Published in The Analysis of Verbal Behavior, 2004
Abstract
This paper analyzes autism as a contingency-shaped disorder of
verbal behavior. Contingencies of reinforcement in effect during
the first to third year of a child's life may operate to establish
and maintain those behaviors that later result in a diagnosis of
autism. While neurobiological variables may, in some cases, predispose
some children to be more or less responsive to environmental variables
than others, our analysis suggests that reliance on neurobiological
variables as causal factors in autism is unnecessary. We present
six paradigms that may play critical etiologic roles in the development
of behaviors labeled as autistic. Recognizing these contingencies
and their resulting behaviors during the first two years of a child's
life may contribute substantially to earlier identification, more
effective treatment and, quite possibly, to the development of Applied
Behavior Analysis programs for the prevention of autism that could
be implemented immediately. Conceptualizing autism as a contingency-shaped
disorder of verbal behavior may provide a new and potentially more
effective paradigm for behavioral research and treatment in autism.
An Analysis of Autism as a Contingency-Shaped Disorder of Verbal
Behavior
Autism is widely regarded
as one of the most severe of childhood behavioral disorders (Barton-Cohen,
Allen, & Gillberg, 1992).
The effects of autism are pervasive and interfere with the acquisition
of normal behavior repertoires across almost every area of human
functioning. During the past 30 years extensive research has been
devoted to the development and implementation of effective behavioral
treatments and to an analysis of the etiology of autism. Since Lovaas
(1987) demonstrated that it is possible to achieve relatively total
recovery in some young children diagnosed with autism by using an
intensive 40-hour-per-week behavioral intervention, significant progress
has been made in the behavioral treatment of children diagnosed with
autism. These treatments have for the most part relied on a functional
analysis of behaviors that are labeled as autistic (Charlop-Christy, & Kelso,
1997; Maurice, Green, & Foxx, 2001; Maurice, Green, & Luce,
1996; Leaf, & McEachin, 1999; Lovaas, 1977, 1981; Sundberg, & Partington,
1998).
Despite substantial progress
in the treatment of autism, determining the etiology of those behaviors
that may later result in a diagnosis of autism continues to be
an unresolved issue. The Advocate (2002, p. 6) reported that statistics
recently released by the Autism Society of America stated that
autism is increasing at a rate of 10 to 17 % per year. As a result
there has been a strong advocacy for a substantial increase in
research into the causes of autism. Discovering the cause of autism
is considered by many professionals and autism advocates as essential
in the development of more effective programs for the prevention
and treatment of autism. Lee Grossman, President of the Autism
Society of America, and Robert Beck, Executive Director, recently
stated (2002), "After more than 50 years of study, no causes
have been identified. There needs to be a geometric increase in research
funding . . . to determine the causes of autism" (p. 7).
Currently there are at
least two major hypotheses regarding the causes of autism, those
that are primarily neurobiological and those that are primarily
behavioral. The neurobiological hypothesis attributes the cause
of autism to a presumed but as yet unidentified neurobiological
disorder. Conversely, behavioral theories of autism describe how
environmental contingencies operating during the first one to three
years of a child's life may establish and maintain those behaviors
that later result in the diagnosis of autism.
This paper presents a
behavioral analysis of the etiology of those behaviors upon which
a diagnosis of autism is based. Our analysis suggests that reinforcement
contingencies operating during the first to third year of a child's
life may play a substantial role in the development of the behaviors
that are subsequently diagnosed as autism. We have previously published
an analysis of contingencies of reinforcement that may lead to
delay in acquisition of verbal behavior in typical young preschool
children (Drash & Tudor, 1990, 1993). A similar
analysis may also be applied to the shaping of behaviors that result
in the diagnosis of autism (Drash, High, & Tudor, 1999; Drash & Tudor,
1999, 2000).
We recognize that the prevailing opinion among many professionals
and parents, including many behavior analysts, is that a disorder
as severe and debilitating as autism could only occur through defective
neurological or biological mechanisms. We understand and respect
their opinions. Moreover, we do not propose that this analysis represents
the only possible explanation for the occurrence of behaviors that
result in the diagnosis of autism. We do not rule out the possibility
that, in the future, researchers may discover specific neurological,
biological or genetic factors that may contribute directly to the
development of behaviors that later result in a diagnosis of autism.
However, a behavioral analysis of the cause of autistic behaviors
is in no way dependent upon the presumption of such factors.
Our goals are identical to those of parent advocates and other
professionals who call for more effective procedures for prevention,
treatment, and possible cure of autism that can be implemented immediately.
Our operating assumption is that a behavioral analysis of the contingencies
that may shape those behaviors upon which a diagnosis of autism is
based will ultimately serve the best interests of children diagnosed
with autism and their families. We believe that, in the long term,
this analysis of autism as a contingency-shaped disorder of verbal
behavior may contribute materially to the development of more effective
behavioral programs for prevention, early intervention, and treatment
of autism that will, in the future, benefit hundreds, and perhaps
thousands, of young children and their families.
The Neurobiological View of the Causes of Autism
Many contemporary theories of autism have linked its cause to as
yet unidentified neurological or biological factors. In support of
this position, Minshew, Sweeney, and Bauman (1997) in the Handbook
of Autism and Pervasive Developmental Disorders (Cohen & Volkmar,
1997) stated, "Autism is now generally accepted to be a disorder
of brain development and hence of neurological origin" (p.344).
Similarly in the same volume Dykens and Volkmar (1997) stated, "Researchers
generally agree that autism is the result of some neurobiological
factor or factors" (p.388). These popular assumptions about
the causes of autism have spawned at least three national organizations
devoted to discovering medical, neurological, or biological causes
of autism: Cure Autism Now (CAN); Defeat Autism Now! (DAN!); Autism
Research Institute, and the National Alliance for Autism Research.
Although neurobiological views of the causes of autism are intuitively
appealing, medical research has failed to provide conclusive evidence
for a neurological, biological, or genetic cause for autism. In the
introduction to a special issue of the Journal of Autism and
Developmental Disorders devoted to contemporary research in
autism Alexander, Cowdry, Hall, and Snow (1996) stated, "No
consensus regarding causes or potential cures for autism is assumed.
This is a problem that is not yet solved" (p. 118). Likewise,
Bailey, Phillips, and Rutter (1996) stated, "a replicable, neurophysiological
basis for autism has not yet been identified" (page 89). More
recently other neurobiological researchers have reached similar conclusions.
Lauritsen, Mors, Mortensen, and Ewald (1999) stated, "Infantile
autism is a heterogeneous disorder of unknown etiology" (p.335).
Trottier, Srivastava, and Walker (1998) reported, "The etiology
of autism is complex, and in most cases the underlying pathologic
mechanisms are unknown" (p. 103). Thus despite the prevalence
of the neurobiological explanation, it is evident that no conclusive
scientific evidence for a neurobiological cause for autism currently
exists.
