This study examined relationships between general adaptive behavior and the degree of community independence displayed by 272 adults with intellectual disabilities. Specifically, the Adaptive Behavior Assessment System—Second Edition (ABAS-II; Harrison & Oakland, 2003) was completed for each participant and compared with actual levels of work and residential independence. The participants' adaptive behavior accounted for 40%–43% of the variance in their work and residence independence. The results from this field-based study indicated that participants who displayed higher levels of adaptive behavior generally worked and lived more independently. Participants with the lowest general adaptive behavior required the highest degree of community supports. Implications of these findings are discussed.
An intellectual disability is a disability characterized by significant limitations both in intellectual functioning and adaptive behavior, as expressed in conceptual, social, and practical adaptive skills (American Association on Mental Retardation, 2002). Intellectual disabilities constitute the most frequent developmental disability and rank first among chronic conditions that cause major limitations in daily living and work skills among persons in the United States and abroad (Hall et al., 2005). Approximately 2.5% of the U.S. population is diagnosed with an intellectual disability (Sattler, 2002).
Individuals with an intellectual disability acquire information and skills at a delayed rate compared with their peers without disabilities (Routh, 1996). For example, young children with this disability generally are delayed in learning to toilet train, speak, walk, and care for their early-appearing personal needs (e.g., dressing and eating). Later, in school, they are likely to acquire academic skills at a slower than average rate and require additional educational supports (Bildt, Sytema, Kraijer, & Minderaa, 2005). Following school, they often display difficulty obtaining and maintaining employment, living independently, developing and sustaining relationships with peers who are not disabled, caring for their physical needs, and displaying other needed adaptive behaviors (Kampert & Goreczny, 2007). Thus, persons with intellectual disabilities, especially those with more severe forms, are likely to require special education and related services, including assistance and support, to acquire and display daily living skills.
Educators, parents, and others responsible for assisting persons with intellectual disabilities can anticipate providing more intensive supports to those who display lower levels of independence. A limited repertoire of independently displayed adaptive behaviors may result in an increased need for vocational supervision, residential custodial care, and other forms of supports that may lead to community restrictions and increased dependence on others (Lerman, Apgar, & Jordon, 2005). Thus, educational and other supportive efforts often are needed to help persons with intellectual disabilities acquire greater independence in the display of their adaptive behaviors, including those that are likely to enhance their eventual vocational and living arrangements.
Efforts to promote the development of adaptive behaviors are consistent with public policy that advocates for the social integration of individuals with disabilities into natural community environments rather than institutional settings (Nihira, 1999). Educational methods that directly develop and reinforce adaptive behaviors have been found to promote personal independence and, thus, allow persons with intellectual disabilities to be more engaged in community settings (Ditterline & Oakland, 2009; Kennedy, 2001).
In its 1992 definition, the American Association on Mental Retardation (AAMR; now the American Association on Intellectual and Developmental Disabilities) identified the following 10 skills as important attributes of adaptive behavior: communication, community use, functional academics, school–home living, health and safety, leisure, self-care, self-direction, social, and work. These 10 skills also constitute qualities important to the diagnosis of an intellectual disability in the Diagnostic and Statistical Manual of Mental Disorders—Fourth Edition, Text Revision (DSM-IV TR; American Psychiatric Association, 2000). The AAMR's 2002 definition attempted to further clarify the concept of adaptive behavior by defining it as “the collection of conceptual, social, and practical skills that have been learned by people in order to function in their everyday lives” (p. 73). Thus, this definition emphasizes three broad skill domains (i.e., conceptual, social, and practical skills). The 10 previously cited skill areas have been linked conceptually with one of the three domains (AAMR, 2002; Harrison & Oakland, 2003).
