The Analysis of Verbal Behavior                                                              2004, 20, 5-23             An...
6                       PHILLIP W. DRASH & ROGER M. TUDORries ofautism describe how environmental con-          and treatm...
THE ETIOLOGY OF AUTISM                                                7Behavioral Theories ofAutism                       ...
8                      PHILLIP W. DRASH & ROGER M. TUDOR  In order to demonstrate that behavioral con-       This category...
THE ETIOLOGY OF AUTISM                                               9dren labeled as autistic. While agreeing with       ...
10                      PHILLIP W. DRASH & ROGER M. TUDORwith and may prevent the acquisition of age-           appear to ...
THE ETIOLOGY OF AUTISM                                              11research reported that 50% of parents ofa child     ...
12                      PHILLIP W. DRASH & ROGER M. TUDOR Skinner, 1957). The first cries of an infant are      paradigm. ...
THE ETIOLOGY OF AUTISM                                                 13duce a variety of vocal sounds. But when         ...
14                      PHILLIP W. DRASH & ROGER M. TUDOR to moment basis for the verbal behavior of each     mands on the...
THE ETIOLOGY OF AUTISM                                             15   In the case of children diagnosed with au-        ...
16                      PHILLIP W. DRASH & ROGER M. TUDORcreasingly to avoid interactions with adults and     maintained b...
THE ETIOLOGY OF AUTISM                                          17tingency-shaped disorder of verbal behavior,       that ...
18                     PHILLIP W. DRASH & ROGER M. TUDORDeveloping a Contingency-based Strategy           child, diagnosed...
THE ETIOLOGY OF AUTISM                                           19 ery" we propose the term "functional recov-           ...
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An analysis of autism as a contingency shaped disorder of verbal behavior-drash and tudor 2004


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An analysis of autism as a contingency shaped disorder of verbal behavior-drash and tudor 2004

  1. 1. The Analysis of Verbal Behavior 2004, 20, 5-23 An Analysis of Autism as a Contingency-Shaped Disorder of Verbal Behavior Philip W. Drash, Autism Early Intervention Center Roger M. Tudor, Westfield State CollegeThis paper analyzes autism as a contingency-shaped disorder of verbal behavior. Contingencies of rein-forcement in effect during the first to third year of a childs life may operate to establish and maintain thosebehaviors 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 analy-sis suggests that reliance on neurobiological variables as causal factors in autism is unnecessary. We presentsix 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 childs lifemay contribute substantially to earlier identification, more effective treatment and, quite possibly, to thedevelopment of Applied Behavior Analysis programs for the prevention of autism that could be imple-mented immediately. Conceptualizing autism as a contingency-shaped disorder of verbal behavior mayprovide a new and potentially more effective paradigm for behavioral research and treatment in autism. Autism is widely regarded as one of the most 1997; Maurice, Green, & Foxx, 2001; Maurice,severe of childhood behavioral disorders Green, & Luce, 1996; Leaf, & McEachin,(Barton-Cohen, Allen, & Gillberg, 1992). The 1999; Lovaas, 1977, 1981; Sundberg, &effects of autism are pervasive and interfere Partington, 1998).with the acquisition of normal behavioral rep- Despite substantial progress in the treatmentertoires across almost every area of human of autism, determining the etiology of thosefunctioning. During the past 30 years, exten- behaviors that may later result in a diagnosissive research has been devoted to the develop- of autism continues to be an unresolved issue.ment and implementation of effective behav- The Advocate reported that statistics recentlyioral treatments and to an analysis of the etiol- released by the Autism Society of Americaogy of autism. Since Lovaas (1987) demon- (2002, p. 6) stated that autism is increasing atstrated that it is possible to achieve relatively a rate of 10 to 17% per year. As a result theretotal recovery in some young children diag- has been a strong advocacy for a substantialnosed with autism by using an intensive 40- increase in research into the causes of autism.hour-per-week behavioral intervention, signifi- Discovering the cause of autism is consideredcant progress has been made in the behavioral by many professionals and autism advocatestreatment of children diagnosed with autism. as essential in the development of more effec-These treatments have for the most part relied tive programs for the prevention and treatmenton a functional analysis of behaviors that are of autism. Lee Grossman, President of the Au-labeled as autistic (Charlop-Christy, & Kelso, tism Society ofAmerica, and Robert Beck, Ex- ecutive Director, recently stated (2002), "Af- ter more than 50 years of study, no causes have Earlier versions of this paper were presented at been identified. There needs to be a geometricthe Association for Behavior Analysis, 25th annual increase in research funding ... to determinemeeting, Chicago, IL, May, 1999, and at the 26th the causes of autism" (p. 7).annual meeting, Washington, DC, May, 2000. The Currently there are at least two major hy-authors express their appreciation to Jack Michael,Dick Malott, Mark Sundberg, and Hank Schlinger potheses regarding the causes of autism, thosefor their valuable recommendations on earlier ver- that are primarily neurobiological and thosesions of this manuscript. Send reprint requests to that are primarily behavioral. The neurobiologi-Philip W. Drash, Ph.D., BCBA, Autism Early Inter- cal hypothesis attributes the cause of autism tovention Center, 2901 W. Busch Blvd., Suite 807, a presumed but as yet unidentified neurobio-Tampa, FL, 33618; e-mail: logical disorder. Conversely, behavioral theo- 5
  2. 2. 6 PHILLIP W. DRASH & ROGER M. TUDORries ofautism describe how environmental con- and treatment ofautism that will, in the future,tingencies operating during the first one to three benefit hundreds, and perhaps thousands, ofyears of a childs life may establish and main- young children and their families.tain those behaviors that later result in the di-agnosis of autism. The Neurobiological View of the Causes of This paper presents a behavioral analysis of Autismthe etiology of those behaviors upon which adiagnosis ofautism is based. Our analysis sug- Many contemporary theories of autism havegests that reinforcement contingencies operat- linked its cause to as yet unidentified neuro-ing during the first to third year of a childs life logical or biological factors. In support of thismay play a substantial role in the development position, Minshew, Sweeney, and Baumanof the behaviors that are subsequently diag- (1997) in the Handbook ofAutism and Perva-nosed as autism. We have previously published sive Developmental Disorders (Cohen &an analysis of contingencies of reinforcement Volkmar, 1997) stated, "Autism is now gener-that may lead to delay in acquisition of verbal ally accepted to be a disorder of brain devel-behavior in typical young preschool children opment and hence of neurological origin"(Drash & Tudor, 1990, 1993). A similar analy- (p.344). Similarly in the same volume Dykenssis may also be applied to the shaping of be- and Volkmar (1997) stated, "Researchers gen-haviors that result in the diagnosis of autism erally agree that autism is the result of some(Drash, High, & Tudor, 1999; Drash & Tudor, neurobiological factor or factors" (p. 388).1999, 2000). These popular assumptions about the causes We recognize that the prevailing opinion of autism have spawned at least three nationalamong many professionals and parents, includ- organizations devoted to discovering medical,ing many behavior analysts, is that a disorder neurological, or biological causes of autism:as severe and debilitating as autism could only Cure Autism Now (CAN); DefeatAutism Now!occur through defective neurological or bio- (DAN!); Autism Research Institute, and thelogical mechanisms. We understand and respect National Alliance for Autism Research.their opinions. Moreover, we do not propose Although neurobiological views of thethat this analysis represents the only possible causes of autism are intuitively appealing,explanation for the occurrence ofbehaviors that medical research has failed to provide conclu-result in the diagnosis of autism. We do not sive evidence for a neurological, biological, orrule out the possibility that, in the future, re- genetic cause for autism. In the introduction tosearchers may discover specific neurological, a special issue of the Journal of Autism andbiological or genetic factors that may contrib- Developmental Disorders devoted to contem-ute directly to the development of behaviors porary research in autism, Alexander, Cowdry,that later result in a diagnosis of autism. How- Hall, and Snow (1996) stated, "No consensusever, a behavioral analysis of the cause of au- regarding causes or potential cures for autismtistic behaviors is in no way dependent upon is assumed. This is a problem that is not yetthe presumption of such factors. solved" (p. 118). Likewise, Bailey, Phillips, and Our goals are identical to those of parent Rutter (1996) stated, "a replicable, neurophysi-advocates and other professionals who call for ological basis for autism has not yet been iden-more effective procedures for prevention, treat- tified" (p. 89). More recently other neurobio-ment, and possible cure of autism that can be logical researchers have reached similar con-implemented immediately. Our operating as- clusions. Lauritsen, Mors, Mortensen, andsumption is that a behavioral analysis of the Ewald (1999) stated, "Infantile autism is a het-contingencies that may shape those behaviors erogeneous disorder of unknown etiology" (p.upon which a diagnosis ofautism is based will 335). Trottier, Srivastava, and Walker (1998)ultimately serve the best interests of children reported, "The etiology of autism is complex,diagnosed with autism and their families. We and in most cases the underlying pathologicbelieve that, in the long term, this analysis of mechanisms are unknown" (p. 103). Thus de-autism as a contingency-shaped disorder of spite the prevalence ofthe neurobiological ex-verbal behavior may contribute materially to planation, it is evident that no conclusive sci-the development of more effective behavioral entific evidence for a neurobiological cause forprograms for prevention, early intervention, autism currently exists.
