| | Behavioral phenotypes and special education:
parent report of educational issues for children with Down
syndrome, Prader-Willi syndrome, and Williams syndrome.
Author/s: Deborah J. Fidler
Issue: Summer, 2002 Journal of Special Education
This study examined the degree to which parents are
informed about syndrome-based behaviors in children with
three genetic mental retardation syndromes: Down syndrome
(n = 21), Prader-Willi syndrome (n = 25), and Williams
syndrome (n = 21). Parents were informed regarding blatant
behavioral features associated with their children's
syndromes (especially concerning maladaptive behaviors) but
were less informed about certain subtle syndrome-based
cognitive processing outcomes. Compared to the parents of
children with the other two syndromes, parents of children
with Down syndrome were more informed about
syndrome-related behaviors; in addition, greater numbers of
individuals (e.g., parents, school psychologists, teachers,
speech-language pathologists) brought information about
children with Down syndrome into the classroom setting.
Across all three groups, the supportive educational
services received by the children were generally not
adjusted to syndrome profiles.
Over the past decade, a quiet transformation has taken
place in behavioral research on persons with mental
retardation. In earlier years, researchers compared persons
with mild, moderate, severe, and profound levels of mental
retardation. Recently, however, increasing numbers of
studies have divided research groups by participants'
etiology or cause of mental retardation. Comparing the
1980s to the 1990s, the numbers of behavioral studies
increased from 10 to 81 for Williams syndrome, from 24 to
86 for Prader-Willi syndrome, and from 60 to 149 for
Fragile X syndrome. Even for Down syndrome, the sole
disorder with a long-standing tradition of behavioral
research, the number of behavioral studies almost doubled,
rising from 607 articles during the 1980s to 1,140 articles
during the 1990s (Dykens & Hodapp, 2001).
Alongside this increase in quantity has come increased
knowledge about behavior in many of these disorders.
Indeed, there now exists an entire field of researchers
devoted to examining whether different genetic mental
retardation syndromes show specific "behavioral phenotypes"
(Dykens, Hodapp, & Finucane, 2000; O'Brien & Yule, 1995).
Although the term has been variously defined, most
researchers now agree that a behavioral phenotype involves
"the heightened probability or likelihood that people with
a given syndrome will exhibit certain behavioral and
developmental sequelae relative to those without the
syndrome" (Dykens, 1995, p. 523). This definition
highlights the increased likelihood--but not
certainty--that any individual with a specific genetic
mental retardation disorder will show particular
etiology-related behaviors.
The present study examines the degree to which parents
know about education-related behaviors in the three genetic
disorders of Down syndrome, Prader-Willi syndrome, and
Williams syndrome. Before presenting this study, however,
we review recent behavioral findings concerning each
disorder. With this evidence as background, we can then
assess the degree to which parents know about their
children's etiology-related behaviors. Our goal involves
the possibility that knowledge of such behaviors might
ultimately lead to etiology-informed intervention
strategies, an issue we revisit later.
Etiology-Related Behaviors in Three Genetic
Mental Retardation Syndromes
By choosing to study parents' knowledge of their
children with Down syndrome, Williams syndrome, and
Prader-Willi syndrome, we follow our earlier work of
describing behaviors in each syndrome (Hodapp & Fidler,
1999). We again note, however, that while work on behavior
in genetic mental retardation disorders has accumulated at
a dizzying pace, most studies are limited to only a few
well-described disorders.
Down syndrome is the most common genetic (chromosomal)
cause of mental retardation, caused in almost all cases by
a third Chromosome 21. In addition to particular genetic
and physical features, most children with Down syndrome
display specific problems in linguistic grammar, expressive
language, and articulation. For example, most children with
Down syndrome do not progress grammatically beyond the
3-year level, and their grammatical abilities almost
invariably fall below their overall mental age levels
(Fowler, 1990). Similarly, skills in expressive language,
as opposed to those in receptive language, are much more
delayed. Indeed, by the time children's mental ages reach
24 months, significant delays (6+ months) in expressive
language abilities are evident in 83% to 100% of children
with Down syndrome (Miller, 1999). Regarding articulation,
95% of parents report that others show at least occasional
difficulties understanding the speech of their child with
Down syndrome (Kumin, 1994).