Schalock (1999) suggested that,
Based on a model of personal competence, the focus of assessment in the field of mental retardation should be related to the performance domains of practical, conceptual, and social skills. [He] also suggested that developing this approach to assessment would involve…[the] use of standardized instruments…to document a person's functioning across the overall competence domains. (p. 216)
The research we did for this study provides information relative to general adaptive functioning and its subdomains. Studies of this kind may assist individuals with intellectual disabilities by allowing those working with these individuals to assist them in prioritizing skills needed to promote community independence and reduce the intensity of provider supports. As Thompson, McGrew, and Bruininks (1999) noted,
A more precise understanding of the structure of adaptive behavior would enable policy makers to make funding decisions based on…a more explicit understanding of the types and nature of support services people with mental retardation truly need…[and] provide planning teams with an empirically defensible basis on which to prioritize educational and habilitation goals and activities for individuals. Areas of relative strength could be enhanced and capitalized on while areas of relative weakness could be targeted for improvement and support…Identifying empirically supported, essential domains of adaptive behavior would enable educators and adult provider organizations to monitor the progress of individuals and make decisions regarding their program's effectiveness. (p. 17)
Knowledge of adaptive behavior relative to residential and vocational performance is essential to understanding the supports required by individuals with intellectual disabilities.
Relationships among adaptive behaviors and vocational and residential independence among adults with intellectual disabilities are likely to be reciprocal. Decisions as to the responsibilities assumable by persons with intellectual disabilities may be impacted by knowledge of their adaptive behavior. In addition, adaptive behaviors may be promoted when persons with intellectual disabilities are provided more vocational and residential independence. Thus, an understanding of relationships among adaptive behaviors and vocational and residential independence among adults with intellectual disabilities may eventually assist in better understanding this reciprocal relationship. Our purpose in this research was to examine relationships among adaptive behavior and vocational and residential independence among adults with intellectual disabilities.
Participants include 272 adults (52% men) who were receiving support services from a nonprofit residential or day treatment center. All participants displayed moderate intellectual disabilities. Participants ranged from 22 through 72 years, with a mean of 43 years (SD = 12). Among the participants, 222 were White, 46 were Black, 3 were Latino, and 1 was Asian. A university institutional review board and the participating agency's Human Rights Advocacy Committee approved the research protocol.
Ten support coordinators (case managers with undergraduate degrees who organized external support required by each participant relative to their vocational and community goals) assisted in this study. Support coordinators had daily service management responsibility for the participants. They requested and obtained informed consent from each participant assigned to his/her caseload. Support coordinators were trained by the first author (S.W.) on how to explain the informed consent to the participants in a manner that minimized coercion and emphasized voluntary participation. Parents–guardians were informed in writing about the study, and all participants qualified as legally competent.
The support coordinators also completed the adult form of the Adaptive Behavior Assessment System—Second Edition (ABAS-II; Harrison & Oakland, 2003) on each participant after receiving training on ways to complete the measure. Support coordinators also identified the type of supports provided in the participant's vocational and residential living arrangement.
The ABAS-II (Harrison & Oakland, 2003) provides a comprehensive assessment of adaptive behavior and skills for individuals from birth to 89 years. Consistent with the definition and specifications of the AAMR (1992, 2002) and DSM–IV TR (American Psychiatric Association, 2000), the ABAS-II was developed to measure 10 specific adaptive skills in three domains: conceptual (communication, functional academics, and self-direction skills), social (leisure and social skills), and practical (community use, home or school living, health and safety, and self-care). Work skills also are assessed but not included in any of the three domains. Domain scores are used to derive the general adaptive composite (GAC) score.
Respondents (e.g., support coordinators) completed the ABAS-II by indicating for each item if the individual was able to independently perform an activity and, if so, how often (never, sometimes, or always) when needed. The ABAS-II was standardized on a sample of 7,370 persons representing the English-speaking U.S. population from birth through 89 years, stratified by sex, race–ethnicity, and educational levels consistent with the 2000 U.S. census. External evaluations of the ABAS-II (e.g., Meikamp & Suppa, 2005; Rust & Wallace, 2004; Spies & Plake, 2005) have reported it to have a high level of reliability and present substantial validity evidence.
Support coordinators also rated each participant's levels of vocational and residential independence. Terminology used for these categories was consistent with support levels funded through the state reimbursement system and was understood by the support coordinators responsible for identifying the type of supports provided to the participants. Participants' work independence fell into one of the following four categories, identified in decreasing order of independence: (a) independent—working independently in a competitive employment setting; (b) supported—working with daily support from a job coach in a competitive employment setting where the coach assisted the individual approximately 10% of the time the individual was at the job site, (c) sheltered—working in a sheltered workshop designed for individuals with disabilities where multiple support staff members were available 100% of the time and individuals were paid for their work, and (d) nonwork—participating in an unpaid training setting where multiple support staff members were available 100% of the time. Participants' residential independence fell into one of the following four categories identified in decreasing order of independence: (a) independent—living independently in the community (e.g., living in an apartment or home) with weekly supports from a supported living coach who was available approximately 10% of the time the individual was at the residence, (b) community—living in the community with a supported living coach who was available 100% of the time the individual was at the residence, (c) group—living in a group home designed for individuals with disabilities where multiple support staff were available 100% of the time the individual was at the residence, and (d) intermediate care facility—living in a residential treatment setting.