  3. 3. THE ETIOLOGY OF AUTISM 7Behavioral Theories ofAutism cific and identifiable contingencies of rein- forcement in the early environment ofthe child. Behavior analytic explanations ofthe causes One of the first significant behavioral analy- of autism are numerous and diverse. These in- ses of autism was published by Ferster (1961). clude the behavioral hypothesis of Ferster He presented a detailed analysis ofhow a vari- (1961), the contingency-shaped or behavioral ety of contingencies of reinforcement operat- incompatibility theory of Drash and Tudor ing between parent and child during the early (1993, 1999, 2000), the behavioral mismatch years might establish and strengthen a reper-theory of Lovaas and Smith (1989), the social toire ofbehaviors typical of children diagnosedcommunication theory of Koegel, Valdez- as autistic. He observed that a childs disrup-Menchaca, and Koegel (1994), the stimulus tive behaviors may be maintained by their ef-control theory of Spradlin and Brady (1999), fect on his parents or caregivers because theyand the behavioral interference theory of Bijou function as an aversive stimulus that can beand Ghezzi (1999). These behavioral theories terminated ifthe caregiver supplies a reinforcer.all incorporate the view that the behaviors of Moreover, he also observed that over time suchchildren labeled as autistic can be analyzed in aversive behaviors may be strengthened byterms ofthe concepts and principles ofApplied continued reinforcement and become prepotentBehavior Analysis (ABA), and that these con- over other age-appropriate behaviors. Unfor-cepts and principles can produce effective treat- tunately, Fersters analysis was regarded byment programs for children diagnosed with some as a behavioral version of the discardedautism (Ghezzi, Williams, & Carr, 1999). How- psychogenic theory which ascribed autism toever, these theories differ greatly with regard parental personality traits. The implications ofto the initiating cause ofbehaviors upon which the article for research and treatment, includ-a diagnosis of autism is based. ing extensions to the communicative functions With the exception of the first two theories ofaberrant behavior, therefore, were never fully(Drash & Tudor, 1993, 1999, 2000; Ferster, analyzed. 1961) these behavioral theories attribute the In a review of the Bijou and Ghezzi (1999)initiating cause of autism to a defective neuro- analysis, Hayes (1999) cautioned that attribut-logical or biological process that interferes with ing psychological events to biological causes isthe normal developmental process. Lovaas and unnecessary and is an impediment to the devel-Smith (1989) postulate a mismatch between the opment of effective (behavioral) treatmentsnormal environment and the nervous system since it leaves lingering doubt as to the possi-of the child. The Koegel, Valdez-Menchaca, bility of truly successful psychological interven-and Koegel (1994) theory postulates a defec- tion. Likewise, Schlinger (1995) stated that be-tive neurological process that may result in in- havioral or environmental contingencies thatappropriate socialization and defective lan- might account for a behavioral complex shouldguage development. Spradlin and Brady (1999) be ruled out first before attributing the behav-hypothesized that possible neurological limi- ior to neurological, biological, or genetic causes.tations in children with autism make it moredifficult to establish stimulus control. Bijou and CATEGORIES OF BEHAVIOR THAT REQUIREGhezzi (1999) postulated that young children ANALYSIS IF AUTISM IS TO BE CONCEPTUALIZEDwith autism have "abnormalities in their sen- AS A CONTINGENCY-SHAPED DISORDERsory equipment" that produce a "tendency toescape and avoid tactile and mild auditory The Diagnostic and Statistical Manual ofstimuli" (p. 34). This avoidance behavior then Psychiatric Disorders (DSM IV; Americaninterferes with normal social and language de- Psychiatric Association, 1994) outlines threevelopment. These four theories can be termed specific categories of behavior that are con-reductionistic in that they attribute the initiat- sidered essential for an accurate clinical diag-ing cause of autism to an hypothesized but nosis of autism. Since there is no neurobiologi-unidentified neurobiological process. In con- cal or genetic test for autism, the diagnosis oftrast to these, only Drash and Tudor (1993, autism is based entirely on observed behavior.1999, 2000) and Ferster (1961) rely on a com- Based on our research and that of others wepletely behavioral analysis that attributes the have included a fourth category of behaviorearly development of autistic behaviors to spe- that we consider a central feature of autism.