Conversely, other areas are relatively strong in most
children with Down syndrome. On average, schooll-age
children with Down syndrome show levels of visuo-spatial
short-term memory that are ! or more years advanced over
identical auditory or verbal short-term memory tasks (see
Hodapp, Evans, & Gray, 1999, for a review). Such relative
strengths arise even when subtests from different
psychometric instruments are used to measure verbal
short-term memory and when researchers use either scaled
(Pueschel, Gallagher, Zartler, & Pezzullo, 1987) or
age-equivalent scores in their analyses (e.g., Hodapp et
al., 1992). As a group, therefore, children with Down
syndrome show significant (more than mental-age level)
deficits in grammar, expressive language, and articulation,
as well as relative strengths in visual short-term memory
tasks.
A second well-studied disorder, Prader-Willi syndrome,
is caused by missing genetic material from the Chromosome
15 derived from the father (either a deletion on the
paternally derived 15 or two Chromosome 15s from the
mother). Many children with Prader-Willi syndrome show
relative weaknesses on tasks involving sequential
processing (i.e., consecutive order in problem solving). In
contrast, these children perform well on tasks requiring
simultaneous processing (i.e., integration and synthesis of
stimuli as a unified whole). In one study of teens and
young adults with Prader-Willi syndrome, average
age-equivalent scores for simultaneous processing were
almost 2 years more advanced than those for sequential
processing (7.10 years vs. 5.29 years; Dykens, Hodapp,
Walsh, & Nash, 1992).
In addition to their profile of cognitive processing,
children with Prader-Willi syndrome show extreme
hyperphagia (i.e., overeating) and obsessive-compulsive
behavior. Hyperphagia has long been considered the hallmark
of Prader-Willi syndrome (Holm et al., 1993), but it also
now appears that many of these children show other
obsessions and compulsions. Comparing individuals with
Prader-Willi syndrome to same-age nonretarded persons
diagnosed with obsessive-compulsive disorder (OCD), Dykens,
Leckman, and Cassidy (1996) found few differences between
the two groups on behaviors such as hoarding objects (e.g.,
toiletries, paper, pens); ordering and arranging objects by
color, size, or shape, or until they were "just right";
needing to say or tell things; or redoing behaviors (e.g.,
tying and untying shoes). Across 100 individuals with
Prader-Willi syndrome, 94% showed obsessions (thoughts) and
71% showed compulsions (behaviors). Joined with overeating
(98%) and temper tantrums (88%), these children showed
extremely high levels of maladaptive behavior (Dykens &
Cassidy, 1996; Dykens & Kasari, 1997).
A third well-researched disorder, Williams syndrome, is
caused by a microdeletion on Chromosome 7. Children with
this syndrome generally show a characteristic "elfin-like"
facial appearance, along with heart and other health
problems (Pober & Dykens, 1996). As many as 95% of these
children suffer from hyperacusis, or hypersensitivity to
sound (Van Borsel, Curfs, & Fryns, 1997).
Apart from these medical issues, recent attention has
strongly focused on the interesting--and possibly
unique--cognitive-linguistic profile shown by most of these
children. Children with Williams syndrome show relative
strengths in language; for many years it was thought that
these children might even perform at chronological-age
levels on a variety of linguistic tasks (Bellugi, Wang, &
Jemigan, 1994). Although age-appropriate performance in
language has now been found in only small percentages of
children with Williams syndrome (Mervis, Morris, Bertrand,
& Robinson, 1999), these children nevertheless show
relative strengths in language, as well as in verbal
processing and in some areas of music (Lenhoff, 1998).
Conversely, many children with Williams syndrome perform
especially poorly on a variety of visuo-spatial tasks. In a
recent study, Mervis et al. (1999) found that 47 of 50
children with Williams syndrome showed the pattern of
weakness in visuo-spatial tasks and a relative strength in
various measures of language (e.g., vocabulary, grammar,
short-term auditory memory; see also Udwin & Yule, 1991;
Udwin, Yule, & Martin, 1987). Although not every child with
Williams syndrome shows linguistic strengths and
visuo-spatial weaknesses, the large majority do.