Pearson correlations were used to examine the strength of relationships among adaptive behavior and degree of vocational and residential independence. A Bonferroni correction of p < .0125 was used to help correct for the high correlation among the three domain scores. η2 was used to estimate the proportion of variance in vocational and residential independence accounted for by adaptive behavior. We used analysis of variance followed by posthoc least significant difference of p = .01 to examine group differences.
Vocational Independence and Adaptive Behavior
All correlations among adaptive behavior and vocational independence were significant: GAC, r(270) = .629, p < .001; conceptual domain, r(270) = .610, p < .001; social domain, r(270) = .576, p < .001; and practical domain, r(270) = .634, p < .001. The GAC accounted for 42% of the variance in vocational independence (see Table 1).
Levels of adaptive behavior differed for the four work groups, as reflected in the GAC, F(3, 268) = 65, p < .001; and the three adaptive domains: conceptual, F(3, 268) = 63, p < .001; social, F(3, 268) = 48, p < .001; and practical, F(3, 268) = 68, p < .001.
With the exception of independent and supported work environments, mean scores on the GAC and three domains were rank ordered, with those working independently and in supported settings generally displaying the highest adaptive behavior, followed by those working in sheltered and nonwork settings. Differences between contiguously ranked work groups were significant for the GAC (p < .001), except for working independently and in supported settings (p = . 962); for the conceptual domain (p < .001), except for working independently and in supported settings (p = .706); for the social domain (p < .001), except for working independently and in supported settings (p = . 727); and for the practical domain (p < .001), except for working independently and in supported settings (p = . 714).
Residential Independence and Adaptive Behavior
All correlations between adaptive behavior and residential independence were significant: GAC, r(270) = .651, p < .001; conceptual domain, r(270) = .596, p < .001; social domain, r(270) = .672, p < .001; and practical domain, r(270) = .645, p < .001. The GAC accounted for 46% of the variance in residential independence (see Table 1).
Levels of adaptive behavior differed for those living in the four residential settings as reflected in the GAC, F(3, 268) = 74, p < .001; and the three adaptive domains: conceptual, F(3, 268) = 52, p < .001; social, F(3, 268) = 65, p < .001; and practical, F(3, 268) = 73, p < .001.
Mean scores on the GAC and three domains were rank ordered, with those living independently displaying the highest adaptive behavior, followed by those living in community, group, and residential treatment settings. Differences between contiguously ranked work groups were significant for the GAC (p < .001), except those living in community and group settings (p = .106); conceptual domain (p < .001), except those living in community and group settings (p = .072); social domain (p < .001), except those living in community and group settings (p = .106); and practical domain (p < .001), except those living in community and group settings (p = .231) (see Table 2).
Public policies that emphasize deinstitutionalization, community integration, and suitable work and residential environments have substantially changed and generally improved the lives of many persons with disabilities over the last 20 years (Cummins, 2001). These policies have advocated that people with disabilities should work and reside as independently as possible (Jacobson, Mulick, & Foxx, 2005).
A primary purpose of this study was to examine relationships between adaptive behavior and degree of independence displayed by adults with intellectual disabilities in their work and residential settings. The participants' adaptive behavior and their degree of independence were strongly related. For example, the participants' general adaptive behavior accounted for approximately 42% and 46% of the variance associated with their vocational and residential independence, respectively. These findings are consistent with previous research that reported a moderate relationship between adaptive behavior and personal independence for individuals with disabilities (Bildt, 2005).
The adaptive behavior of those working independently and in supportive settings generally did not differ. In addition, the adaptive behavior of those living in community and group settings generally did not differ. Thus, the expectation that individuals who differed in their adaptive behavior and skills also would differ in their work and living settings was not supported.
This finding may have been due to a small sample size for those working independently and because adaptive behavior accounts for a little less than 50% of the variance in work and residential settings. Additional research that provides a clearer understanding of similarities and differences between those working independently and in supportive settings as well as those living in community and in group settings may provide insights as to qualities other than adaptive behavior that contribute importantly to work and residential living.
