What does it mean when a child is late talking?
Stephen Camarata
John F. Kennedy Center on Development and Disabilities
Talking is one of the most salient developmental milestones in early
childhood. To a parent's delight, most children start talking about
the time their first birthday is celebrated. Over 90% of children
begin using words by 18 months of age. But what about the remaining
10%? Is the late onset of words simply normal developmental variation
without any long-term impact or is it an indication that something is
wrong? The answer is that late talking can be either and it is
important to determine whether this is a passing phase or a condition
requiring intervention.
What is late talking?
A parent once contacted me and was concerned that her child was not
using words at 13 months of age. She had read that first words come
in by 12 months and was rather distraught that her son hadn't met
this milestone. Like many developmental milestones, talking has a
rather variable onset, with a normal distribution of approximately
9-18 months. That is, according to a large normative study (Fenson et
al, 1992) a majority of typically developing children will begin
using first words somewhere within this age range. In terms of
age-equivalency, this is a huge span! Consider that an age deviation
(age of onset minus median divided by median) would yield a "50%
delay" for a child who in actuality has normal onset of first words
at 18 months. In the absence of a more general developmental
condition (e.g., Down Syndrome), this would simply be normal
variation.
If a child is late talking
The first thing to be said about all late talking cases is that a
medical evaluation should be completed to rule out any medical
factors contributing to the late onset of language. In addition, an
audiological examination should be performed to ensure that a major
risk factor, hearing loss, is not the cause of the late talking. If a
child is not using true words by 18 months of age, this would be
considered a form of late talking. But is this a stage of development
or a symptom of a broader clinical condition, such as autism, that
will require treatment? A number of clinical conditions include late
talking as a symptom. The fourth edition of the diagnostic and
statistical manual of the American Psychiatric Association (DSM-IV,
APA 1994) lists a number of conditions "first appearing in childhood"
that include late talking. The most prevalent include expressive
language disorder, mixed expressive-receptive language disorder,
phonological disorder, mental retardation, and some of the pervasive
developmental disorders, including autism, Rhett's syndrome and
PDD-NOS (not otherwise specified). Note that Asberger's syndrome is
characterized in the DSM-IV as normal onset of language, indicating
that late talking is not a symptom of this condition. It is also true
that many children who talk late are "nonclinical" in that they may
not begin talking until two, three, or even four years of age, yet
when talking begins they quickly catch up and have none of the
clinical conditions mentioned above. But how can a parent know what
is happening with their own child two or three year old child who
isn't talking yet? The uncertainty can be quite difficult.
Differential Diagnosis of Late Talking
Here at the Kennedy Center, many researchers are studying ways to
differentially diagnose developmental disabilities. For example,
Wendy Stone is researching methods of accurately identifying autism
in young children, a process that historically has been difficult to
identify with a high degree of certainty until a child is a bit older
(e.g., five years of age). In addition, she is working with KC
investigators Paul Yoder and Mark Wolery to study treatment for
preschoolers with autism. But the broader question is how one can
tell if a child has mental retardation, autism or other PDD, language
disorder or will simply "grow out" of the problem. Basically, the
process of differential diagnosis requires careful observation of the
child and the evaluation process should include a detailed
examination of the risk factors. In general, the fewer risk factors
evident, the more likely the late talking is a developmental
variation rather than a clinical condition. For example, several
studies over the past decade have indicated that if the only trait
evident in the child is late onset of words at age two, there is a
very high probability that the vocabulary size will be within the
normal range at the age of four (Paul, 1993, 2000; Whitehurst et al.
1992). But, Paul (1994) reported that a child with phonological
(speech sound disorders) was more likely to continue to have language
difficulty beyond age four. This suggests that a diagnostic model
should provide a systematic analysis of risk factors when
recommending treatment for late talking.
Risk Factors
If a child is not talking, what skills are also important? As
mentioned above, the quality of the child's vocalizations (e.g., are
a variety of sounds used in babbling?) is predictive of late growth.
In addition, the child's receptive language skills are important. The
children who normalized in the Whitehurst et al. report had normal
(age appropriate) comprehension and our own baseline data on late
talkers suggests that those with normal comprehension are much more
likely to normalize than those with significant comprehension
deficits. Another important domain is the nature and quality of the
child's nonverbal social interactions. Child with serious problems
such as autism are less likely to initiate nonverbal social
interactions than are children who are likely to normalize. Indeed,
reduced social interaction that can not be accounted for by the late
talking itself is a hallmark characteristic of autism or other forms
of PDD (DSM-IV). Finally, a child's nonlinguistic cognitive abilities
are an important factor. It is not surprising that late talkers often
fall below expected levels on verbally based intelligence tests.
After all, how many of us could do well on a test given in a language
we don't understand? But, late talkers who are otherwise unimpaired
should fall within the normal range on tests that examine nonverbal
cognitive abilities (e.g., the revised Leiter International
Performance Scale, Roid & Miller, 1997). If the late talker is below
expected levels on nonverbal tests (in addition to verbal tests),
this suggests a more comprehensive disability. In simple terms, these
kinds of tests predict a child's rate of learning and if cognitive
abilities are below expected levels, it is likely that the child will
learn more slowly and require more attention than peers.
Treatment for Late Talking
The language skills of any late talker, regardless of diagnosis, and
typically developing children as well, can be accelerated by applying
focused stimulation on words, word endings, sentences, and speech
sounds. Researchers at the Kennedy Center have a long and impressive
history of developing ever more effective treatments and this work
continues. If the only factor in the late talking is the late onset
of words, there is a very high likelihood that the child will
normalize within a relatively short time. All children with
disabilities can learn, so more serious problems can be improved with
appropriate treatment. It is comforting to know that the overwhelming
of people with disabilities learn to talk. An important challenge in
these more serious conditions such as autism, is making sure that the
focus of language intervention is on truly functional skills (e.g.,
useful words) and making sure that the goals are coordinated among
the special educators, preschool teachers, speech-pathologists, and
parents as these children will likely benefit from learning the same
words in each context. Unfortunately, there are many unproven (and
often expensive) treatments being offered to families that do not
directly improve talking. At this time, unlike the research to
support directly teaching a child to talk, there is not scientific
evidence to support the use of special diets, massage, muscle
exercises, nonlanguage auditory training, or chelation to treat late
talking. Moreover as Paul (2000) notes, late talking may simply be a
developmental stage or it may be a symptom of a more severe
condition. Many late talkers will normalize without treatment and
many others will normalize with an appropriate treatment program, but
regardless of whether the late talking is a stage or a symptom, all
can learn. It is important to have an accurate diagnosis, and if
needed, appropriate treatment.
Also another article on Talking and babies
http://www.babycenter.com/0_developmental-milestone-talking_6573.bc?showAll=true
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