Children with Williams syndrome also show a wide variety
of anxieties and fears. A recent study compared the fears
reported by children with Williams syndrome to those
reported by other children with mental retardation (Dykens,
in press). A majority of the children with mental
retardation reported only two fears--their parents getting
sick and getting a shot or injection. In contrast, more
than half of the group with Williams syndrome endorsed 41
different fears. Some involved interpersonal issues like
being teased (92%), getting punished (85%), and getting
into arguments with others (85%). Others involved physical
issues, such as getting shots or injections (90%), being in
a fire or getting burned (82%), and getting stung by a bee
(79%). Still others related to these children's hyperacusis
or clumsiness (loud noises such as sirens, 87%; falling
from high places, 79%; thunderstorms, 78%). Though not
every child with Williams syndrome shows any or all of
these fears, the vast majority do appear to be overly
fearful compared to most children with mental retardation.
Two themes emerged when we summarized this large and
growing literature. First, in every instance there seems to
be a combination of strong group differences, albeit with
some within-group variation. Second, almost all of these
studies date to the 1990s, most to the past 5 years. Given
how recent these findings are, it remains unclear just "who
knows what" about such striking etiology-related behaviors.
In two earlier studies, teacher knowledge was examined
relative to the two most common genetic forms of mental
retardation, Down syndrome and Fragile X syndrome (Wilson &
Mazzocco, 1993; York, yon Fraunhofer, Turk, & Sedgwick,
1999). Both studies found that teachers were more informed
about the outcomes associated with Down syndrome than those
associated with Fragile X syndrome. One study concluded
that the practitioners surveyed did not demonstrate a
sufficient knowledge of Fragile X syndrome to ensure that
the needs of these children would be met in a classroom
(York et al., 1999).
To date, no studies exist examining parent behavioral
knowledge about children with Down syndrome, Williams
syndrome, and Prader-Willi syndrome. Because parents are
often a prominent force in the design of children's
educational programs--attending IEP meetings, advocating
for services, and advising teachers on their children's
needs--we propose that the measure of parent knowledge of
child educational characteristics serves as an indicator of
whether etiology-related characteristics are being
considered in special education. In addition, we assess the
degree to which those phenotypic characteristics
highlighted by researchers in current research have become
salient to those who know these children best, their
parents.
This study, then, presents the first exploration of
parental knowledge about the educationally related
behaviors of children with these three genetic mental
retardation disorders. Because no body of work currently
exists, we devised our own questionnaire and chose among
those etiology-related behaviors that seemed most relevant
to the school context. Using these methods, we hope to gain
important, albeit preliminary, information as to what
parents know about their children's behavior, how services
are matched to etiology-related behavior, and who brings
etiology-related behavioral information into the classrooms
of children with Down syndrome, Williams syndrome, and
Prader-Willi syndrome.
Method
Participants
Participants were parents of three groups of 5- to
21-year-old children and adolescents: 21 with Down
syndrome, 25 with Prader-Willi syndrome, and 21 with
Williams syndrome. As shown in Table 1, children in each of
the three groups were an average of 11 to 12 years of age,
and most showed mild or moderate levels of mental
retardation. In each group, most children were attending
general education classes, either full-time or part-time,
with smaller percentages in special education classrooms.
Mothers were the main respondents, and mothers and fathers'
levels of education were generally high (most had completed
college in each group). Families of children in this study
were primarily middle class, and all children were
currently living at home.
Procedure
Parents were recruited through local and national parent
organizations for each of these three syndromes. Initial
contact was established through in-person announcements
made at parent organization events by the third author.
Those interested filled out a form stating they would like
to volunteer to participate in research. Parents who
volunteered were sent a battery of questionnaires, which
they completed and then returned to the researchers via
mail. Parents received a coupon for a $3 cup of coffee at
Starbucks along with their packet of questionnaires, but no
other compensation was offered. In a small number of cases
(fewer than 5), reminder phone calls were made to increase
the response rate. The large majority of those parents
expressing an interest in this study completed the
questionnaires.
In addition to basic demographic information about
themselves, their families, and their children, parents
also completed questionnaires regarding their children's
cognitive strengths and weaknesses, maladaptive behaviors,
and current educational placement. No returned
questionnaires were excluded from the analyses.