Behavioral Theories of Autism
Behavior analytic explanations of the causes of autism are numerous
and diverse. These include the behavioral hypothesis of Ferster
(1961), the contingency-shaped or behavioral incompatibility theory
of Drash and Tudor (1993, 1999, 2000), the behavioral mismatch theory
of Lovaas and Smith (1989), the social communication theory of Koegel,
Valdez-Menchaca, and Koegel (1994), the stimulus control theory of
Spradlin and Brady (1999), and the behavioral interference theory
of Bijou and Ghezzi (1999). These behavioral theories all incorporate
the view that the behaviors of children labeled as autistic can be
analyzed in terms of the concepts and principles of Applied Behavior
Analysis (ABA), and that these concepts and principles can produce
effective treatment programs for children diagnosed with autism (Ghezzi,
Williams, & Carr, 1999). However, these theories differ greatly
with regard to the initiating cause of behaviors upon which a diagnosis
of autism is based.
With the exception of
the first two theories (Drash & Tudor,
1993, 1999, 2000; Ferster, 1961) these behavioral theories attribute
the initiating cause of autism to a defective neurological or biological
process that interferes with the normal developmental process. Lovaas
and Smith (1989) postulate a mismatch between the normal environment
and the nervous system of the child. The Koegel, Valdez-Menchaca,
and Koegel (1994) theory postulates a defective neurological process
that may result in inappropriate socialization and defective language
development. Spradlin and Brady (1999) hypothesized that possible
neurological limitations in children with autism make it more difficult
to establish stimulus control. Bijou and Ghezzi (1999) postulated
that young children with autism have "abnormalities in their
sensory equipment" that produce a "tendency to escape and
avoid tactile and mild auditory stimuli" (p. 34). This avoidance
behavior then interferes with normal social and language development.
These four theories can be termed reductionistic in that
they attribute the initiating cause of autism to an hypothesized
but unidentified neurobiological process. In contrast to these, only
Drash and Tudor (1993, 1999, 2000) and Ferster (1961) rely on a completely
behavioral analysis that attributes the early development of autistic
behaviors to specific and identifiable contingencies of reinforcement
in the early environment of the child.
One of the first sign ificant behavioral analyses of autism was
published by Ferster (1961). He presented a detailed analysis of
how a variety of contingencies of reinforcement operating between
parent and child during the early years might establish and strengthen
a repertoire of behaviors typical of children diagnosed as autistic.
He observed that a child's disruptive behaviors may be maintained
by their effect on his parents or caregivers because they function
as an aversive stimulus that can be terminated if the caregiver supplies
a reinforcer. Moreover, he also observed that over time such aversive
behaviors may be strengthened by continued reinforcement and become
prepotent over other age-appropriate behaviors. Unfortunately, Ferster's
analysis was regarded by some as a behavioral version of the discarded
psychogenic theory which ascribed autism to parental personality
traits. The implications of the article for research and treatment,
including extensions to the communicative functions of aberrant behavior,
therefore, were never fully analyzed.
In a review of the Bijou
and Ghezzi (1999) analysis, Hayes (1999) cautioned that attributing
psychological events to biological causes is unnecessary and is
an impediment to the development of effective (behavioral) treatments
since it leaves lingering doubt as to the possibility of truly
successful psychological intervention. Likewise, Schlinger (1995) stated
that behavioral or environmental contingencies that might account
for a behavioral complex should be ruled out first before attributing
the behavior to neurological, biological, or genetic causes.
Categories of Behavior that Require Analysis if Autism
is to be Conceptualized as a Contingency-Shaped Disorder
The Diagnostic and Statistical Manual of Psychiatric Disorders (DSM
IV), (American Psychiatric Association, 1994) outlines three specific
categories of behavior that are considered essential for an accurate
clinical diagnosis of autism. Since there is no neurobiological or
genetic test for autism, the diagnosis of autism is based entirely
on observed behavior. Based on our research and that of others we
have included a fourth category of behavior that we consider a central
feature of autism.
In order to demonstrate that behavioral contingencies may be largely,
if not completely, responsible for the behavioral complex diagnosed
as autism, it is necessary to analyze how contingencies of reinforcement
may establish, shape, and maintain the behaviors that comprise each
of these four categories of behavior.
Qualitative Impairment in Communication as Manifested by Little
or No Spoken Language
Severe language deficiency is a classic feature of autism (Churchill,
1978; Richter, 1978; Rutter, 1974, 1978). Autism in young children
is rarely diagnosed in the absence of a significant deficiency in
spoken language. Indeed, it is the lack of age-appropriate spoken
language at age 2 to 3 years that typically initiates the entire
referral, diagnostic, and treatment process. Many children diagnosed
with autism at 2 to 3 years of age have little or no expressive or
receptive verbal behavior, while others have minimal receptive repertoires
but no expressive verbal behavior. Many 2 and 3-year-old children
when first diagnosed with autism are functioning at a 9 to 12 month
level of language acquisition. Thus, serious deficiency in or
lack of spoken language repertoires may be the primary and essential
distinguishing characteristic of autism, since without deficiency
in spoken language such children quite probably would not be diagnosed
as autistic.
Qualitative Impairment in Social Interaction Including Marked
Social Isolation and Impairment in Peer Relationships
Social isolation and delay in age-appropriate social behavior is
a second major category of behavior typical of children with autism.
Almost all children diagnosed with autism have some deficits or impairment
in their social repertoires. Behaviors in this category include social
isolation and aloneness, avoidance of eye-contact, lack of age-appropriate
social play, lack of responsiveness to other persons, and lack of
age-appropriate social-interactional skills.
Markedly Restricted, Repetitive, and Stereotyped Patterns of
Behavior, and Limited Responsiveness to Environmental Stimuli
This category includes behaviors such as stereotyped body movements,
hand flapping, persistent preoccupation with specific parts of objects,
emotional responses to inconsequential alterations in trivial aspects
of the environment, unreasonable insistence on following specified
routines in precise detail, preoccupation with specific responses,
such as smelling or spinning objects. The range and variety of environmental
stimuli that function as reinforcers is also markedly restricted.
Moderate to Severe Disruptive Behaviors, Task-Avoidance, and
Noncompliance
Disruptive behaviors,
task-avoidance, and noncompliance are not specified as distinct
diagnostic criteria for autism in the DSM IV. However, we view
these behaviors as both typical and critical components in most
cases of autism. Moreover, in his original papers on autism, Kanner
listed a variety of disruptive behaviors including temper tantrums,
aggressiveness, and destructiveness as characteristic of children
with autism (Frith, 1991). There is also overwhelming evidence
in the research literature on autism that documents that challenging
behaviors are highly typical of children labeled as autistic (Carr & Durand,
1985, 1986; Charlop-Christy & Kelso, 1997; Durand, 1999; Iwata,
Dorsey, Slifer, Bauman, & Richman, 1994; Leaf & McEachin,
1999; Lovaas, 1993; Repp, & Singh, 1990). Typical behaviors in
this category include crying, screaming, temper tantrums, head-banging,
kicking, biting, task-avoidance, non-responsiveness, noncompliance,
aggressive behavior, self-stimulatory behavior, and self-injurious
behavior.
