problems in the training of the non-preferred
hand. Journal of Educational Psychology,14(4), 215230.
Orton, S. T. (1927). Studies in stuttering. Introduction. Archives of Neurology & Psychiatry
(Chicago),18, 671672.
Orton, S. T. (1937). Reading, writing and speech problems in children. New York: WW Norton & Co.
Orton, S. T., & Travis, L. E. (1929). Studies in stuttering: Studies of action currents in stutterers.
Archives of Neurology & Psychiatry (Chicago),21,6168.
Porac, C., Coren, S., & Searleman, A. (1986). Environmental factors in hand preference formation:
Evidence from attempts to switch the preferred hand. Behavioral Genetics,16(2), 251261.
Smith, L. G. (1917). A brief survey of right and left-handedness. The Pedagogical Seminary,24,
1925.
Stanford, M. A. (1943). Its no fun to be a southpaw. Parents Magazine,18, 24, 76.
Terman, L. M. (1914). The hygiene of the school child. Cambridge, MA: Riverside Press.
Terrell, J. J. (1917). Let left-handedness alone. Illustrated World,27, 190192.
Tompkins, E. (1921). Stammering and left-handedness. Medical Record,100(26), 941943.
Travis, L. E. (1931). Speech pathology: A dynamic neurological treatment of normal speech and
speech deviations. New York/London: D. Appleton & Co.
Van de Water, M. (1932). Why stutterers stutter. The Science News-Letter,21(570), 162168.
Van Riper, C. (1971). The nature of stuttering. Englewood Cliffs, NJ: Prentice-Hall.
Wagner, R. (1973). Rudolf Berlin: Originator of the term dyslexia. Annals of Dyslexia,23,5773.
Wheeler-Bennett, S. J. W. (1958). King George VI: His life and reign. New York: St. Martins Press.
Wile, I. S. (1932). The relation of left-handedness to behavior disorders. American Journal of
Orthopsychiatry,2,4457.
RETRAINING AND STUTTERING 693
Downloaded by [Emory University] at 06:50 19 November 2012
... Retraining left-handed children to become right-handers was a common practice in the early twentieth century (Kushner, 2012), and still endures in some societies (Kushner, 2013). One intriguing theory even proposed that stuttering could have its etiology in the retraining of left-handers (Kushner, 2012). ...
... Retraining left-handed children to become right-handers was a common practice in the early twentieth century (Kushner, 2012), and still endures in some societies (Kushner, 2013). One intriguing theory even proposed that stuttering could have its etiology in the retraining of left-handers (Kushner, 2012). This specific area of research is particularly interesting, considering that the neural adaptations following a handedness shift are of general interest to the motor neuroscience literature. ...
Article
Handedness is a dynamic and complex aspect of human behavior. Changing it through practice, either willingly or obliged by some reason, requires a considerable amount of effort. Analyzing studies that presented handedness shifts may expand our comprehension of this phenomenon, since knowing how to change it might provide insights into how it develops. Therefore, we reviewed the outcomes of handedness shifts. The results suggest that neural asymmetries related to handedness are likely a consequence of lateralized practice since they correlate with modifications in the behavioral patterns. Clearly, practice is not the only factor influencing handedness development, but it seems to play a significant role in the formation and consolidation of neural and behavioral asymmetries. Another key finding of our review is the suggestion of a ceiling effect for the capacity to change handedness direction and degree, considering none of the reviewed studies reported complete shifts in behavioral measures and brain activation patterns.
... 13 Moreover, although left-handers may be subject to higher mortality in specific events, like wars (Aggleton et al. 1994), this is largely insufficient to explain the pattern in Figure 1. 14 A positive aspect of the cohort-structure of our data is that it can attenuate the possible concern that left-handedness is misreported as a result of changing sociocultural attitudes. In the NGSS, persons of different ages were asked to declare their hand-preference in the 11 There is evidence of hand-switching practices, with left-handed pupils being forced to write with their right hand (see for instance Kushner 2012 andGuber 2019). The vertical difference between the solid and the dashed lines in Fig. 1, which measures the share of people who write with the right hand but throw with the left one, can be thought of as an approximation of the share of constrained left-handers. ...
Article
Full-text available
This paper studies the interplay between left-handedness and economic development, thereby contributing to our understanding of the relationship between evolutionary forces, human diversity and growth. We propose a novel theoretical framework in which economic development influences the prevalence of left-handedness through structural change and a genetic mechanism driven by differential fertility. In particular, the emergence of the industrial sector puts left-handers at a reproductive disadvantage, because of their lower manual ability and wages. This fertility differential changes sign as soon as the income-fertility relationship is reversed, and eventually fades away when the rise of human capital makes manual skills irrelevant. Our model thus explains the decline and subsequent recovery of left-handedness observed over the last few centuries in the Western world. We further explore the possibility that left-handedness in turn influences growth: despite their lower productivity in manual tasks, left-handers may enhance technological progress through cognitive skills that are conducive to innovation, and through their contribution to the diversity of the workforce. This implies that the link between handedness and economic performance varies across stages of development. We present empirical evidence that lends credence to the core differential-fertility mechanism of our model and suggests that left-handedness can positively contribute to growth, once the economy has reached a sufficiently high level of human capital.