Measures
Demographics Questionnaire. This
questionnaire asked parents about diagnostic information
(when diagnosed and at which hospital), the child's level
of intellectual impairment (borderline, mild, moderate, or
severe mental retardation), mad information about parents'
age, education level, and ethnicity.
Educational Experiences Questionnaire.
The educational experiences questionnaire was designed
specifically for this study. Items were chosen from
well-established research findings on cognitive strengths
and weaknesses and maladaptive behavior profiles for
children with each of these disorders. For example, items
pertaining to visual and verbal learning in Down syndrome
and Williams syndrome are drawn from a rich literature on
verbal and visuospatial processing strengths and weaknesses
in these two syndromes (Hodapp et al., 1992; Jarrold,
Baddeley, & Hewes, 1999; Klein & Mervis, 1999; Pueschel et
al., 1987; Udwin & Yule, 1991; Wang & Bellugi, 1994).
Though no piloting was done with this questionnaire,
colleague reviews led to revisions improving language,
phrasing, and ease of use prior to distribution.
Current placement. The first set of
questions on the educational experiences questionnaire
related to the child's current educational placement.
Parents described whether the child was currently fully
included, partially mainstreamed, or in a special day class
without mainstreaming. They also rated their satisfaction
with the child's current placement on a 5point scale (1 =
very dissatisfied, 5 = very satisfied) and whether they had
considered changing placements.
Support services. Parents were asked
whether their children currently received any of the
following services: speech therapy, physical therapy,
occupational therapy, extra reading, extra writing, extra
math, adaptive physical education, aide in the classroom,
social skills training, psychological counseling, and
one-on-one aide. Parents were then asked whether they would
like their children to receive more of these services.
Learning profile. Parents were asked to
rate the degree to which their child fit six statements
concerning cognitive-linguistic behaviors and three
concerning behavior problems on a 5-point Likert scale (1 =
not at all, 3 = somewhat, and 5 = very much).
Cognitive-linguistic functioning items included the
following: is a visual learner (DS = strength; WS =
weakness); is verbally expressive (WS = strength; DS =
weakness); is an auditory learner (WS = strength; DS =
weakness); learns through music (WS = strength); learns
well by being given the "big picture" (PWS = strength); and
needs material broken down into small steps/parts (PWS =
weakness). Behavior problem items included the following:
is frightened by loud noises (WS); needs things to be "just
right" (is perfectionistic; PWS); overeats (PWS).
Role of genetics in educational programming.
Parents were then asked about the role that genetic
diagnosis plays in their child's educational placement or
program, and the role that genetic diagnosis should play
(for both questions, 1 = not at all; 5 = very much). They
were also asked whether the child's teacher was aware of
the diagnosis and "who brings information pertaining to
[the] child's genetic diagnosis to the educational
setting." This last question asked parents to check all
that apply from among the following eight people: parent,
child's teacher, school psychologist, pediatrician or other
medical professional, resource teacher, speech therapist,
occupational therapist, and physical therapist.
Results
Current Placement, Services, and Requested
Services
As shown in Table 1, no significant differences were
found in the educational placements of children in each of
the three groups. Across all groups, most children were
being educated in either fully or partially integrated
settings, with about 40% of each group in special class
placements. There were also no differences in satisfaction
with current educational placement, F(2, 64) = 1.92, ns.
The mean satisfaction rating for parents of children with
Down syndrome was 3.33; for Prader-Willi syndrome, the mean
was 4.00; and for Williams syndrome, the mean was 3.67.
There were no significant between-group differences in the
number of hours of each special service children received
weekly, and only one between-group difference in the
percentages of students who received each service (WS > DS,
PWS for Occupational Therapy, see Table 1).
In contrast, parents in the three groups did show some
differences in their desire for extra services for their
children. Though 90.5% of children with Down syndrome
currently receive speech therapy, greater percentages of
parents of these children expressed a desire for additional
speech therapy than parents in the other two groups, [chi
square] (2, N = 65) = 12.91, p < .002. Although 38.1% of
children with Williams syndrome currently receive a
one-on-one aide in the classroom, parents of children with
Williams syndrome significantly more often expressed a
desire for more time with a one-on-one aide in the
classroom [chi square] (2, N = 65) = 11.62, p < .02 (see
Table 2).