How Contingencies of Reinforcement May Operate to Establish and
Shape the Behaviors that Subsequently Result in a Diagnosis of Autism.
In summarizing their interference theory of autism, Bijou and Ghezzi
(1999) concluded, ". . . most of the abnormal
behaviors of children with autism serve to compensate for their deficiencies
in social-emotional and verbal behavior" (pp. 39-40). Based
on their analysis,deficiencies in social-emotional
behavior and verbal behavior are alone sufficient to account
for most of the behaviors that are observed in children labeled as
autistic. While agreeing with much of their analysis, we differ substantially
in at least three respects.
First, we view autism primarily as a contingency-shaped
disorder of verbal behavior that often coexists with a repertoire
of avoidance and other disruptive behaviors. In order
to analyze the causes of autism, it is first necessary to analyze
the causes of deficiency in verbal behavior. As will be discussed
below, the social-emotional deficits of children with autism can
be causally linked by a behavioral analysis to the deficiencies
in verbal behavior and the presence of disruptive avoidance behaviors.
Second, we view the presence of inappropriate verbal
behavior, that is, aversive vocal manding (e. g., screaming, crying
or whining) in combination with avoidance and other disruptive
behaviors, rather than age-appropriate verbal behavior (such as,
pre-speech vocal sounds, words, phrases, etc.) as primary causal
factors contributing to the shaping and maintenance of other behaviors
on which a diagnosis of autism is based. Both experimental
and clinical evidence details how repertoires of aversive vocal
manding and other disruptive avoidance behaviors can be shaped
by reinforcement contingencies, and once established, are incompatible
with the acquisition of functional verbal behavior (Drash, 1993;
Drash, High, & Tudor, 1999; Drash & Tudor, 1993, Richter,
1978). Moreover, since many of these more aversive behaviors terminate
parent-child interactions, they may also prevent or inhibit the
establishment of social-emotional bonding and other social behaviors.
These two repertoires, aversive vocal manding and other disruptive
behaviors, may thus be responsible for most of the other behavioral
symptoms of autism.
Third, absence of age-appropriate verbal behavior
and the presence of avoidance behavior can be explained as a result
of contingencies of reinforcement operating during the first to
third year of a child's life, especially during the first 12 to
18 months. A behavioral analysis of those contingencies
explains the development or lack of development of verbal behavior
and the presence of disruptive and avoidance behavior without relying
on hypothetical neurological variables to explain their occurrence.
The fact that there may
be subsets of children diagnosed as autistic with accompanying
neurological, biological, or genetic abnormalities is not disputed.
This would not be incompatible with our contingency-shaped theory.
Since the diagnosis of autism is based entirely on a continuum
of observed behaviors, i. e., "autism spectrum disorders" (Wetherby & Prizant,
2000), the diagnosis will, on occasion, almost inevitably include
subsets of atypical children, who in addition to their principle
disorder, such as Down syndrome, Fragile X syndrome, or Rett's disorder,
may also display behaviors that are typical of children diagnosed
as autistic. In other cases, children diagnosed with autism may later
be found to have seizures, brain tumors, or other physiological problems
which may have contributed to the development of autistic behaviors.
Basic Premises of a Behavioral Analysis Of Autism as a Contingency-Shaped
Disorder of Verbal Behavior
To analyze autism as a contingency-shaped disorder of verbal behavior
it is necessary to provide a conceptual analysis showing how reinforcement
contingencies may establish and maintain a repertoire of deficient
verbal behavior and disruptive avoidance behaviors during the first
one to two years of life.
The purpose of this paper is to present a conceptual analysis that
extends well established behavioral principles to an analysis of
the etiology of behaviors that are later diagnosed as autistic. All
of the terms of this analysis refer to potentially modifiable conditions
in the child's environment and directly observable and measurable
aspects of his performance. Moreover, experimental evidence supports
each of the basic premises of this analysis. There are at least four
major premises upon which this analysis is based. In summary, these
are: 1) The acquisition of verbal behavior, or the lack thereof,
by children labeled as autistic is primarily a function of reinforcement
contingencies provided by caregivers and others during the first
years of a child's life. 2) Caregivers and others may inadvertently
shape repertoires of disruptive and avoidance behaviors in their
infants and young children during the first one to three years of
a child's life. 3) Disruptive and task-avoidance responses are frequently
present in young children diagnosed with autism, or PDD. 4) When
present, disruptive behaviors may become incompatible with and may
prevent the acquisition of age-appropriate verbal behavior, as well
as other social behaviors.
The first question is whether and to what degree contingencies
of reinforcement provided by caregivers and others may facilitate
or impede the language acquisition of their children. Empirical support
for the concept that parents strongly influence the language acquisition
of their children from infancy forward is provided by the longitudinal
research of Hart and Risley (1995, 1999) on language development
in children from 7 months to 3 years. Their research shows that the
frequency and complexity, or lack thereof, of the child's
verbal behavior at age 3 years is directly related to the frequency
and complexity of verbal behavior that occurs between parents and
their children from the first year of life forward. When the hourly
frequencyof talk between parent and child was high,
the children developed large vocabularies and spoke in complex sentences
by age three. When the hourly frequency of talk between parent and
child was low, children developed much smaller vocabularies and spoke
in much less complex sentences. This finding suggests that if there
is very little or no interactive talk between parent and child during
the first year to three years, the child's verbal behavior may be
deficient at three years.
In keeping with our premise
that acquisition of verbal behavior is a function of contingencies
of reinforcement, Hart and Risley (1999) concluded, "We propose that language development is governed
by the same natural laws as motor, social, and cognitive development" (p.
199).
The second question is
whether caregivers and others, during the first year of a child's
life, may unintentionally shape disruptive infant response repertoires.
In a series of experimental studies of emotional behavior of infants,
ages 6 to 12 months, and their parents, Gewirtz and Pelaez-Nogueras
(1991, 1999) demonstrated that disruptive infant behaviors, such
as crying, whining, and screaming, can be inadvertently shaped
by parents during the first year of life. Moreover, the parent-infant
contingencies that shape the disruptive behaviors can be identified
and modified as early as 6 to 9 months of age. In discussing how
disruptive infant behaviors may be shaped, they concluded, "The infant adaptive problem behaviors actually
appear to be operants under the control of occasioning stimuli and
consequences inadvertently provided . . . by the responding of well-intentioned,
loving parents" (1999, p. 272). Thus, without intending to do
so, parents may shape disruptive behaviors during the first year
of life which may interfere with the acquisition of more adaptive
responses.