Adults with intellectual disabilities who display lower levels of autonomy generally require a higher level of external support. Some may view the development of adaptive behavior as a needed precursor to the attainment of higher levels of independence at work and home, resulting in a reduced need for external support. Thus, programs that promote the development of adaptive behavior and skills are important to the success of achieving the goal of greater independence.
The development of adaptive behavior and greater autonomy at work and home is likely to be reciprocal. Each influences the other. Thus, although information from measures of general adaptive behavior may be useful when initially placing persons in work and residential settings, their personal engagement in suitable settings should be used to increase a person's adaptive behavior and skills.
Implications From These Results
Findings from this study with adults with intellectual disabilities supported the following implications. Information from measures of adaptive behavior, although mandatory when making a diagnosis of intellectual disability, also may be useful when initially deciding on placement in vocational and residential settings. Although the selection of the most viable vocational and residential settings requires various data, information from adaptive behavior, at least as measured by the ABAS-II, can likely assist in these efforts. Moreover, data from the periodic readministration of the same measure of adaptive behavior can help evaluate changes. These changes are most likely to be seen in item data, not in standard scores at the subtest, domain, or general adaptive levels. In their discussion of measures of adaptive behavior, Sattler and Hoge (2006) noted that “individual items provide information about what the [individual] can and cannot accomplish on the test” (p. 440). Indeed, “it is better to use raw scores rather than standard scores for estimating the progress of [individuals] with severe or profound disabilities” (p. 440).
Efforts that are successful in promoting the acquisition and retention of adaptive skills in persons with intellectual disabilities are likely to be important to their vocational and residential independence as well as community integration. Adaptive skills such as asking for directions, setting an alarm clock, cooking simple meals, interpreting a public bus schedule, and maintaining one's finances are necessary for independent functioning. The use of an instructional curriculum designed to promote the development of these and other daily living skills needed by persons to become more independent is likely to be cost effective, in part, by decreasing their dependence on service providers as they become older.
The acquisition of adaptive skills is most likely to occur when service providers, (e.g., supported living providers and job coaches), teachers, family members, and others, together with the client, help design and implement individualized interventions (Woolf, 2006). The adaptive skills should be narrowed to those that are most functional and needed immediately. Skill development is likely to be most effective when the behaviors are specific, are practiced in the environments in which they have functional value, are seen by the client and others as important, and have inherent reward value. This effort requires a shift from an emphasis on adaptive behavior and the three adaptive domains to specific adaptive skills. Efforts to promote specific skill development will be more successful than efforts to promote general adaptive behavior.
This research involved many individuals with intellectual disabilities who were successfully employed and lived independently. Individuals who are more independent generally display higher levels of adaptive skills. Support providers working at sheltered workshops and institutional settings where individuals are not as independent may target the development of adaptive behavior as a primary goal for each client. Sheltered workshops and institutional residential settings represent the most restrictive placement for individuals with disabilities. Moving these clients from a highly supported setting to a more inclusive community setting should be a goal for each client. Direct instruction that emphasizes adaptive skills development eventually may lead to clients requiring fewer supports.
Participants in this study received services from one agency. Thus, the degree to which relationships between adaptive behavior and work and residential living are found in adults with intellectual disabilities in other agencies is unknown and needs to be determined. In addition, the degrees of independence displayed through work and residential living are likely to be similar. For example, those working independently also are likely to live independently. Thus, the placement of participants in vocational and residential groups is unlikely to be independent. In addition, the inclusion of more participants who are independent in their work may have strengthened this study. The degree to which the 10 specific skills impact work and residential independence also should be explored.
Editor-in-Charge: Steven J. Taylor
Steve Woolf, PhD,BCBA-D, Vice President of Operations and Program Development, BEACON Services, Milford, MA 01757. Christine Merman Woolf, PhD, NCSP (E-mail: Christine.Woolf@Capella.edu), School Psychology Program Coordinator and Director of Clinical Training for the School Psychology Specialization, Capella University, Harold Abel School of Social and Behavioral Sciences, Department of Psychology, Minneapolis, MN 55402. Thomas Oakland, PhD, Professor, University of Florida, School of Special Education, School Psychology, and Early Childhood Studies, Gainesville, FL 32611.