Degree to Which Parents Are Informed
Cognitive-Linguistic Profiles. A
one-way MANOVA, with the six cognitive-linguistic items
serving as dependent variables, showed that parents in the
three groups seem to ascribe etiology-based strengths and
weaknesses to their respective children, F(12, 112) = 4.51,
p < .0001. Follow-up one-way ANOVAs on each of the
cognitive-linguistic dimensions suggest that parents of
children with Down syndrome recognized their children's
weaknesses in expressive language (see Table 3 for a
complete list of follow-up ANOVAs).
In addition, a 3 (etiology) x 2 (visual vs. auditory
processing) repeated measures ANOVA was performed to
determine whether parents knew about the visuospatial and
verbal processing profiles of their children with Down
syndrome and Williams syndrome. A significant interaction
effect was found showing that parents of children with
different syndromes rated their children differently in
their ability to process verbal versus visual information,
F(2, 67) = 6.46, p < .003. Post hoc comparisons showed that
parents of children with Down syndrome accurately rated
their children as better visual than verbal learners
(visual M = 4.20; auditory M = 2.90). In contrast,
etiology-based differences in ratings were less
consistently found among the other two groups, and parents
of children with Williams syndrome rated their children
about equal in visual and verbal learning (visual M = 3.65;
auditory M = 3.80). However, parents of children with
Williams syndrome did give significantly higher ratings to
their children on the "auditory learner" scale than either
of the other two groups (see Table 3).
A second 3 (etiology) x 2 (sequential versus
simultaneous processing) repeated measures ANOVA found no
significant interaction effect, F(2, 67) = 1.79, ns.
Parents of children with Prader-Willi syndrome did not rate
their children as better simultaneous than sequential
processors; in fact, these parents tended to consider their
children better sequential processors (for the PWS group,
sequential M = 4.44; simultaneous M = 2.90).
Behavior Problems. MANOVA results
revealed that parents were aware of their child's
etiology-related behavior problems, F(6, 124) - 9.12, p <
.0001. Compared to parents of children with Down syndrome
and Williams syndrome, parents of children with
Prader-Willi syndrome rated their children higher on
overeating and obsessive-compulsive behavior; similarly,
parents of children with Williams syndrome gave higher
ratings to their child's being afraid of loud sounds (see
Table 3 for follow-up one-way ANOVA analyses).
The Role of Genetic Syndrome in Educational
Placement
A one-way ANOVA showed etiology-based differences in how
important parents feel their children's genetic syndromes
are to their current educational program, F(2, 63) = 3.45,
p < .05. Parents of children with Down syndrome rated their
children's syndrome as more important for educational
purposes (M = 4.09 on a 5-point scale, where 1 = very
unsatisfied and 5 = very satisfied) than parents of
children with Williams syndrome (M = 2.95) but not
Prader-Willi syndrome (M = 3.48). When asked how many
different practitioners bring syndrome-related information
to the classroom, parents of children with Down syndrome
listed significantly more people than the other two groups,
F(2, 63) = 16.23, p < .0001. The mean number of people
listed by parents of children with Down syndrome was 3.38,
whereas parents of children with Prader-Willi syndrome
listed 1.52 people and parents of children with Williams
syndrome listed 1.25 people, on average. Compared to
parents of children with Prader-Willi syndrome or Williams
syndrome, parents of children with Down syndrome noted
significantly more often that etiology-based information
was brought into the school setting by teachers, school
psychologists, resource teachers, and speech therapists
(see Table 4). The majority of parents of children with
Prader-Willi syndrome (52%) and Williams syndrome (66.7%)
reported that they were the sole providers of
syndrome-related information in the classroom, in contrast
with only 9.5% of parents of children with Down syndrome,
[chi square] (2, N = 67) = 15.20, p < .001.
Discussion
As one of the first studies to examine parental
knowledge of etiology-related educational issues, this
study demonstrates the ways in which etiology-based
behavioral research has and has not been made available to
those shaping educational programs for children with
genetic mental retardation syndromes. Although researchers
have established important connections between genetic
syndromes and behavioral outcomes, such knowledge has only
partially reached parents. The study also sheds light on
the way that knowledge about certain syndromes seems
"ahead" of knowledge about others.