... In humans, for instance, short-and long-term change of hand use has been shown to affect the emotional state. More precisely, lefthanders that were forcefully retrained to use their right hand for writing showed higher incidences of stuttering, emotional problems and fears [13][14][15]. Furthermore, studies on short-term unilateral training in right-handers show that squeezing a ball with the left hand causes a more negative perception, judgement and feeling, whereas squeezing a ball with the right hand leads to a more positive perception, judgement and feeling [16,17], reviewed in [18]. ...
Article
Spontaneous limb preferences exist in numerous species. To investigate the underlying mechanisms of these preferences, different methods, such as training, have been developed to shift preferences artificially. However, studies that systematically examine the effects of shifting preferences on behaviour and physiology are largely missing. Therefore, the aim of this study was to assess the impact of shifting paw preferences via training on spontaneous home cage behaviour, as well as anxiety-like behaviour and exploratory locomotion (Elevated plus maze test, Dark light test, Open field test, Free exploration test), learning performance (Labyrinth-maze) and stress hormones (fecal corticosterone metabolites) in laboratory mice (Mus musculus f. domestica). For this, we assessed spontaneous paw preferences of C57BL/6 J females (Nambilateral = 23, Nleft = 23, Nright = 25). Subsequently, half of the individuals from each category were trained once a week for four weeks in a food-reaching task to use either their left or right paw, respectively, resulting in six groups: AL, AR, LL, LR, RL, RR. After training, a battery of behavioural tests was performed and spontaneous preferences were assessed again. Our results indicate that most mice were successfully trained and the effect of training was present days after training. However, a significant difference of preferences between RL and LL mice during training suggests a rather low training success of RL mice. Additionally, preferences of L mice differed from those of A and R mice after training, indicating differential long-term effects of training in these groups. Furthermore, left paw training led to higher levels of self-grooming, possibly as a displacement behaviour, and more time spent in the light compartment of the Dark light test. However, overall, there was no systematic influence of training on behavioural measures and stress hormones. Different explanations for this lack of influence, such as the link between training and hemispheric functioning or the intensity and ecological relevance of the training, are discussed.
... Some previous reports indicated that LH is associated with language ability and language-related diseases, such as stuttering (Chang et al., 2008), epilepsy (Bolin, 1953), and autism (Whitehouse and Bishop, 2008). Some researchers pointed out that in the language of hemispheric dominance, the RH had a typical left hemisphere preference, while the LH had an atypical (right advantage or mixed) language advantage (Knecht et al., 2000;Szaflarski et al., 2002), when forcing to convert a left-hander into a righthander, the signal transmission was affected, which is prone to stuttering (Kushner, 2012), learning disorder, and deficit disorder with hyperactivity (Goez and Zelnik, 2008). We also found that the LH showed a decrease in rightward on the STG compared with RH, which also suggested that LH could be related to the enhancement of language lateralization in the right superior temporal gyrus. ...
Article
Full-text available
The brain structural and functional basis of lateralization in handedness is largely unclear. This study aimed to explore this issue by using voxel-mirrored homotopic connectivity (VMHC) measured by resting-state functional MRI (R-fMRI) and gray matter asymmetry index (AI) by high-resolution anatomical images. A total of 50 healthy subjects were included, among them were 13 left-handers, 24 right-handers, and 13 mixed-handers. Structural and R-fMRI data of all subjects were collected. There were significant differences in VMHC among the three groups in lateral temporal-occipital, orbitofrontal, and primary hand motor regions. Meanwhile, there were significant differences in AI that existed in medial prefrontal, superior frontal, and superior temporal regions. Besides, the correlation analysis showed that the closer the handedness score to the extreme of the left-handedness (LH), the stronger the interhemispheric functional connectivity, as well as more leftward gray matter. In general, left/mixed-handedness (MH) showed stronger functional homotopy in the transmodal association regions that depend on the integrity of the corpus callosum, but more variable in primary sensorimotor cortices. Furthermore, the group differences in VMHC largely align with that in AI. We located the specific regions for LH/MH from the perspective of structural specification and functional integration, suggesting the plasticity of hand movement and different patterns of emotional processing.
... This has resulted in several problems in the child, like stuttering, stammering, and dyslexia all due to a mechanism known as cerebral confusion which happens during retraining where the cerebral dominance gets shifted. 6,22 Ambidexterity is one possible outcome of retraining. Several studies have proven the association between schizotypy and schizophrenia with mixed handedness and mixed footedness. ...