The third question is whether disruptive and task-avoidance responses
are frequently present in young children diagnosed with autism, or
PDD. We have previously shown that aversive manding and other disruptive
avoidance behaviors are frequently present in young children diagnosed
with autism or PDD. An analysis of all cases (N = 48) admitted during
1992 and 1993 with a diagnosis of autism or PDD, revealed that in
41 of the 48 cases, or in 85% of the cases, disruptive or task-avoidance
behavior was present and was a major factor interfering with acquisition
of verbal behavior (Drash, 1993).
The final question is
whether it is possible for aversive manding and other disruptive
behaviors, when present, to prevent the acquisition of verbal behavior.
We have shown that aversive manding and other avoidance behaviors
when present may be incompatible with the acquisition of age-appropriate
verbal behavior. It is only after inappropriate verbal behavior
and other disruptive behaviors are greatly reduced or eliminated
by providing reinforcement only for acceptable vocal mands (that
is, extinction combined with differential reinforcement of acceptable
vocal mands), that shaping of appropriate vocal mands can proceed.
(Drash, High, & Tudor, 1999).
The contingency-shaped theory of autism is based entirely on behaviors
that are readily observable, measurable, and modifiable, and the
analysis is thus subject to further experimental analysis and verification.
When do Contingencies of Reinforcement Begin to Shape the Behaviors
that are Later Diagnosed as Autistic?
Until recently the diagnosis
of autism was rarely made before a child was 2 to 3 years of age.
Despite this, accumulating evidence suggests that many parents
have expressed concern to their pediatrician about their child's
language and social delay by 18 months of age (Siegal, Pliner,
Eschler, & Elliot, 1988). Other research reported
that 50% of parents of a child diagnosed as autistic suspected a
problem before their child was 1 year old (Ornitz, Guthrie, & Farley,
1977). Barton-Cohen, Allen, and Gillberg (1992) demonstrated that
behaviors that are correlated with a later diagnosis of autism can
be accurately identified at 18 months. More recent research has shown
that behavioral correlates of a later diagnosis of autism can be
identified as early as 8 months (Werner, Dawson, Osterling, & Dinno,
2000) to 12 months (Osterling & Dawson, 1994).
The fact that behaviors correlated with a later diagnosis of autism
can be detected as early as 8 to 12 months, in combination with parental
awareness and concern over developmental problems before a child
is 12 months old, suggests that the contingencies producing language
and social delays are in all likelihood operating during the first
year of life, and quite possibly as early as 6 to 8 months, if not
earlier. Therefore, a behavioral analysis should focus on pinpointing
those caregiver-infant interactions that may establish and reinforce
aversive vocal mands and other disruptive and avoidance behaviors
that occur during the first year of life and that may later result
in a diagnosis of autism. The contingencies and resulting behaviors,
to be described below, in all likelihood, have their origins during
the first year and are then further shaped, refined, and strengthened
as the child develops.
The Relationship Between Manding and Verbal Delay in Young Children
Labeled as Autistic
Skinner's (1957) analysis of verbal behavior is particularly relevant
to analyzing verbal deficiency in young children labeled as autistic.
Skinner's analysis indicates that verbal behavior is acquired primarily
because it produces reinforcement through the mediation of other
persons. Skinner's (1957) identification of the mand as the first
verbal operant to be acquired is particularly critical to our analysis.
If during the first year to three years of life an infant is given
all the essential, life sustaining reinforcement and nurture without
a requirement for age-appropriate vocal manding, then it is quite
possible that verbal behavior may not develop. A detailed description
of how Skinner's analysis of verbal behavior can be applied to the
analysis and treatment of verbal behavior in children diagnosed as
autistic is provided by Sundberg and Michael (2001) and Sundberg
and Partington (1998).
Reinforcement Paradigms that May Contribute to the Development
of Deficient Verbal Repertoires in Children with Autism
In a previous publication
we presented an analysis of reinforcement contingencies that may
contribute to language delay in young preschool children (Drash & Tudor, 1990, 1993). Our research has demonstrated
that a similar analysis applies equally well to language delay in
young children with autism (Drash, High, & Tudor, 1999; Drash & Tudor,
1999, 2000).
There are at least six
reinforcement paradigms that may contribute to significant deficiency
in verbal behavior that we have identified and analyzed in our
verbal behavior research with children labeled as autistic over
the past thirty years. The observations upon which these analyses
are based represent multiple replications of within-subject studies
in which the contingencies preventing acquisition of verbal behavior
were repeatedly identified and analyzed, and then systematically
replaced with contingencies that produced age-appropriate verbal
behavior. Our standard data collection system for continuous recording
and analysis of verbal behavior during the shaping of verbal behavior
has been previously described (Drash & Tudor, 1991). This data
recording system allowed us to meet the requirements for drawing
valid inferences from within-subject case studies, replicated across
multiple subjects, as discussed by Kazdin (1982).
Each of these six reinforcement paradigms may contribute to the
establishment of a repertoire of behavior that is incompatible with
the acquisition of age-appropriate verbal behavior. Several of these
paradigms may concurrently create a repertoire of avoidance responses.
1. Reinforcement for Aversive Vocal Manding, such as Crying or
Screaming, or Other Avoidance Behaviors that May Be Incompatible
with Acquiring Age-Appropriate Verbal Behavior
Manding is the first
type of verbal behavior emitted by infants (Drash, High, & Tudor, 1999; Drash & Tudor, 1993; Schlinger,
1995; Skinner, 1957). The first cries of an infant are respondent
in nature and gradually come under operant control as vocal mands
when a caregiver responds to these cries. In most instances, the
infant's cries and screams are transformed into more acceptable verbal
behavior through the parent's subtle shaping and a variety of prohibitions
against screaming, crying or fussing (Bruner, 1983; Hart & Risley,
1995; Schlinger, 1999). Conversely, if caregivers inadvertently provide
reinforcement for crying, fussing, or screaming to the exclusion
of requiring age-appropriate vocal mands, a strong repertoire of
aversive vocal manding may be established (Ferster, 1961). For example,
if the parent has heard the infant produce the sound, "bababa" on
multiple occasions, the parent may prompt the child to say "baba" for
bottle by presenting the bottle with the verbal prompt, "Say, bababa." However,
if the child has been without food for some time, the response might
be a cry or scream, the response that in the past has been reinforced.