  4. 4. 8 PHILLIP W. DRASH & ROGER M. TUDOR In order to demonstrate that behavioral con- This category includes behaviors such as ste-tingencies may be largely, if not completely, reotyped body movements, hand flapping, per-responsible for the behavioral complex diag- sistent preoccupation with specific parts ofnosed as autism, it is necessary to analyze how objects, emotional responses to inconsequen-contingencies of reinforcement may establish, tial alterations in trivial aspects of the environ-shape, and maintain the behaviors that com- ment, unreasonable insistence on followingprise each ofthese four categories ofbehavior. specified routines in precise detail, preoccu- pation with specific responses, such as smell-Qualitative Impairment in Communication as ing or spinning objects. The range and varietyManifested by Little or No Spoken Language of environmental stimuli that function as rein- forcers is also markedly restricted. Severe language deficiency is a classic fea- Moderate to Severe Disruptive Behaviors,ture ofautism (Churchill, 1978; Richter, 1978; Task-Avoidance, and NoncomplianceRutter, 1974, 1978). Autism in young childrenis rarely diagnosed in the absence of a signifi- Disruptive behaviors, task-avoidance, andcant deficiency in spoken language. Indeed, it noncompliance are not specified as distinctis the lack ofage-appropriate spoken language diagnostic criteria for autism in the DSM age 2 to 3 years that typically initiates the However, we view these behaviors as both typi-entire referral, diagnostic, and treatment pro- cal and critical components in most cases ofcess. Many children diagnosed with autism at autism. Moreover, in his original papers on2 to 3 years of age have little or no expressive autism, Kanner listed a variety of disruptiveor receptive verbal behavior, while others have behaviors including temper tantrums, aggres-minimal receptive repertoires but no expres- siveness, and destructiveness as characteristicsive verbal behavior. Many 2 and 3-year-old of children with autism (Frith, 1991). There ischildren when first diagnosed with autism are also overwhelming evidence in the researchfunctioning at a 9 to 12 month level of lan- literature on autism that documents that chal-guage acquisition. Thus, serious deficiency in lenging behaviors are highly typical of chil-or lack ofspoken language repertoires may be dren labeled as autistic (Carr & Durand, 1985,the primary and essential distinguishing char- 1986; Charlop-Christy & Kelso, 1997; Durand,acteristic of autism, since without deficiency 1999; Iwata, Dorsey, Slifer, Bauman, &in spoken language such children quite prob- Richman, 1994; Leaf & McEachin, 1999;ably would not be diagnosed as autistic. Lovaas, 1993; Repp, & Singh, 1990). Typical behaviors in this category include crying,Qualitative Impairment in Social Interaction screaming, temper tantrums, head-banging,Including Marked Social Isolation and kicking, biting, task-avoidance, non-respon-Impairment in Peer Relationships siveness, noncompliance, aggressive behavior, self-stimulatory behavior, and self-injurious behavior. Social isolation and delay in age-appropri-ate social behavior is a second major category How CONTINGENCIES OF REINFORCEMENTof behavior typical of children with autism. MAY OPERATE TO ESTABLISH AND SHAPE THEAlmost all children diagnosed with autism have BEHAVIORS THAT SUBSEQUENTLY RESULT IN Asome deficits or impairment in their social rep- DIAGNOSIS OF AUTISMertoires. Behaviors in this category includesocial isolation and aloneness, avoidance of In summarizing their interference theory ofeye-contact, lack of age-appropriate social play, autism, Bijou and Ghezzi (1999) concluded,lack of responsiveness to other persons, and "... most ofthe abnormal behaviors of childrenlack of age-appropriate social-interactional with autism serve to compensate for their defi-skills. ciencies in social-emotional and verbal behav- ior" (pp. 39-40). Based on their analysis, defi-Markedly Restricted, Repetitive, and Stereo- ciencies in social-emotional behavior and ver-typed Patterns ofBehavior, and Limited bal behavior are alone sufficient to account forResponsiveness to Environmental Stimuli most ofthe behaviors that are observed in chil-
  5. 5. THE ETIOLOGY OF AUTISM 9dren labeled as autistic. While agreeing with neurological, biological, or genetic abnormali-much of their analysis, we differ substantially ties is not disputed. This would not be incom-in at least three respects. patible with our contingency-shaped theory. First, we view autism primarily as a contin- Since the diagnosis of autism is based entirelygency-shaped disorder of verbal behavior that on a continuum of observed behaviors, i.e.,often coexists with a repertoire of avoidance "autism spectrum disorders" (Wetherby &and other disruptive behaviors. In order to ana- Prizant, 2000), the diagnosis will, on occasion,lyze the causes of autism, it is first necessary almost inevitably include subsets of atypicalto analyze the causes of deficiency in verbal children, who in addition to their principal dis-behavior. As will be discussed below, the so- order, such as Down syndrome, Fragile X syn-cial-emotional deficits of children with autism drome, or Retts disorder, may also displaycan be causally linked by a behavioral analy- behaviors that are typical ofchildren diagnosedsis to the deficiencies in verbal behavior and as autistic. In other cases, children diagnosedthe presence of disruptive avoidance behaviors. with autism may later be found to have sei- Second, we view the presence of inappro- zures, brain tumors, or other physiologicalpriate verbal behavior, that is, aversive vocal problems which may have contributed to themanding (e.g., screaming, crying or whining) development of autistic combination with avoidance and other dis-ruptive behaviors, rather than age-appropriate BASIC PREMISES OF A BEHAVIORAL ANALYSISverbal behavior (such as, pre-speech vocal OF AUTISM AS A CONTINGENCY-SHAPEDsounds, words, phrases, etc.) as primary causal DISORDER OF VERBAL BEHAVIORfactors contributing to the shaping and main-tenance of other behaviors on which a diagno- To analyze autism as a contingency-shapedsis of autism is based. Both experimental and disorder of verbal behavior it is necessary toclinical evidence details how repertoires of provide a conceptual analysis showing howaversive vocal manding and other disruptive reinforcement contingencies may establish andavoidance behaviors can be shaped by rein- maintain a repertoire ofdeficient verbal behav-forcement contingencies, and once established, ior and disruptive avoidance behaviors duringare incompatible with the acquisition of func- the first one to two years of life.tional verbal behavior (Drash, 1993; Drash, The purpose of this paper is to present a con-High, & Tudor, 1999; Drash & Tudor, 1993, ceptual analysis that extends well establishedRichter, 1978). Moreover, since many ofthese behavioral principles to an analysis of the eti-more aversive behaviors terminate parent-child ology of behaviors that are later diagnosed asinteractions, they may also prevent or inhibit autistic. All of the terms of this analysis referthe establishment of social-emotional bonding to potentially modifiable conditions in theand other social behaviors. These two reper- childs environment and directly observabletoires, aversive vocal manding and other dis- and measurable aspects of his performance.ruptive behaviors, may thus be responsible for Moreover, experimental evidence supportsmost of the other behavioral symptoms of au- each of the basic premises of this analysis.tism. There are at least four major premises upon Third, absence of age-appropriate verbal which this analysis is based. In summary, thesebehavior and the presence ofavoidance behav- are: 1) The acquisition of verbal behavior, orior can be explained as a result of contingen- the lack thereof, by children labeled as autisticcies of reinforcement operating during the first is primarily a function of reinforcement con-to third year of a childs life, especially during tingencies provided by caregivers and othersthe first 12 to 18 months. A behavioral analy- during the first years of a childs life. 2)sis of those contingencies explains the devel- Caregivers and others may inadvertently shapeopment or lack of development of verbal be- repertoires of disruptive and avoidance behav-havior and the presence of disruptive and iors in their infants and young children duringavoidance behavior without relying on hypo- the first one to three years of a childs life. 3)thetical neurological variables to explain their Disruptive and task-avoidance responses areoccurrence. frequently present in young children diagnosed The fact that there may be subsets of chil- with autism, or PDD. 4) When present, dis-dren diagnosed as autistic with accompanying ruptive behaviors may become incompatible