On the most general level, parents in this study of
chronological age-matched children seemed only partially
aware of well-established etiology-related behaviors.
Although parents of children with Down syndrome seemed
aware of their children's strong visual over verbal
processing abilities and relative weaknesses in expressive
language, parents in the other two groups rated their
children less in accord with their etiology-based
behaviors. To some extent, parents seemed informed about
the more visible features of their child's syndromes:
overeating and obsessive-compulsive behaviors in
Prader-Willi syndrome, visual processing strength and
verbal expression weaknesses in Down syndrome, and
musicality in Williams syndrome. Parents were not as aware
of some of the more subtle and complex cognitive features
associated with their children's syndromes. Parents of
children with Prader-Willi syndrome, for example, were not
aware of their children's simultaneous processing
strengths, and parents of children with Williams syndrome
did not report stronger verbal than visual processing
abilities in these children.
Even less connection to etiology seems apparent in the
supportive services provided for children with these three
syndromes. Children with Down syndrome, Prader-Willi
syndrome, and Williams syndrome all received similar
services--no connections to etiology-related strengths or
weaknesses were apparent. For example, even though children
with Down syndrome have marked language delays compared
with children in the other two groups, no differences were
observed in the amounts of speech therapy they received.
At the same time, however, the parent findings must be
considered in light of both the behavioral domain and the
specific etiology. In terms of behavioral domains, parents
in both the Prader-Willi and Williams syndrome groups were
aware of their children's troublesome maladaptive
behaviors. Parents of children with Prader-Willi syndrome
rated their children's overeating and obsessive-compulsive
behaviors at much higher levels than did the parents of
children with the other two syndromes. Similarly, parents
of children with Williams syndrome seemed somewhat aware of
their children's sensitivity to loud noises. Such attention
to behavior problems, though not present in every instance,
was usually present among parents of children in these two
groups.
A second qualifier of these findings concerns Down
syndrome. Compared to parents of children with Prader-Willi
or Williams syndromes, parents of children with Down
syndrome possessed more in-depth understandings of their
children's etiology-related behaviors. They were aware that
their children are better visual than auditory processors,
and that these children have relative weaknesses in verbal
expression. Even though almost all children with Down
syndrome (90.5%) were already receiving speech therapy, a
full 80% of such parents desired more speech-language
services for their children. Indeed, parents of children
with Down syndrome answered all etiology-related items in
the predicted ways. In contrast, parents of children with
the other two syndromes were primarily informed about their
children's maladaptive behaviors but were much less attuned
to their child's cognitive-linguistic profiles.
Several reasons might account for this "Down syndrome
advantage" in terms of parental knowledge. The first and
most obvious explanation concerns the relative
understanding of this syndrome by both the general public
and researchers. In contrast to both Prader-Willi syndrome
and Williams syndrome, Down syndrome is known to the public
through TV shows (Life Goes On) and popular books (e.g.,
Kingsley & Levitz, 1994); the syndrome also has several
large and active national and international parent
organizations. Even among researchers, Down syndrome is a
"known" disorder. For 140 years, researchers have examined
many of this disorder's genetic, physical, and medical
aspects (Pueschel, 1990); to this day, almost half of all
behavioral work featuring any genetic mental retardation
disorder includes individuals with Down syndrome as one of
its groups (Hodapp, 1996). In addition to being based on
fewer studies, the behavioral findings on Prader-Willi
syndrome, Williams syndrome, and other less well-known
disorders, although accumulating at a rapid rate, date
mostly to the late 1980s and 1990s (Dykens et al., 2000).
This general, long-standing awareness of Down syndrome
might also explain the findings concerning who brings
genetic information into the classroom setting. Compared to
Prader-Willi syndrome and Williams syndrome, parents of
children with Down syndrome are not the sole
etiology-oriented "information-providers" for the education
of their children. As shown in Table 4, parents of children
with Down syndrome are often joined by their children's
teachers, school psychologists, speech therapists, and
others in bringing information about Down syndrome into the
classroom. In contrast, many parents of children with
Williams and Prader-Willi syndromes find themselves the
sole providers of syndrome-related information, even though
they may not have access to a great deal of information.