To escape the aversive crying of the infant, the parent may quickly
present the bottle without first requiring an echoic response to
the prompt. The infant's likelihood of crying in response to future
prompts for vocal behavior will have been further strengthened. Over
a longer period of time the caregiver may completely avoid the aversive
cries of the infant by providing food, milk, and other reinforcers
without first requiring appropriate vocal responses. The aversive
vocal manding of the child can interfere with and ultimately terminate
the parents' language teaching efforts and thereby prevent the acquisition
of age-appropriate verbal behavior.
After the contingencies
have shaped a strong repertoire of aversive vocal manding, stimulus
control over these responses will be present. The child will show
an increased tendency to emit aversive vocal mands and other avoidance
behaviors in situations similar to those that were previously reinforced.
For example, the child might pull the parent to the refrigerator
and wait to be given juice or milk. If the parent attempts to require
that the child first say "juice" or "milk," the
child may cry or scream until given the juice. The teaching efforts
are thus terminated, and aversive manding is further strengthened.
The majority of young children in our research and clinical programs
have had behavioral repertoires that reflect the influence of this
paradigm. An analysis of all cases (N = 48) admitted for treatment
with a diagnosis of autism or PDD during 1992-1993 revealed that
85% had disruptive or task-avoidance behavior that interfered with
acquisition of age-appropriate verbal behavior (Drash, 1993). Typical
of children in this category is a 3 1/2-year-old child referred for
treatment because of severe language delay. The initial evaluation
showed that the child produced no words or other age-appropriate
verbal behavior, and he emitted severe oppositional behavior. During
the initial evaluation he screamed loudly when prompted to produce
a word or sound. Twenty seven percent of his initial responses were
either screams or task-refusals. The mother reported that at home
whenever she prompted the child to produce a word or sound, the child
screamed until she ceased prompting him for vocal behavior.
A second child, who was first diagnosed as at-risk for autism at
15 months of age, engaged in similar behaviors. When evaluated by
us at 3 years of age, he had no expressive verbal behavior, and his
mother reported that he only communicated by screaming. Fifty percent
of his baseline responses were either screams or task-refusals. Temper
tantrums were his predominant response when he did not immediately
obtain a reinforcer. During the initial interview he began violently
kicking his mother. She reported that his tantrums often consisted
of pinching, kicking, scratching, biting, and head-butting. A speech
therapist who began therapy with the child at 18 months discontinued
structured therapy as a result of these disruptive behaviors.
As demonstrated by both cases, a single vocalization, the aversive
vocal mand, a cry or scream, functioned as a generic, all-purpose
mand that the child emitted to obtain reinforcement or to escape
or avoid aversive stimuli. The aversiveness of the child's behavior
discouraged parental attempts to teach more appropriate verbal behavior.
There are other vocal behaviors that, while not as aversive, are
functionally equivalent to aversive manding in that they are incompatible
with and prevent the acquisition of age-appropriate vocal behaviors.In
one instance, a 2 1/2-year-old child with a diagnosis of aphasia
was referred for the treatment of language delay. Although the child
had no age-appropriate expressive verbal behavior, he could produce
a variety of vocal sounds. But when prompted to produce an echoic
response, he primarily emitted one sound, "eee." The parents
were originally amused by this response and inadvertently reinforced
it, but they soon realized that the child vocalized few other sounds.
The predominance of the single sound "eee" prevented the
parents from teaching the child age-appropriate vocal behavior. It
was only after this single sound was replaced with other more appropriate
vocal mands through verbal behavior therapy that the child began
to acquire age-appropriate verbal behavior.
After a repertoire of aversive or competing vocal mands is established,
it can be extremely resistant to modification. In each of the above
cases, a repertoire of aversive manding or other incompatible vocal
behaviors effectively prevented acquisition of a repertoire of age-appropriate
vocal mands. In addition, these aversive behaviors may also prevent
or inhibit the establishment of social-emotional bonding and other
social behaviors. For a further discussion of this reinforcement
paradigm see Malott, Malott and Trojan (2000, pp. 295-298).
2. Reinforcement for Gestural Manding and Other Nonvocal Forms
of Manding
This category includes
behaviors such as looking at, reaching toward, pointing to, standing
next to, or pulling the caregiver toward the desired item. During
our standard clinical interview we routinely ask parents of children
labeled as autistic the following question, "Since
your child cannot talk, how do you know what he or she needs or wants?" The
most frequent response is that their child looks at, reaches toward,
or pulls them to the desired object. Caregivers routinely reinforce
and strengthen a repertoire of nonvocal gestural manding by
supplying reinforcing stimuli without first setting a contingency
for acceptable vocal mands (Drash, High, & Tudor, 1999). If the
reinforcing stimulus item is not immediately forthcoming, the child
may respond with crying or screaming until the parent presents the
reinforcer. If the parents believe that their child is unable to
speak, they may immediately provide a reinforcer, thus combining
the effects of paradigms one and two. If nonvocal gestural manding
continues to be reinforced until a child is three to four years,
it will become deeply ingrained and pervasive in the child's repertoire.
This nonvocal repertoire becomes the child's primary mode of obtaining
reinforcement, thereby preventing the acquisition of age-appropriate
verbal behavior.
3. Anticipating the Child's Needs and Thus Reinforcing a Repertoire
of Nonresponding that Prevents both Vocal and Nonvocal Mands
Although similar in some
respects to paradigm number two, a significant difference exists.
In this paradigm, caregivers anticipate the child's "needs
and wants" and deliver reinforcement noncontingently before
the child mands either vocally or gesturally. This paradigm
may over time establish a repertoire of very low rate behavior in
which the child simply waits passively for reinforcement without
any form of manding, either vocal or gestural. Therapeutic attempts
to prompt vocal behavior often produce temper tantrums or other forms
of task-avoidance.
Several parents reported
that they anticipated their child's needs to prevent their child
from becoming "frustrated." For
example, the parents of a 2 1/2-year-old nonverbal child reported
that they anticipated all their child's needs and never required
him to speak. They were unaware that by providing noncontingent reinforcement
they were strengthening a repertoire of nonresponding.
Over time this paradigm
may produce a silent or passive child who "appears
to have little or no interest in the environment," a characteristic
typical of many children labeled autistic.
4. Extinction of Verbal Behavior
This paradigm is in effect whenever an infant is in an environment
in which parents or other caregivers do not actively prompt, respond
to, and reinforce the child's vocal utterances. Such environments
may occur more frequently than is generally recognized. In today's
culture it is likely that both parents (or the single parent) will
be working and will leave the child in a day-care center or in the
care of a relative, a baby sitter, or a nanny.
Although the staff of
many day-care centers may provide excellent physical care for young
infants and toddlers, the staff may not have sufficient time or
expertise to provide consistent and ongoing reinforcement on a
moment to moment basis for the verbal behavior of each individual
infant. Hart and Risley (1995) stated, "Quality out-of-home
care can be provided for infants and young children, even though
it rarely is" (p.207), moreover, "the most important aspect
to evaluate in child care settings for very young children is the
amount of talk actually going on moment to moment, between children
and their caregivers" (p. xxi).