  6. 6. 10 PHILLIP W. DRASH & ROGER M. TUDORwith and may prevent the acquisition of age- appear to be operants under the control ofappropriate verbal behavior, as well as other occasioning stimuli and consequences inadvert-social behaviors. ently provided ... by the responding of well-in- The first question is whether and to what tentioned, loving parents" (1999, p. 272). Thus,degree contingencies of reinforcement pro- without intending to do so, parents may shapevided by caregivers and others may facilitate disruptive behaviors during the first year of lifeor impede the language acquisition of their which may interfere with the acquisition of morechildren. Empirical support for the concept that adaptive responses.parents strongly influence the language acqui- The third question is whether disruptive andsition oftheir children from infancy forward is task-avoidance responses are frequentlyprovided by the longitudinal research of Hart present in young children diagnosed with au-and Risley (1995, 1999) on language develop- tism or PDD. We have previously shown thatment in children from 7 months to 3 years. aversive manding and other disruptive avoid-Their research shows that the frequency and ance behaviors are frequently present in youngcomplexity, or lack thereof, of the childs ver- children diagnosed with autism or PDD. Anbal behavior at age 3 years is directly related analysis of all cases (N = 48) admitted duringto the frequency and complexity of verbal be- 1992 and 1993 with a diagnosis of autism orhavior that occurs between parents and their PDD, revealed that in 41 of the 48 cases, or inchildren from the first year of life forward. 85% ofthe cases, disruptive or task-avoidanceWhen the hourly frequency of talk between behavior was present and was a major factorparent and child was high, the children devel- interfering with acquisition of verbal behavioroped large vocabularies and spoke in complex (Drash, 1993).sentences by age three. When the hourly fre- The final question is whether it is possiblequency of talk between parent and child was for aversive manding and other disruptive be-low, children developed much smaller vocabu- haviors, when present, to prevent the acquisi-laries and spoke in much less complex sen- tion of verbal behavior. We have shown thattences. This finding suggests that if there is very aversive manding and other avoidance behav-little or no interactive talk between parent and iors when present may be incompatible withchild during the first year to three years, the the acquisition of age-appropriate verbal be-childs verbal behavior may be deficient at three havior. It is only after inappropriate verbal be-years. havior and other disruptive behaviors are In keeping with our premise that acquisition greatly reduced or eliminated by providing re-of verbal behavior is a function of contingen- inforcement only for acceptable vocal mandscies of reinforcement, Hart and Risley (1999) (that is, extinction combined with differentialconcluded, "We propose that language devel- reinforcement of acceptable vocal mands), thatopment is governed by the same natural laws shaping of appropriate vocal mands can pro-as motor, social, and cognitive development" ceed. (Drash, High, & Tudor, 1999).(p. 199). The contingency-shaped theory of autism is The second question is whether caregivers based entirely on behaviors that are readilyand others, during the first year of a childs observable, measurable, and modifiable, andlife, may unintentionally shape disruptive in- the analysis is thus subject to further experi-fant response repertoires. In a series of experi- mental analysis and verification.mental studies ofemotional behavior of infants,ages 6 to 12 months, and their parents, Gewirtz WHEN Do CONTINGENCIES OF REINFORCEMENTand Pelaez-Nogueras (1991, 1999) demon- BEGIN TO SHAPE THE BEHAVIORS THAT AREstrated that disruptive infant behaviors, such LATER DIAGNOSED AS AUTISTIC?as crying, whining, and screaming, can be in-advertently shaped by parents during the first Until recently the diagnosis of autism wasyear of life. Moreover, the parent-infant con- rarely made before a child was 2 to 3 years oftingencies that shape the disruptive behaviors can age. Despite this, accumulating evidence sug-be identified and modified as early as 6 to 9 gests that many parents have expressed con-months of age. In discussing how disruptive in- cern to their pediatrician about their childs lan-fant behaviors may be shaped, they concluded, guage and social delay by 18 months of age"The infant adaptive problem behaviors actually (Siegal, Pliner, Eschler, & Elliot, 1988). Other
  7. 7. THE ETIOLOGY OF AUTISM 11research reported that 50% of parents ofa child behavior in children diagnosed as autistic isdiagnosed as autistic suspected a problem be- provided by Sundberg and Michael (2001) andfore their child was 1 year old (Ornitz, Guthrie, Sundberg and Partington (1998).& Farley, 1977). Barton-Cohen, Allen, andGillberg (1992) demonstrated that behaviors REINFORCEMENT PARADIGMS THAT MAYthat are correlated with a later diagnosis of CONTRIBUTE TO THE DEVELOPMENT OFautism can be accurately identified at 18 DEFICIENT VERBAL REPERTOIRES INmonths. More recent research has shown that CHILDREN WITH AUTISMbehavioral correlates of a later diagnosis ofautism can be identified as early as 8 months In a previous publication we presented an(Werner, Dawson, Osterling, & Dinno, 2000) analysis of reinforcement contingencies thatto 12 months (Osterling & Dawson, 1994). may contribute to language delay in young pre- The fact that behaviors correlated with a later school children (Drash & Tudor, 1990, 1993).diagnosis of autism can be detected as early as Our research has demonstrated that a similar8 to 12 months, in combination with parental analysis applies equally well to language de-awareness and concern over developmental lay in young children with autism (Drash, High,problems before a child is 12 months old, sug- & Tudor, 1999; Drash & Tudor, 1999, 2000).gests that the contingencies producing lan- There are at least six reinforcement para-guage and social delays are in all likelihood digms that may contribute to significant defi-operating during the first year of life, and quite ciency in verbal behavior that we have identi-possibly as early as 6 to 8 months, if not ear- fied and analyzed in our verbal behavior re-lier. Therefore, a behavioral analysis should search with children labeled as autistic over thefocus on pinpointing those caregiver-infant past thirty years. The observations upon whichinteractions that may establish and reinforce these analyses are based represent multiple rep-aversive vocal mands and other disruptive and lications of within-subject studies in which theavoidance behaviors that occur during the first contingencies preventing acquisition ofverbalyear of life and that may later result in a diag- behavior were repeatedly identified and ana-nosis of autism. The contingencies and result- lyzed, and then systematically replaced withing behaviors, to be described below, in all like- contingencies that produced age-appropriatelihood, have their origins during the first year verbal behavior. Our standard data collectionand are then further shaped, refined, and system for continuous recording and analysisstrengthened as the child develops. of verbal behavior during the shaping of ver- bal behavior has been previously described THE RELATIONSHIP BETWEEN MANDING (Drash & Tudor, 1991). This data recording AND VERBAL DELAY IN YOUNG CHILDREN system allowed us to meet the requirements for LABELED AS AUTISTIC drawing valid inferences from within-subject case studies, replicated across multiple sub- Skinners (1957) analysis of verbal behav- jects, as discussed by Kazdin (1982).ior is particularly relevant to analyzing verbal Each of these six reinforcement paradigmsdeficiency in young children labeled as autis- may contribute to the establishment of a reper-tic. Skinners analysis indicates that verbal toire of behavior that is incompatible with thebehavior is acquired primarily because it pro- acquisition of age-appropriate verbal behavior.duces reinforcement through the mediation of Several of these paradigms may concurrentlyother persons. Skinners (1957) identification create a repertoire of avoidance responses.of the mand as the first verbal operant to beacquired is particularly critical to our analysis. 1. ReinforcementforAversive VocalIf during the first year to three years of life an Manding, such as Crying or Screaming, orinfant is given all the essential, life sustaining Other Avoidance Behaviors that May Bereinforcement and nurture without a require- Incompatible with Acquiring Age-Appropri-ment for age-appropriate vocal manding, then ate Verbal Behaviorit is quite possible that verbal behavior maynot develop. A detailed description of how Manding is the first type of verbal behaviorSkinners analysis of verbal behavior can be emitted by infants (Drash, High, & Tudor,applied to the analysis and treatment of verbal 1999; Drash & Tudor, 1993; Schlinger, 1995;