Indeed, the link remains unclear between how much parents
and professionals know about etiology-related behaviors,
who brings such knowledge into the classroom setting, and
how educational practices change as a result.
As an early exploration of a complex topic, this study
also has certain methodological limitations that should be
noted. First, the samples were obtained through parent
groups and therefore may not reflect the larger populations
of families of children with these three syndromes.
Particularly with Prader-Willi and Williams syndromes,
families connected to the nationwide parent groups may be a
uniquely informed subset of parents of children with this
syndrome.
A second limitation is that some domains of processing
were difficult to describe in lay terms. For example, we
described sequential processing as "step-by-step learning"
and simultaneous processing as "learning well by being
given the big picture." Respondents, however, may have had
difficulty rating their children using these approximate
definitions. Also, although etiology-based behavioral
profiles are found in most children with particular
syndromes, individual children undoubtedly varied in the
degree to which they expressed the behavioral profiles
associated with these three syndromes (Dykens, 1995).
Future studies need to link children's performance on
various assessments of intellectual and maladaptive
behaviors to parent and teacher ratings.
Several additional issues remain to be discussed. First,
this article has implicitly adopted an approach that
supports Aptitude x Treatment interactions, or ATIs. Thus,
we have implicitly argued that children with one or another
specific behavior or pattern of behaviors might respond
better to one type of treatment versus another. To date,
researchers in both general and special education have not
always found such interactions.
Given this lack of evidence, some have argued that ATIs
should be abandoned as a special education approach
(Gresham & Witt, 1997; Lloyd, 1984). In contrast, others
have argued that ATI research has suffered from poor
conceptualization by researchers and the construction of an
ATI "straw man" that has been readily proven ineffective
(Speece, 1990). It may be that researchers have not yet
developed effective methods for uncovering ATIs, and there
may be factors that make existent ATIs difficult to
uncover.
A future direction for this line of research is to
translate syndrome-based profiles into specific educational
practices or guidelines. For example, research is needed on
the nature of the relative strength in visuospatial
processing in individuals with Down syndrome and how this
modal processing strength can be used to improve verbal
processing-dependent developmental outcomes, such as
language development. Such research could then be used to
tailor instructional approaches in weaker domains (i.e.,
language acquisition) for individuals with Down syndrome
and tested for efficacy in classrooms and other special
education settings.
This study begins the process of examining the degree to
which etiology-related behavioral information is known to
parents and used in the educational setting. At this point,
the picture seems mixed. Etiology-related behavioral
problems seem more salient to parents than
cognitive-linguistic strengths and weaknesses. According to
parental report, their children's educational services are
generally not attuned to etiology-related
cognitive-linguistic profiles or behavior problems. And
yet, if the example of Down syndrome information is
instructive, many people--both parents and
professionals--may soon bring etiology-related information
to the classroom. Indeed, as behavioral information becomes
better known to parents, teachers, and other service
providers, more targeted, successful etiology-based
instructional accommodations can be developed for children
with many different genetic mental retardation disorders.
TABLE 1. Demographic Variables for Children and Parents in
the Three Groups
Item DS PWS WS F or [chi square]
Children's age in years
M 11.35 12.19 12.76
SD 5.23 3.98 4.15 .51
Children's gender
Boys 12 11 9
Girls 9 14 12 .58
Level
Borderline 0% 0% 0%
Mild 45.0% 81.8% 66.7%
Moderate 50.0% 18.2% 28.6%
Severe 5.0% 0.0% 4.7% 6.71
Respondents' gender
Men 21 21 20
Women 0 4 1 4.56
Mothers' education in years
M 15.10 15.21 14.65
SD 2.02 2.32 3.21 0.28
Fathers' education in years
M 15.37 15.48 15.10
SD 3.14 2.08 2.71 1.71
Child placement
General education 14.3% 28.0% 19.0%
Mainstreamed 47.6% 28.0% 38.1%
Special education 38.1% 44.0% 42.9% 5.49
Note. All F's and [chi square] values are nonsignificant. DS = Down
syndrome; PWS = Prader-Willi syndrome; WS = Williams syndrome.