Extinction of verbal
behavior may also occur at home when an infant is cared for by
relatives, a baby sitter, or a nanny. The research of Hart and
Risley (1995) indicates that the essential element in language
delay appears to be, "How frequently does the caregiver
talk with the child each hour?" If there is little or no talk
between caregiver and infant each hour during the hours of care,
the verbal behavior of the child may be on extinction. In one case,
the parents, both of whom worked long hours, left the child at home
in the care of a non-English speaking nanny. The nanny was specifically
instructed not to speak to the child in her native language. The
child developed no language and was diagnosed with PDD at age 2 years.
It is, of course, impossible to draw a causal relationship without
knowledge of the major verbal and other contingencies that may have
been in effect during the two year period (e. g., How much did the
parents talk to the child when they were at home in the evenings
and weekends? Did the nanny acquire some English and begin to speak
to the child during the two year period?). This case, however, illustrates
how it might be possible for extinction to operate in a seemingly
normal home environment if a high hourly rate of conversation between
caregiver and child does not occur.
Relatively few children who spend time in alternative placements
will be seriously language delayed, and even fewer will be diagnosed
with autism or PDD. However, as Hart and Risley (1995, 1999) have
shown, degree of language delay is relative and is directly related
to the frequency of talk between parent and child that infants and
children receive during the first three years of life.
Other environmental events that may disrupt or reduce the frequency
of reinforcement for verbal behavior or place it on extinction during
the critical first two years of life have been discussed by Fowler
(1990). Some of these include prolonged physical or emotional illness
of one or both parents, death of a parent, moving to a new residence,
increased work demands on the time of one or both parents, and placing
the child with a new caregiver or nanny. Extinction of verbal behavior
might also occur when children are allowed to sleep or remain isolated
in their crib without adult interaction for inordinate amounts of
time each day over an extended period of weeks or months.
5. Interaction Between Organic or Presumed Organic Factors and
Behavioral Factors
Certain physical disabilities such as hearing loss, chronic ear
infections, or prolonged illness, especially when occurring during
the first two years of life, can directly interfere with the establishment
of verbal behavior (Bijou, 1966, 1983). Other physical disabilities
may have no direct effect on a child's ability to produce verbal
behavior. However, it is the reaction of the parents or caregivers
to the disability or presumed disability that may function
to reduce subsequent requirements for verbal behavior due to a fear
of precipitating additional problems. In one case, the parents of
a 2 1/2-year-old child who was later diagnosed with autism, believed
their child had chronic ear infections because he screamed and covered
his ears whenever they spoke to him. They discontinued their efforts
to teach language because they believed it caused him pain. In another
case, the parents of a 3-year-old verbally delayed, asthmatic child
decreased their attempts to teach language for fear of precipitating
an asthmatic attack (Drash & Tudor, 1989).
6. Non-suppression of Disruptive Behavior and Failure to Establish
Early Verbal Instructional Control and Compliance
In contrast to the first five paradigms that detail how reinforcement
contingencies may operate to create specific behavioral repertoires
consistent with a diagnosis of autism, this section describes
the absence of specific caregiver behaviors that may contribute
to the establishment of disruptive behaviors typically observed in
children labeled autistic. From birth to three years of age many
typical children engage in a variety of behaviors designated as disruptive,
oppositional, defiant, or noncompliant (i. e., "the terrible
twos"). During these years most parents attempt to reduce or
eliminate those behaviors and strengthen socially acceptable responses.
In the case of children
diagnosed with autism, the elimination of disruptive and noncompliant
behavior is even more critical. As stated by Charlop-Cristy and
Kelso (1997), "The rationale behind
compliance training is simple - if the child does not comply, then
he will not learn! Compliance plays a vital role in every aspect
of the learning situation" (p. 53).
Parents and caregivers of children labeled as autistic often
demonstrate lack of control over the disruptive and noncompliant
behaviors of their children. Such behaviors may include
screaming, severe temper tantrums, kicking, hitting, biting, throwing
objects, jumping on furniture, damaging property, and running about
uncontrollably. These behaviors are quite functional for the child
in at least two ways. First, they allow the child to obtain reinforcement,
for example, by screaming until he is given a specific toy, food,
or other reinforcer, and second, they allow the child to avoid
or escape compliance with parental or caregiver demands or requests.
Parents often report that they believe these behaviors are an integral
component of their child's disability, and that their child is
unable to control the behavior. Parents often do not provide the
consequences necessary to reduce or eliminate these behaviors,
believing that doing so might cause additional problems. (See also
Paradigm 5 above.)
In some cases the non-confrontive behavior of parents may have
been shaped over a period of months or years by the aversive contingencies
of the child's behavior. After many unsuccessful attempts to reduce
or eliminate disruptive and noncompliant behaviors, parents may simply
discontinue attempting to discipline the child as they might a typical
child. These disruptive and oppositional behaviors become increasingly
more severe and difficult to manage as the child becomes older and
stronger.
In one extreme but illustrative case, a 2-year-old child was referred
for failure to develop language. The parent's main concern, surprisingly,
was not the child's language delay, but rather the child's severe
temper tantrums and aggressive behavior. The mother reported that
she was forced to carry him wherever she went. When she attempted
to put the child down, he screamed and attacked her viciously by
biting, pinching, hitting, and pulling her hair until she picked
him up and cuddled him, thus further reinforcing the aggressive behavior.
The mother was adamant that these behaviors were part of his disability
and could not bring herself to discipline him.
How the Presence of Disruptive and Avoidant Responses and the Lack
of Verbal Behavior May Contribute to Deficiencies in Social-Emotional
Development
During the first two
years of a child's life, parents provide the vast majority of stimulation,
teaching, and reinforcement necessary for children to acquire verbal
behavior, social bonding, and a variety of social skills (Hart & Risley, 1995, 1999). During the first
year, typical infants receive ongoing informal training in social
and pre-language skills from their parents or caregivers on a daily
basis (Bruner, 1983). Parents routinely reinforce a variety of social
and pre-language behaviors including eye-contact, responding to name,
kissing, hugging, babbling, cooing, clapping, singing, smiling, laughing,
looking at books, pointing to pictures and objects, playing interactive
games, and following simple instructions. In so doing a repertoire
of receptive language (i. e., verbal instructional control and compliance)
is being established, and the child's behavior is being brought under
the stimulus control of verbal behavior (i. e., "Show me your
nose, eyes, ears," "Touch the apple," "Give me
the ball," "Where is your bottle, teddy bear?" etc.)