Article
Full-text available
Objective Approximately 9 out of 10 individuals show right-hand dominance. The remaining 10% include left-hand dominant and mixed handed/ambidextrous individuals. Laterality, lateral postures or lateral preference is defined by various authors as the most comfortable posture that an individual prefers to assume. The current study aims at finding the distribution of these lateral postures and their correlation with handedness/dominant side. Materials and Methods The study was done in medical and nursing students in the age group 18 to 22 years. The patients were asked to fill a self-assessment questionnaire to determine handedness and footedness. The laterality traits were observed by asking the patients to do by themselves after an untailored demonstration. Statistical Analysis The relationship between study parameters was assessed using Chi-square test. Pearson’s correlation test was done to assess the strength of association between comfort ratings of the various laterality postures. Results In our study, 96.5% were right handed and 79.9% of patients were right footed. Also, 50.8% preferred right-hand clasping, 53.9% preferred left-arm folding, and 60.6% preferred right-leg folding. A statistically significant correlation was seen between foot preference and lateral postures and arm folding and hand clasping (p < 0.05). A significant association was also found between handedness and positive history of retraining. Sidedness did not follow any Mendelian pattern of inheritance. Conclusions Handedness is affected by genetic and environmental factors. Since cultural and traditional practices can affect the lateral postures and handedness, it is important to know the relationship between laterality postures and sidedness and the impact of retraining on them. These postures are measures of cerebral dominance and are clinically important.
... This phenomenon can be perceived as a sign of successful or efficient development [45]. In fact, a diminished degree of cerebral lateralization or an increased degree of ambidexterity has been associated with stuttering, deficit in academic skills, mental health difficulties, and schizophrenia [46][47][48][49]. ...
... This phenomenon can be perceived as a sign of successful or efficient development [45]. In fact, a diminished degree of cerebral lateralization or an increased degree of ambidexterity has been associated with stuttering, deficit in academic skills, mental health difficulties, and schizophrenia [46][47][48][49]. ...
Article
Full-text available
This paper highlights the ability of convolutional neural networks (CNNs) at classifying EEG data listening to different kinds of music without the requirement for handcrafted features. Deep learning architectures presented in this paper include CNN of different depths and different convolutional kernels. Support vector machine (SVM) taking in EEG features describing the frequency spectrum, signal regularity, and cross-channel correlation has been applied for performance comparison with CNN. The best performing CNN model presented in this paper achieves the tenfold cross-validation (CV) binary classification average accuracy of 98.94% (validation) and 97.46% (test), and the tenfold CV three-class classification accuracy of 97.68% (validation) and 95.71% (test). In comparison, the SVM classifier achieves tenfold CV binary classification accuracy of 80.23% (validation). The CNN model presented is able to not only differentiate EEG of subjects listening to music from that of subjects without auditory input, but it is also capable of accurately differentiating the EEG of subjects listening to different music. In the context of designing neural computing models for EEG analysis, this paper shows that decomposing two-dimensional spatiotemporal convolutional kernels into separate one-dimensional spatial and one-dimensional temporal kernels significantly reduces the number of trainable parameters (size) of the model while retaining the classification performance. This finding is useful, especially in designing CNN for memory-critical embedded systems for EEG processing. In neurological aspect, auditory stimulus is found to have altered the EEG pattern of the frontal lobe and the left cerebral hemisphere more than the other brain regions.
Experiment Findings
Full-text available
Exploited possibilities of FOSS bibliographic software such as Zotero, Jabref and Mendeley.
Article
Previous studies have argued that a person’s ability to write legibly with the non-dominant hand after a limited amount of practice suggests that manual skill can be easily transferred. The present study investigated the degree to which handedness can be altered by short-term practice on the highly complex manual activity of handwriting. Nine strongly right-handed individuals practiced writing with their left hand daily for 15 consecutive days. On three occasions, at baseline, at the end of the practice period and after a one-month retention interval, the similarity of left- and right-hand writing was inspected and handedness was tested by means of the Purdue Pegboard as well as handedness questionnaires. All participants demonstrated more legible writing with their left hand after practice, and the writing was more similar to that of their preferred, right-hand writing, although to different degrees. Pegboard performance improved with the left hand, but equally as much with the right, and there were no other changes in participants’ manual preference patterns. The findings of the present study do not indicate any degree of change in handedness, outside the impressive progress in left-hand writing. The large inter-individual variability, suggests that further research should focus on more individual analyses.
Chapter
This chapter discusses the cultural influences on handedness. Right-handers comprise the vast majority of the adult population. Judging from the depictions of hand use in the works of art and from the analysis of the design of weapons, tools, and other historical artifacts, they also would seem to have been the norm since prehistoric time. Handedness represents the end-product of a long and multifaceted biosocial process. The environmental role can be studied in a number of ways. One way is through direct observation of the development of hand use in the context of the social and cultural environment. Direct observations might reveal whether parents are encouraging this preference by their own actions. Observations also could be made at the preschool and school-age periods and in every social situation throughout the life span. Older children and adults can be asked directly whether their hand preference has been encouraged or discouraged, and with what result, and inquiries can be made of teachers and school administrators as to their policies and practices. Cross-cultural surveys of the prevalence of left-handedness offer another way to measure the environmental role. The reason is that, although all cultures are designed for the right-hander, the rules are applied more liberally, or flexibly, in some cultures than in others.
Article
Data was requested from 50 states and 5 protectorate-trusteeships on: (1) the total school enrollment and (2) the number of stutterers identified each year between 1964–1973. The data are interpreted with reference to past prevalence figures. Trends within the 1964–1973 period are discussed. The study lends support to Van Riper's predicted declining prevalence of stuttering, yet there was no significant changes in incidence over the 10 year period.