TABLE 2. Percentage of Participants in Each Group Receiving, and
Desiring More of, Each Service
% Receiving service
Etiology DS PWS WS [chi square]
Speech 90.5 76.0 71.4 2.54
Physical 19.0 16.0 38.1 3.46
Occupational 23.8 16.0 52.4 7.75 *
Reading 23.8 28.0 42.9 1.98
Writing 23.8 32.0 38.1 1.00
Math 23.8 24.0 42.9 2.47
Adaptive P.E. 71.4 56.0 76.2 2.36
Aide 47.6 72.0 71.4 3.65
Social skills 57.1 52.0 28.6 3.97
Psychological counseling 19.0 8.0 28.6 3.31
One-on-one 19.0 40.0 38.1 2.65
% Desiring more of service
Etiology DS PWS WS [chi square]
Speech 80.0 40.0 23.5 12.91 **
Physical 26.3 40.0 41.2 1.14
Occupational 55.0 52.0 27.8 0.18
Reading 60.0 40.0 26.3 4.63
Writing 55.0 40.0 21.1 4.73
Math 40.0 40.0 36.8 0.06
Adaptive P.E. 26.3 60.0 41.2 1.14
Aide 10.0 16.0 50.0 11.62 *
Social skills 47.6 48.0 60.0 0.83
Psychological counseling 15.8 44.0 38.9 4.12
One-on-one 25.0 32.0 52.6 3.51
Note. DS = Down syndrome; PWS = Prader-Willi syndrome: WS = Williams
syndrome.
* p < .05. ** p < .01.
TABLE 3. Parental Behavior Ratings About Their Children with Down
Syndrome, Williams Syndrome, and Prader-Willi Syndrome
DS WS
Behavior M SD M SD
Verbally expressive 2.70 1.45 4.24 1.22
Visual learner 4.20 0.89 3.65 1.18
Auditory learner 2.90 0.07 3.80 1.10
Learns through music 3.75 0.85 4.09 0.94
Needs material broken down into steps 3.90 1.02 4.52 0.92
Learns well by being given
"the big picture" 2.80 1.15 2.47 1.03
Frightened by loud noises 3.25 1.55 3.57 1.56
Overeats 2.50 1.35 1.52 1.03
Needs things "just right" 3.10 1.48 2.05 1.07
PWS
Behavior NJ SD F
Verbally expressive 4.04 1.05 9.41 ****
Visual learner 4.13 0.95 1.73
Auditory learner 2.83 0.91 7.05 **
Learns through music 3.00 1.44 5.62 **
Needs material broken down into steps 4.44 0.91 2.61
Learns well by being given
"the big picture" 2.96 1.30 0.98
Frightened by loud noises 1.68 0.98 12.72 ****
Overeats 4.00 1.29 23.53 ****
Needs things "just right" 3.64 1.41 8.24 ***
Behavior Group differences
Verbally expressive PWS, WS > DS
Visual learner
Auditory learner WS > DS, PWS
Learns through music WS > PWS
Needs material broken down into steps
Learns well by being given
"the big picture"
Frightened by loud noises WS, DS > PWS
Overeats PWS > DS > WS
Needs things "just right" PWS > DS > WS
Note. DS = Down syndrome; PWS = Prader-Willi syndrome; WS = Williams
syndrome.
** p < .01. *** p < .001. **** p < .0001.
TABLE 4. Percentages of Individuals Who Bring
Syndrome-Related Information to the Classroom
DS PWS WS
Individuals (%) (%) (%) [chi square]
Parents 85.7 96.0 95.0 1.99
School psychologist 66.7 4.0 .0 33.96 ****
Teacher 61.9 24.0 10.0 13.86 ***
Speech therapist 42.9 4.0 5.0 15.22 ****
Resource teacher 28.6 8.0 .0 8.49 *
Pediatrician or other MD 23.8 16.0 .0 5.12
Physical therapist 14.3 0.0 10.0 3.57
Occupational therapist 9.5 0.0 .0 4.42
Note. DS = Down syndrome; PWS = Prader-Willi syndrome; WS = Williams
syndrome.
*** p < .001. **** p < .0001.
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Institute
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