  8. 8. 12 PHILLIP W. DRASH & ROGER M. TUDOR Skinner, 1957). The first cries of an infant are paradigm. An analysis of all cases (N = 48) respondent in nature and gradually come un- admitted for treatment with a diagnosis of au- der operant control as vocal mands when a tism or PDD during 1992-1993 revealed that caregiver responds to these cries. In most in- 85% had disruptive or task-avoidance behav- stances, the infants cries and screams are trans- ior that interfered with acquisition of age-ap- formed into more acceptable verbal behavior propriate verbal behavior (Drash, 1993). Typi- through the parents subtle shaping and a vari- cal of children in this category is a 3 1/2-year- ety of prohibitions against screaming, crying old child referred for treatment because of se- or fussing (Bruner, 1983; Hart & Risley, 1995; vere language delay. The initial evaluation Schlinger, 1999). Conversely, if caregivers in- showed that the child produced no words or advertently provide reinforcement for crying, other age-appropriate verbal behavior, and he fussing, or screaming to the exclusion of re- emitted severe oppositional behavior. During quiring age-appropriate vocal mands, a strong the initial evaluation he screamed loudly when repertoire of aversive vocal manding may be prompted to produce a word or sound. Twenty- established (Ferster, 1961). For example, if the seven percent of his initial responses were ei-parent has heard the infant produce the sound, ther screams or task-refusals. The mother re- "bababa" on multiple occasions, the parent may ported that at home whenever she promptedprompt the child to say "baba" for bottle by the child to produce a word or sound, the childpresenting the bottle with the verbal prompt, screamed until she ceased prompting him for"Say, bababa." However, if the child has been vocal behavior.without food for some time, the response might A second child, who was first diagnosed asbe a cry or scream, the response that in the past at-risk for autism at 15 months of age, engagedhas been reinforced. To escape the aversive in similar behaviors. When evaluated by us atcrying of the infant, the parent may quickly 3 years of age, he had no expressive verbalpresent the bottle without first requiring an behavior, and his mother reported that he onlyechoic response to the prompt. The infants communicated by screaming. Fifty percent oflikelihood of crying in response to future his baseline responses were either screams orprompts for vocal behavior will have been fur- task-refusals. Temper tantrums were his pre-ther strengthened. Over a longer period of time dominant response when he did not immedi-the caregiver may completely avoid the aver- ately obtain a reinforcer. During the initial in-sive cries of the infant by providing food, milk, terview he began violently kicking his mother.and other reinforcers without first requiring ap- She reported that his tantrums often consistedpropriate vocal responses. The aversive vocal of pinching, kicking, scratching, biting, andmanding of the child can interfere with and head-butting. A speech therapist who beganultimately terminate the parents language therapy with the child at 18 months discontin-teaching efforts and thereby prevent the acqui- ued structured therapy as a result of these dis-sition of age-appropriate verbal behavior. ruptive behaviors. After the contingencies have shaped a strong As demonstrated by both cases, a single vo-repertoire of aversive vocal manding, stimu- calization, the aversive vocal mand, a cry orlus control over these responses will be present. scream, functioned as a generic, all-purposeThe child will show an increased tendency to mandthat the child emitted to obtain reinforce-emit aversive vocal mands and other avoidance ment or to escape or avoid aversive stimuli.behaviors in situations similar to those that The aversiveness of the childs behavior dis-were previously reinforced. For example, the couraged parental attempts to teach more ap-child might pull the parent to the refrigerator propriate verbal behavior.and wait to be given juice or milk. If the parent There are other vocal behaviors that, whileattempts to require that the child first say not as aversive, are functionally equivalent to"juice" or "milk," the child may cry or scream aversive manding in that they are incompat-until given the juice. The teaching efforts are ible with and prevent the acquisition of age-thus terminated, and aversive manding is fur- appropriate vocal behaviors. In one instance, ather strengthened. 2 1/2-year-old child with a diagnosis of apha- The majority of young children in our re- sia was referred for the treatment of languagesearch and clinical programs have had behav- delay. Although the child had no age-appro-ioral repertoires that reflect the influence ofthis priate expressive verbal behavior, he could pro-
  9. 9. THE ETIOLOGY OF AUTISM 13duce a variety of vocal sounds. But when repertoire. This nonvocal repertoire becomesprompted to produce an echoic response, he the childs primary mode of obtaining rein-primarily emitted one sound, "eee." The par- forcement, thereby preventing the acquisitionents were originally amused by this response of age-appropriate verbal behavior.and inadvertently reinforced it, but they soonrealized that the child vocalized few other 3. Anticipating the Childs Needs and Thussounds. The predominance ofthe single sound Reinforcing a Repertoire ofNonresponding"eee" prevented the parents from teaching the that Prevents both Vocal and Nonvocalchild age-appropriate vocal behavior. It was Mandsonly after this single sound was replaced withother more appropriate vocal mands through Although similar in some respects to para-verbal behavior therapy that the child began to digm number two, a significant difference ex-acquire age-appropriate verbal behavior. ists. In this paradigm, caregivers anticipate the After a repertoire of aversive or competing childs "needs and wants" and deliver rein-vocal mands is established, it can be extremely forcement noncontingently before the childresistant to modification. In each of the above mands either vocally or gesturally. This para-cases, a repertoire of aversive manding or other digm may over time establish a repertoire ofincompatible vocal behaviors effectively pre- very low rate behavior in which the child sim-vented acquisition of a repertoire of age-ap- ply waits passively for reinforcement withoutpropriate vocal mands. In addition, these aver- any form of manding, either vocal or gestural.sive behaviors may also prevent or inhibit the Therapeutic attempts to prompt vocal behav-establishment ofsocial-emotional bonding and ior often produce temper tantrums or otherother social behaviors. For a further discussion forms of task-avoidance.of this reinforcement paradigm see Malott, Several parents reported that they anticipatedMalott and Trojan (2000, pp. 295-298). their childs needs to prevent their child from becoming "frustrated." For example, the par-2. Reinforcementfor Gestural Manding and ents of a 2 1/2-year-old nonverbal child re-Other Nonvocal Forms ofManding ported that they anticipated all their childs needs and never required him to speak. They This category includes behaviors such as were unaware that by providing noncontingentlooking at, reaching toward, pointing to, stand- reinforcement they were strengthening a rep-ing next to, or pulling the caregiver toward the ertoire of nonresponding.desired item. During our standard clinical in- Over time this paradigm may produce a si-terview we routinely ask parents of children lent or passive child who "appears to have littlelabeled as autistic the following question, or no interest in the environment," a character-"Since your child cannot talk, how do you istic typical of many children labeled autistic.know what he or she needs or wants?" The mostfrequent response is that their child looks at, 4. Extinction of Verbal Behaviorreaches toward, or pulls them to the desiredobject. Caregivers routinely reinforce and This paradigm is in effect whenever an in-strengthen a repertoire of nonvocal gestural fant is in an environment in which parents ormanding by supplying reinforcing stimuli with- other caregivers do not actively prompt, re-out first setting a contingency for acceptable spond to, and reinforce the childs vocal utter-vocal mands (Drash, High, & Tudor, 1999). If ances. Such environments may occur more fre-the reinforcing stimulus item is not immedi- quently than is generally recognized. In todaysately forthcoming, the child may respond with culture it is likely that both parents (or the singlecrying or screaming until the parent presents parent) will be working and will leave the childthe reinforcer. If the parents believe that their in a day-care center or in the care of a relative,child is unable to speak, they may immediately a baby sitter, or a nanny.provide a reinforcer, thus combining the effects Although the staff of many day-care centersof paradigms one and two. If nonvocal ges- may provide excellent physical care for youngtural manding continues to be reinforced until infants and toddlers, the staff may not havea child is three to four years, it will become sufficient time or expertise to provide consis-deeply ingrained and pervasive in the childs tent and ongoing reinforcement on a moment