Consequently, by 18 to 24 months the typical toddler has developed
an extensive and relatively complex repertoire of social behaviors,
a relatively large receptive vocabulary, is coming under the stimulus
control of verbal behavior, and is beginning to develop expressive
verbal behavior.
However, if during the critical first 12 to 18 months,
negative manding and disruptive avoidance responses are reinforced
and strengthened, this predominant response repertoire may become
incompatible with the development of interactive parent-child social
behaviors. Consequently when parents attempt to teach
social and pre-language behaviors, pre-established patterns of
aversive manding and disruptive avoidance behavior may function
to decrease the time parents spend teaching their child. This may
ultimately produce large deficits in social-emotional and pre-language
behaviors normally established during the first two years of life,
and the child may begin increasingly to avoid interactions with
adults and other children.
If pervasive extinction, as described in Paradigm 4, is in effect
rather than aversive manding, then, by definition, limited teaching
opportunities will have occurred, and very few age-appropriate social
behaviors will have been established. Extinction may ultimately produce
a child whose behavior is relatively unresponsive to human interaction.
Once deficits in the social-emotional repertoire occur, either
through extinction or avoidance, it becomes increasingly difficult
to engage the child in effective teaching interactions. Parental
time that might ordinarily be spent teaching language and social
behaviors, as well as in establishing novel conditioned reinforcers,
may be directed toward avoiding interactions that occasion disruptive
or avoidance behavior. This is illustrated by the example of the
2-year-old described in Paradigm 6. The child's disruptive behaviors
were so severe that whenever the mother attempted to engage him in
a teaching interaction, he immediately began screaming and pulling
her hair. The mother consequently terminated her attempts to teach
the child.
How Contingencies May Concurrently Shape Restricted, Repetitive,
and Stereotyped Response Repertoires
Children who have not
acquired age-appropriate verbal behavior and social repertoires
by 2 years of age are necessarily restricted to a very limited
set of responses typical of pre-linguistic infants and children.
These are primarily cause-and-effect activities that provide automatically
reinforcing sensory stimulation. Typical behaviors include thumb-sucking,
mouthing and banging objects, finger flicking, hand flapping, spinning
objects, inspecting specific aspects of toys, or rubbing the surface
of objects. As the child grows older many of these behaviors may
come under the control of other environmental contingencies. For
example, an automatically reinforcing behavior such as pressing
one's eye, may be unintentionally reinforced and shaped into a
more serious self-injurious behavior by the attempts of caregivers
to prevent the behavior. In addition to automatic reinforcement,
research has shown that self-injurious, repetitive, and perseverative
behaviors may be reinforced and maintained by positive reinforcement
or by avoiding or escaping aversive contingencies (Durand, 1999;
Iwata, Dorsey, Slifer, Bauman, & Richman, 1994).
Since the development in young children of conditioned social reinforcers,
such as playing ball, tag, or hide and seek, is dependent in large
measure on verbal behavior and verbal instructional control, a lack
of verbal behavior necessarily restricts the child's repertoire to
those repetitive and stereotyped behaviors typically associated with
younger children.
Advantages of Conceptualizing Autism as a Contingency-Shaped Disorder
of Verbal Behavior
Conceptualizing autism as a contingency-shaped disorder of verbal
behavior represents a significant departure from the contemporary
neurobiological theories of its etiology and provides a new paradigm
(Kuhn, 1966) for behavioral research in autism. It is relevant to
ask what changes may result from this conceptualization and whether
these changes may represent a substantial improvement over the current
approaches to prevention, early intervention, and treatment of autism.
A number of the potential changes and concomitant advantages that
might result from this conceptualization are discussed below.
Conceptualizing Autism as a Contingency-Shaped Disorder of Verbal
Behavior Creates a New Paradigm for Behavioral Research and Treatment
in Autism
Since autism has previously
been viewed primarily as a neurobiological disorder, there has
been little incentive for behavioral researchers in the field of
autism to conduct experimental analyses of the contingencies of
reinforcement that exist between parent and child from birth to
one year, especially as those contingencies relate to the shaping
of verbal behavior. Moreover, there have been and continue to be
significant "politically correct" pressures, both from
within and outside the profession, that have strongly mitigated against
conducting research that might implicate contingencies of reinforcement
between parents and children as significant factors in the etiology
of autism. However, when autism is viewed, not as a neurobiological
disability or a disease entity, but as a contingency-shaped disorder
of verbal behavior, identifying the specific contingencies that may
prevent or hinder acquisition of verbal behavior becomes a first
priority for behavioral research with the objective of prevention
and earlier intervention.
There are at least two
lines of research that may be immediately productive in evaluating
the effects of reinforcement contingencies in the shaping of behaviors
that may later result in the diagnosis of autism. Behaviors correlated
with a later diagnosis of autism can be identified at least as
early as 8 to 10 months, and perhaps earlier (Werner, Dawson, Osterling, & Dinno, 2000). Consequently,
behavioral research focusing on specific parent-child reinforcement
contingencies that establish the initial stages of verbal behavior
between birth and 12 months would be particularly useful in showing
how the precursors of verbal behavior are shaped and precisely what
behaviors may be incompatible with or prevent the acquisition of
verbal behavior. Further analysis of the role of automatic reinforcement
as it relates to the shaping of verbal behavior during the first
year would also be quite valuable (Bijou & Baer, 1965; Skinner,
1957; Smith, Michael, & Sundberg, 1996; Sundberg & Michael,
2001; Sundberg, Michael, Partington, & Sundberg, 1996).
A second related line of research would be to investigate the role
of aversive manding and other avoidance behaviors in preventing the
acquisition of verbal behavior. Since avoidance behaviors and aversive
manding are strongly implicated as casual factors in this analysis
of language delay, it would be important to examine the early stages
of language acquisition to evaluate precisely how aversive manding
and disruptive avoidance behaviors are originally established and
how these behaviors may function to prevent acquisition of appropriate
verbal and social behavior. It would also be useful to analyze why
and how avoidance behaviors are shaped in some children and not others.
Preventing Autism
Now: A Practical Behavioral Strategy That Can Be Implemented
Immediately
One of the major goals
of both behavioral and biomedical research in autism during recent
years has been to identify causal variables that might lead to
comprehensive programs for the prevention or cure of autism that
could be implemented immediately [i. e. Cure Autism Now (CAN);
Defeat Autism Now! (DAN!)]. This goal also has been strongly supported
by parent advocacy groups nationwide (Grossman & Beck,
2002; Jacobson, 2000; Maurice, 1996, 2001; Perry, 2001).
This analysis of autism as a contingency-shaped disorder of verbal
behavior provides Behavior Analysts with the unique ability to answer
one of the most long-standing and challenging questions of parents
and parent advocates nationwide, "How can autism be prevented?" Based
on the current analysis, it should be possible to begin to prevent
many cases of autism immediately by identifying reinforcement contingencies
that might prevent or inhibit the development of verbal behavior
during the period between birth and 18 to 24 months and replacing
them with reinforcement contingencies that could establish age-appropriate
verbal and social behavior.