  10. 10. 14 PHILLIP W. DRASH & ROGER M. TUDOR to moment basis for the verbal behavior of each mands on the time of one or both parents, and individual infant. Hart and Risley (1995) stated, placing the child with a new caregiver or nanny. "Quality out-of-home care can be provided for Extinction of verbal behavior might also oc- infants and young children, even though it cur when children are allowed to sleep or re-rarely is" (p. 207), moreover, "the most impor- main isolated in their crib without adult inter-tant aspect to evaluate in child care settings for action for inordinate amounts oftime each dayvery young children is the amount of talk ac- over an extended period of weeks or months.tually going on moment to moment, betweenchildren and their caregivers" (p. xxi). 5. Interaction between Organic or Presumed Extinction of verbal behavior may also occur Organic Factors and Behavioral Factorsat home when an infant is cared for by relatives,a baby sitter, or a nanny. The research of Hart Certain physical disabilities such as hearingand Risley (1995) indicates that the essential el- loss, chronic ear infections, or prolonged ill-ement in language delay appears to be, "How ness, especially when occurring during the firstfrequently does the caregiver talk with the child two years of life, can directly interfere with theeach hour?" If there is little or no talk between establishment of verbal behavior (Bijou, 1966,caregiver and infant each hour during the hours 1983). Other physical disabilities may have noof care, the verbal behavior of the child may be direct effect on a childs ability to produce ver-on extinction. In one case, the parents, both of bal behavior. However, it is the reaction of thewhom worked long hours, left the child at home parents or caregivers to the disability or pre-in the care of a non-English speaking nanny. The sumed disability that may function to reducenanny was specifically instructed not to speak to subsequent requirements for verbal behaviorthe child in her native language. The child de- due to a fear of precipitating additional prob-veloped no language and was diagnosed with lems. In one case, the parents of a 2 1/2-year-PDD at age 2 years. It is, of course, impossible old child who was later diagnosed with autism,to draw a causal relationship without knowledge believed their child had chronic ear infectionsof the major verbal and other contingencies that because he screamed and covered his earsmay have been in effect during the two-year pe- whenever they spoke to him. They discontin-riod (e.g., How much did the parents talk to the ued their efforts to teach language because theychild when they were at home in the evenings believed it caused him pain. In another case,and weekends? Did the nanny acquire some En- the parents of a 3-year-old verbally delayed,glish and begin to speak to the child during the asthmatic child decreased their attempts totwo year period?) This case, however, illustrates teach language for fear of precipitating an asth-how it might be possible for extinction to oper- matic attack (Drash & Tudor, 1989).ate in a seemingly normal home environment ifa high hourly rate of conversation between 6. Non-Suppression of Disruptive Behaviorcaregiver and child does not occur. and Failure to Establish Early Verbal Relatively few children who spend time in Instructional Control and Compliancealternative placements will be seriously lan-guage delayed, and even fewer will be diag- In contrast to the first five paradigms thatnosed with autism or PDD. However, as Hart detail how reinforcement contingencies mayand Risley (1995, 1999) have shown, degree operate to create specific behavioral repertoiresof language delay is relative and is directly re- consistent with a diagnosis of autism, this sec-lated to the frequency of talk between parent tion describes the absence ofspecific caregiverand child that infants and children receive dur- behaviors that may contribute to the establish-ing the first three years of life. ment of disruptive behaviors typically observed Other environmental events that may disrupt in children labeled autistic. From birth to threeor reduce the frequency of reinforcement for years of age many typical children engage in averbal behavior or place it on extinction dur- variety of behaviors designated as disruptive,ing the critical first two years of life have been oppositional, defiant, or noncompliant (i.e.,discussed by Fowler (1990). Some of these "the terrible twos"). During these years mostinclude prolonged physical or emotional illness parents attempt to reduce or eliminate thoseof one or both parents, death of a parent, mov- behaviors and strengthen socially acceptableing to a new residence, increased work de- responses.
  11. 11. THE ETIOLOGY OF AUTISM 15 In the case of children diagnosed with au- mother was adamant that these behaviors weretism, the elimination of disruptive and part of his disability and could not bring her-noncompliant behavior is even more critical. self to discipline him.As stated by Charlop-Cristy and Kelso (1997),"The rationale behind compliance training is How THE PRESENCE OF DISRUPTIVE ANDsimple-if the child does not comply, then he AVOIDANT RESPONSES AND THE LACK OF VERBALwill not learn! Compliance plays a vital role in BEHAVIOR MAY CONTRIBUTE TO DEFICIENCIES INevery aspect of the learning situation" (p. 53). SOCIAL-EMOTIONAL DEVELOPMENT Parents and caregivers of children labeledas autistic often demonstrate lack of control During the first two years of a childs life,over the disruptive and noncompliant behav- parents provide the vast majority of stimula-iors of their children. Such behaviors may in- tion, teaching, and reinforcement necessary forclude screaming, severe temper tantrums, kick- children to acquire verbal behavior, socialing, hitting, biting, throwing objects, jumping bonding, and a variety of social skills (Hart &on furniture, damaging property, and running Risley, 1995, 1999). During the first year, typi-about uncontrollably. These behaviors are quite cal infants receive ongoing informal trainingfunctional for the child in at least two ways. in social and pre-language skills from theirFirst, they allow the child to obtain reinforce- parents or caregivers on a daily basis (Bruner,ment, for example, by screaming until he is 1983). Parents routinely reinforce a variety ofgiven a specific toy, food, or other reinforcer, social and pre-language behaviors includingand second, they allow the child to avoid or eye-contact, responding to name, kissing, hug-escape compliance with parental or caregiver ging, babbling, cooing, clapping, singing, smil-demands or requests. Parents often report that ing, laughing, looking at books, pointing tothey believe these behaviors are an integral pictures and objects, playing interactive games,component of their childs disability, and that and following simple instructions. In so doingtheir child is unable to control the behavior. a repertoire of receptive language (i.e., verbalParents often do not provide the consequences instructional control and compliance) is beingnecessary to reduce or eliminate these behav- established, and the childs behavior is beingiors, believing that doing so might cause addi- brought under the stimulus control of verbaltional problems. (See also Paradigm 5 above.) behavior (i.e., "Show me your nose, eyes, ears," In some cases the non-confrontive behavior "Touch the apple," "Give me the ball," "Whereof parents may have been shaped over a pe- is your bottle, teddy bear?" etc.) Consequently,riod ofmonths or years by the aversive contin- by 18 to 24 months the typical toddler has de-gencies of the childs behavior. After many veloped an extensive and relatively complexunsuccessful attempts to reduce or eliminate repertoire ofsocial behaviors, a relatively largedisruptive and noncompliant behaviors, parents receptive vocabulary, is coming under themay simply discontinue attempting to disci- stimulus control of verbal behavior, and is be-pline the child as they might a typical child. ginning to develop expressive verbal behav-These disruptive and oppositional behaviors ior.become increasingly more severe and difficult However, if during the critical first 12 to 18to manage as the child becomes older and stron- months, negative manding and disruptiveger. avoidance responses are reinforced and In one extreme but illustrative case, a 2-year- strengthened, this predominant response rep-old child was referred for failure to develop ertoire may become incompatible with the de-language. The parents main concern, surpris- velopment of interactive parent-child socialingly, was not the childs language delay, but behaviors. Consequently when parents attemptrather the childs severe temper tantrums and to teach social and pre-language behaviors, pre-aggressive behavior. The mother reported that established patterns of aversive manding andshe was forced to carry him wherever she went. disruptive avoidance behavior may function toWhen she attempted to put the child down, he decrease the time parents spend teaching theirscreamed and attacked her viciously by biting, child. This may ultimately produce large defi-pinching, hitting, and pulling her hair until she cits in social-emotional and pre-language be-picked him up and cuddled him, thus further haviors normally established during the firstreinforcing the aggressive behavior. The two years of life, and the child may begin in-
  12. 12. 16 PHILLIP W. DRASH & ROGER M. TUDORcreasingly to avoid interactions with adults and maintained by positive reinforcement or byother children. avoiding or escaping aversive contingencies Ifpervasive extinction, as described in Para- (Durand, 1999; Iwata, Dorsey, Slifer, Bauman,digm 4, is in effect rather than aversive & Richman, 1994).manding, then, by definition, limited teaching Since the development in young children ofopportunities will have occurred, and very few conditioned social reinforcers, such as playingage-appropriate social behaviors will have been ball, tag, or hide and seek, is dependent in largeestablished. Extinction may ultimately produce measure on verbal behavior and verbal instruc-a child whose behavior is relatively unrespon- tional control, a lack ofverbal behavior neces-sive to human interaction. sarily restricts the childs repertoire to those Once deficits in the social-emotional reper- repetitive and stereotyped behaviors typicallytoire occur, either through extinction or avoid- associated with younger children.ance, it becomes increasingly difficult to en-gage the child in effective teaching interactions. ADVANTAGES OF CONCEPTUALIZING AUTISMParental time that might ordinarily be spent AS A CONTINGENCY-SHAPED DISORDERteaching language and social behaviors, as well OF VERBAL BEHAVIORas in establishing novel conditioned reinforc-ers, may be directed toward avoiding interac- Conceptualizing autism as a contingency-tions that occasion disruptive or avoidance shaped disorder of verbal behavior representsbehavior. This is illustrated by the example of a significant departure from the contemporarythe 2-year-old described in Paradigm 6. The neurobiological theories of its etiology andchilds disruptive behaviors were so severe that provides a new paradigm (Kuhn, 1966) forwhenever the mother attempted to engage him behavioral research in autism. It is relevant toin a teaching interaction, he immediately be- ask what changes may result from thisgan screaming and pulling her hair. The mother conceptualization and whether these changesconsequently terminated her attempts to teach may represent a substantial improvement overthe child. the current approaches to prevention, early in- tervention, and treatment of autism. A number How CONTINGENCIES MAY CONCURRENTLY of the potential changes and concomitant ad- SHAPE RESTRICTED, REPETITIVE, AND vantages that might result from this STEREOTYPED RESPONSE REPERTOIRES conceptualization are discussed below. Children who have not acquired age-appro- Conceptualizing Autism as a Contingency-priate verbal behavior and social repertoires by Shaped Disorder of Verbal Behavior Creates2 years of age are necessarily restricted to a a New Paradigm for Behavioral Researchvery limited set of responses typical of pre-lin- and Treatment in Autismguistic infants and children. These are prima-rily cause-and-effect activities that provide Since autism has previously been viewed pri-automatically reinforcing sensory stimulation. marily as a neurobiological disorder, there hasTypical behaviors include thumb-sucking, been little incentive for behavioral researchersmouthing and banging objects, finger flicking, in the field of autism to conduct experimentalhand flapping, spinning objects, inspecting analyses of the contingencies of reinforcementspecific aspects of toys, or rubbing the surface that exist between parent and child from birthof objects. As the child grows older many of to one year, especially as those contingenciesthese behaviors may come under the control relate to the shaping of verbal behavior. More-of other environmental contingencies. For ex- over, there have been and continue to be sig-ample, an automatically reinforcing behavior nificant "politically correct" pressures, bothsuch as pressing ones eye, may be uninten- from within and outside the profession, that havetionally reinforced and shaped into a more se- strongly mitigated against conducting researchrious self-injurious behavior by the attempts that might implicate contingencies of reinforce-of caregivers to prevent the behavior. In addi- ment between parents and children as signifi-tion to automatic reinforcement, research has cant factors in the etiology ofautism. However,shown that self-injurious, repetitive, and when autism is viewed, not as a neurobiologi-perseverative behaviors may be reinforced and cal disability or a disease entity, but as a con-
  13. 13. THE ETIOLOGY OF AUTISM 17tingency-shaped disorder of verbal behavior, that might lead to comprehensive programs for identifying the specific contingencies that may the prevention or cure of autism that could beprevent or hinder acquisition of verbal behav- implemented immediately (i.e. Cure Autism ior becomes a first priority for behavioral re- Now [CAN]; Defeat Autism Now! [DAN!]).search with the objective of prevention and ear- This goal also has been strongly supported bylier intervention. parent advocacy groups nationwide (Grossman There are at least two lines of research that & Beck, 2002; Jacobson, 2000; Maurice, 1996,may be immediately productive in evaluating 2001; Perry, 2001).the effects of reinforcement contingencies in This analysis of autism as a contingency-the shaping of behaviors that may later result shaped disorder of verbal behavior providesin the diagnosis of autism. Behaviors correlated Behavior Analysts with the unique ability towith a later diagnosis of autism can be identi- answer one ofthe most long-standing and chal-fied at least as early as 8 to 10 months, and lenging questions of parents and parent advo-perhaps earlier (Werner, Dawson, Osterling, & cates nationwide: "How can autism be pre-Dinno, 2000). Consequently, behavioral re- vented?" Based on the current analysis, itsearch focusing on specific parent-child rein- should be possible to begin to prevent manyforcement contingencies that establish the ini- cases ofautism immediately by identifying re-tial stages of verbal behavior between birth and inforcement contingencies that might prevent 12 months would be particularly useful in or inhibit the development of verbal behaviorshowing how the precursors of verbal behav- during the period between birth and 18 to 24ior are shaped and precisely what behaviors months and replacing them with reinforcementmay be incompatible with or prevent the ac- contingencies that could establish age-appro-quisition of verbal behavior. Further analysis priate verbal and social behavior.of the role of automatic reinforcement as it re- One important component of ABA preven-lates to the shaping of verbal behavior during tion programs would be to establish, as soonthe first year would also be quite valuable as feasible, a nation-wide network of Applied(Bijou & Baer, 1965; Skinner, 1957; Smith, BehaviorAnalysis screening programs for par-Michael, & Sundberg, 1996; Sundberg & ents and their infants between birth and 24Michael, 2001; Sundberg, Michael, Partington, months that would focus on identifying and& Sundberg, 1996). modifying contingencies and behaviors that A second related line of research would be may interfere with acquisition of age-appro-to investigate the role ofaversive manding and priate verbal behavior. Once these contingen-other avoidance behaviors in preventing the cies are identified, parents could be taught toacquisition ofverbal behavior. Since avoidance replace them with contingencies that will shapebehaviors and aversive manding are strongly age-appropriate verbal and social behavior byimplicated as casual factors in this analysis of age 2 to 3 years. In those cases in which com-language delay, it would be important to ex- plete prevention might not occur, preventionamine the early stages of language acquisition efforts could lead directly into ABA early in-to evaluate precisely how aversive manding tervention programs. For a related discussionand disruptive avoidance behaviors are origi- of behavioral prevention programs, see Drashnally established and how these behaviors may and Tudor (1990, 1993).function to prevent acquisition of appropriate Based upon the success of previous preven-verbal and social behavior. It would also be tion and early intervention programs, there isuseful to analyze why and how avoidance be- a high probability that the more severe symp-haviors are shaped in some children and not toms of autism might never occur (Anderson,others. Avery, DiPietro, Edwards, & Christian, 1987; Begab, Haywood, & Garber, 1981; Bijou,Preventing Autism Now: A Practical Behav- 1983; Birnbrauer & Leach, 1993; Drash, 1992;ioral Strategy that Can Be Implemented Drash & Raver, 1987; Drash, Raver & Murrin,Immediately 1987; Fenske, Zalenski, Krantz, & McClannahan, 1985; Garber, 1988; Guralnick, One of the major goals of both behavioral 1997; Harris, Handleman, Gordon, Kristoff, &and biomedical research in autism during re- Fuentes, 1991; Lovaas, 1987; Menolascino &cent years has been to identify causal variables Stark, 1988; Smith, Groen, & Wynn, 2000).