One important component of ABA prevention programs would be to
establish, as soon as feasible, a nation-wide network of Applied
Behavior Analysis screening programs for parents and their infants
between birth and 24 months that would focus on identifying and modifying
contingencies and behaviors that may interfere with acquisition of
age-appropriate verbal behavior. Once these contingencies are identified,
parents could be taught to replace them with contingencies that will
shape age-appropriate verbal and social behavior by age 2 to 3 years.
In those cases in which complete prevention might not occur, prevention
efforts could lead directly into ABA early intervention programs.
For a related discussion of behavioral prevention programs, see Drash
and Tudor (1990, 1993).
Based upon the success
of previous prevention and early intervention programs, there is
a high probability that the more severe symptoms of autism might
never occur (Anderson, Avery, DiPietro, Edwards, & Christian,
1987; Begab, Haywood, & Garber, 1981; Bijou, 1983; Birnbrauer & Leach,
1993; Drash, 1992; Drash & Raver, 1987; Drash, Raver & Murrin,
1987; Fenske, Zalenski, Krantz, & McClannahan, 1985; Garber,
1988; Guralnick, 1997; Harris, Handleman, Gordon, Kristoff, & Fuentes,
1991; Lovaas, 1987; Menolascino & Stark, 1988; Smith, Groen, & Wynn,
2000).
Developing a Contingency-Based Strategy for Earlier Intervention
One of the principle goals of contingency-based early intervention
programs would be to begin ABA intervention programs before the repertoires
of aversive manding and disruptive avoidance behaviors are well established.
As shown by several of the cases presented previously, the disruptive
and avoidance behaviors of children diagnosed with autism / PDD are
often well established by 18 months to two years.
If behavioral interventions that are focused on the development
of appropriate verbal and social behavior and elimination of disruptive
and avoidance behaviors are begun during the first year to 18 months,
the probability for total recovery may be greatly enhanced. Green,
Brennan, and Fein (2002) recently reported on a case in which early
intensive behavioral treatment of a 1-year-old child at high-risk
for autism produced total recovery within a period of three years.
This study demonstrated the effectiveness of ABA intervention for
autism at a younger age than has been previously reported.
Reducing the Number of Treatment Hours per Week and the Total
Length of Treatment
Since the degree of pre-language
or language delay is necessarily small at age 6 to 18 months and
the incompatible avoidance behaviors usually are not well established,
it should be possible to restore young children to "relatively normal functioning" much
more rapidly than older children who have well established repertoires
of disruptive and avoidance behaviors. The Lovaas (1987) program
required two to three years of 40-hours-per- week of intensive individual
ABA treatment to achieve recovery when children began treatment at
an average age of three years. Therefore, if ABA treatment is begun
between 6 and 18 months, it should be possible to restore a child
to relatively normal functioning within one to two years.
Our research with children
diagnosed as autistic, PDD, or at-risk in the age range of 18 months
to 2 1/2 years suggests that, for some children, a program of far
less intensity than a 40-hour-per-week program may be sufficient
to produce substantial recovery within one to two years. In one
previously published case, a 19-month-old seriously language delayed
child, diagnosed as at-risk, achieved relatively normal language
and behavioral functioning after 10 months of in-office ABA verbal
behavior therapy consisting of a total of only 52 one-hour sessions
(1 to 2 sessions per week) (Drash & Tudor,
1989, pp. 30-31; 1990, pp. 199-201). In a second case, a 2 1/2-year-old
nonverbal child, diagnosed with aphasia, achieved relatively normal
language and behavioral functioning after 11 months of in-office
ABA verbal behavior therapy consisting of 36 one-hour sessions (1
to 2 sessions per week) (Drash, 2001).
The total number of therapy hours provided to each of these two
children was only a fraction of that typically provided in a 40-hour-per-week
in-home Applied Behavior Analysis program over a comparable duration.
For the first child the comparison is 52 hours vs. 1600 hours or
3%, and for the second child 36 hours vs. 1760 hours or 2%. At present
these two cases clearly represent the exception rather than the rule.
However, they suggest that, in some cases, both the length
and intensity of treatment for younger children, especially those
considered at-risk, may be considerably less than that required for
older children.
Making "Functional Recovery" a
Routine and Expected Outcome in ABA Treatment of Young Children
with Autism
As a result of recent
advances in the field of Applied Behavior Analysis, relatively
total recovery or cure is now recognized as a legitimate and obtainable
outcome in the behavioral treatment of autism (Maurice, 1993; Maurice,
Green, & Foxx, 2001; Maurice,
Green, & Luce, 1996; McEachin, Smith, & Lovaas, 1993; Lovaas,
1987). At present, however, total recovery as an outcome remains
the exception rather than the rule in the treatment of autism. Moreover,
some career experts in autism continue to maintain that total recovery
is impossible (Mesibov, 1997) and appear unwilling to consider evidence
that indicates children have totally recovered.
The dispute over the
term "total recovery" greatly
detracts from the fact that hundreds of children are daily making
excellent progress in ABA treatment programs, and many are, for all
practical purposes, substantially recovering from autism (Maurice,
2001). To avoid the controversy surrounding the term "total
recovery" we propose the term "functional recovery" that
would operationally define the condition of many children
who have made excellent improvement in language, intelligence, and
social behavior, but who may or may not be described as "totally
recovered." Objective measures might include successful functioning
in regular grade, ability to interact appropriately and independently
in social situations, elimination of temper tantrums and other disruptive
or avoidance behaviors, and normal functioning on standardized tests
of language, intelligence, social adjustment, and academic subjects.
This would allow for the establishment of an objective continuum
of treatment outcomes, ranging from slight or no improvement,
to partial recovery, to functional recovery, to total recovery.
By describing each category in operational terms based on direct,
replicable observations of behavior, much of the controversy regarding
the effects of ABA treatment could be avoided, and the realistic
benefits of ABA treatment could be more easily recognized and accepted.
Conclusion
Conceptualizing autism
as a contingency-shaped disorder of verbal behavior that begins
during the first year of life provides a new paradigm for behavioral
research and treatment in the areas of prevention, earlier intervention,
and recovery from autism. By beginning ABA therapy during the first
6 to 18 months and focusing on modification of the specific contingencies
of reinforcement that may prevent or interfere with acquisition
of verbal behavior, it may be possible to prevent many cases of
autism and reduce the debilitating effects of many others. The
duration and intensity of treatment may be reduced, and "functional recovery" from
autism might become the norm and expected outcome of ABA treatment.
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back to Autism Articles & Chapters
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