  14. 14. 18 PHILLIP W. DRASH & ROGER M. TUDORDeveloping a Contingency-based Strategy child, diagnosed as at-risk, achieved relativelyfor Earlier Intervention normal language and behavioral functioning after 10 months of in-office, ABA verbal be- One of the principal goals of contingency- havior therapy consisting of a total of only 52based early intervention programs would be to one-hour sessions (1 to 2 sessions per week)begin ABA intervention programs before the (Drash & Tudor, 1989, pp. 30-31; 1990, pp.repertoires ofaversive manding and disruptive 199-201). In a second case, a 2 1/2-year-oldavoidance behaviors are well established. As nonverbal child, diagnosed with aphasia, shown by several of the cases presented previ- achieved relatively normal language and be-ously, the disruptive and avoidance behaviors havioral functioning after 11 months of in-of-of children diagnosed with autism/PDD are fice, ABA verbal behavior therapy consistingoften well established by 18 months to two of 36 one-hour sessions (1 to 2 sessions peryears. week) (Drash, 2001). If behavioral interventions that are focused The total number of therapy hours providedon the development of appropriate verbal and to each of these two children was only a frac-social behavior and elimination of disruptive tion of that typically provided in a 40-hour-and avoidance behaviors are begun during the per-week, in-home ABA program over a com-first year to 18 months, the probability for to- parable duration. For the first child, the com-tal recovery may be greatly enhanced. Green, parison is 52 hours vs. 1,600 hours, or 3%, andBrennan, and Fein (2002) recently reported on for the second child 36 hours vs. 1,760 hours,a case in which early intensive behavioral treat- or 2%. At present these two cases clearly rep-ment of a 1-year-old child at high-risk for au- resent the exception rather than the rule. How-tism produced total recovery within a period ever, they suggest that, in some cases, both theof three years. This study demonstrated the ef- length and intensity of treatment for youngerfectiveness of ABA intervention for autism at children, especially those considered at-risk,a younger age than has been previously re- may be considerably less than that required forported. older children.Reducing the Number of Treatment Hoursper Week and the Total Length of Treatment Making "Functional Recovery" a Routine and Expected Outcome in ABA Treatment of Since the degree of pre-language or language Young Children with Autismdelay is necessarily small at age 6 to 18 monthsand the incompatible avoidance behaviors usu- As a result of recent advances in the field ofally are not well established, it should be pos- Applied Behavior Analysis, relatively total re-sible to restore young children to "relatively covery or cure is now recognized as a legiti-normal functioning" much more rapidly than mate and obtainable outcome in the behavioralolder children who have well established rep- treatment of autism (Maurice, 1993; Maurice,ertoires of disruptive and avoidance behaviors. Green, & Foxx, 2001; Maurice, Green, & Luce,The Lovaas (1987) program required 2 to 3 1996; McEachin, Smith, & Lovaas, 1993;years of 40-hours-per-week intensive indi- Lovaas, 1987). At present, however, total re-vidual ABA treatment to achieve recovery covery as an outcome remains the exceptionwhen children began treatment at an average rather than the rule in the treatment of autism.age ofthree years. Therefore, ifABA treatment Moreover, some career experts in autism con-is begun between 6 and 18 months, it should tinue to maintain that total recovery is impos-be possible to restore a child to relatively nor- sible (Mesibov, 1997) and appear unwilling tomal functioning within one to two years. consider evidence that indicates children have Our research with children diagnosed as au- totally recovered.tistic, PDD, or at-risk in the age range of 18 The dispute over the term "total recovery"months to 2 1/2 years suggests that, for some greatly detracts from the fact that hundreds ofchildren, a program of far less intensity than a children are daily making excellent progress40-hour-per-week program may be sufficient in ABA treatment programs, and many are, forto produce substantial recovery within one to all practical purposes, substantially recoveringtwo years. In one previously published case, a from autism (Maurice, 2001). To avoid the19-month-old, seriously language-delayed controversy surrounding the term "total recov-
  15. 15. THE ETIOLOGY OF AUTISM 19 ery" we propose the term "functional recov- disorders (4th ed.). Washington, D.C.: Au- ery" that would operationally define the con- thor. dition ofmany children who have made excel- Anderson, S. R., Avery, D. L., DiPietro, E. K., lent improvement in language, intelligence, and Edwards, G. L., & Christian, W. P. (1987). social behavior, but who may or may not be Intensive home-based early intervention described as "totally recovered." Objective with autistic children. Education and Treat- measures might include successful function- ment of Children, 10, 352-366. ing in regular grade, ability to interact appro- Autism Society of America. (2002). Advocatepriately and independently in social situations, (4th ed.) 35, 4. Bethesda, MD: Author.elimination of temper tantrums and other dis- Bailey, A., Phillips, W., & Rutter, M. (1996).ruptive or avoidance behaviors, and normal Autism: Towards an integration of clinical, functioning on standardized tests of language, genetic, neuropsychological and neurobio-intelligence, social adjustment, and academic logical perspectives. Journal ofChild Psy-subjects. This would allow for the establish- chology & Psychiatry & AlliedDisciplines,ment of an objective continuum of treatment 37, 89-126.outcomes, ranging from slight or no improve- Barton-Cohen, S., Allen, J., & Gillberg, C.ment, to partial recovery, to functional recov- (1992). Can autism be detected at 18ery, to total recovery. By describing each cat- months? The needle, the haystack, and theegory in operational terms based on direct, rep- CHAT. British Journal of Psychiatry, 161,licable observations of behavior, much of the 839-843.controversy regarding the effects ofABA treat- Begab, M. J., Haywood, H. C., & Garber, H. I.ment could be avoided, and the realistic ben- (Eds.). (1981). Psychosocial influences inefits of ABA treatment could be more easily retardedperformance (Vols. 1 & 2). Balti-recognized and accepted. more: University Park Press. Bijou, S. W. (1966). A functional analysis of CONCLUSION retarded development. In N. R.. Ellis (Ed.), International Review of Research in Men- Conceptualizing autism as a contingency- talRetardation. New York: Academic Press.shaped disorder of verbal behavior that begins Bijou, S. W. (1983). The prevention of mildduring the first year of life provides a new para- and moderate retarded development. In F.digm for behavioral research and treatment in J. Menolascino, R. Neman, & J. A. Starkthe areas of prevention, earlier intervention, and (Eds.), Curative aspects of mental retarda-recovery from autism. By beginning ABA tion: Biomedical and behavioral advancestherapy during the first 6 to 18 months and fo- (pp. 223-241). Baltimore: Brookes.cusing on modification of the specific contin- Bijou, S. W., & Baer, D. M. (1965). ChildDe-gencies of reinforcement that may prevent or velopment II: Universal stage of infancy.interfere with acquisition of verbal behavior, Englewood Cliffs, NJ: may be possible to prevent many cases of Bijou, S. W., & Ghezzi, P. M. (1999). The be-autism and reduce the debilitating effects of havior interference theory of autistic behav-many others. The duration and intensity of ior in young children. In P. M. Ghezzi, W.treatment may be reduced, and "functional re- L. Williams, & J. E. Carr (Eds.), Autism:covery" from autism might become the norm Behavior analytic perspectives (pp. 33-43).and expected outcome ofABA treatment. Reno, NV: Context Press. Bimbrauer, J. S., & Leach, D. J. (1993). The Murdoch early intervention program after REFERENCES 2 years. Behaviour Change, 10, 63-74. Bruner, J. (1983). Childs talk: Learning to useAlexander, D., Cowdry, R. W., Hall, Z. W., & language. New York: W. W. Norton. Snow, J. B. (1996). The state of science in Carr, E. G., & Durand, V. M. (1985). Reducing autism: A view from the National Institutes behavior problems through functional of Health. Journal ofAutism and Develop- communication training. Journal ofApplied mental Disorders, 26, 117-119. Behavior Analysis, 18, 111-126.American Psychiatric Association. (1994). Di- Carr, E. G., & Durand, V. M. (1986). The so- agnostic and statistical manual of mental cial-communicative basis of severe behav-