The chapter describes the history of the label “intellectual disability” and traces the changes in the definition of this construct through history ending with a discussion of the current conceptualization of intellectual disability. Assessment of intellectual ability and adaptive behavior is discussed in terms of understanding how these skills are measured as well as caveats that must be considered when assessing these skills. Different classification systems (e.g., etiological, severity of deficits, education, levels of support) are presented. The history of treatment of individuals with intellectual disability is traced through history.

The chapter reviews the prevalence and different known etiologies of intellectual disability. Individuals with intellectual disability are described in terms of their learning, social, and behavioral characteristics, The educational placements, programming options, instructional strategies, and transition planning needs of students with intellectual disabilities are presented. The needs of young children and adults with intellectual disability are discussed as are family and diversity issues. The chapter concludes with information about the use of assistive technology with individuals with intellectual disabilities and what the future may hold for individuals with intellectual disabilities. 

Learning Objectives:

• Summarize the key elements of the AAIDD definitions of intellectual disability from 1961 to 2010.
• Describe the concepts of intellectual ability and adaptive behavior.
• Explain four ways of classifying individuals with intellectual disability.
• Provide examples of pre-, peri-, and postnatal causes of intellectual disability.
• Outline society’s reaction to and treatment of individuals with intellectual disability.
• Identify representative learning and social/behavioral characteristics of persons with intellectual disability.
• Define functional curriculum, functional academics, and community-based instruction.
• List the key features of the following instructional strategies: task analysis, cooperative learning, and scaffolding.
• Describe the goals of early intervention for young children with intellectual disability.
• Characterize contemporary services for adults with intellectual disability.

Lecture Outline:

1. Defining Intellectual Disability
   
   1. Intellectual functioning
      
      1. Generally measured with IQ testing.
   2. Adaptive behaviors
      
      1. Refers to an individual’s ability to meet the social requirements of his or her community that are appropriate for his or her chronological age; it is an indication of independence and social competency.
   3. Developmental period
      
      1. Typically extends from birth to age 16 or 18
   4. Adaptive skill areas
      
      1. Skill areas in which most people participate: communication, self-care, home living, social skills, community use, self-direction, health and safety, functional academics, leisure, and work.
   5. The AAIDD, founded in 1876, has amended its definition of mental retardation several times over the decades. In 1987, the American Association of Mental Deficiency (AAMD) changed its name to the American Association on Mental Retardation (AAMR). In 2007, the Association changed its name to the American Association on Intellectual and Developmental Disabilities (AAIDD) which is consistent with European and Canadian terminology. The U.S. Department of Education uses the term mental retardation and both are used interchangeably in this textbook.
      
      1. 1961 AAMR definition
         1. “Subaverage general intellectual functioning which originates during the developmental period and is associated with impairments in adaptive behavior.”
         2. Definition is based on IQ scores that fall at least one standard deviation below the norm and an individual’s ability to meet expected social requirements. Refers to students who exhibit delays in the developmental period from birth to approximately age 16.
      2. 1973 AAMR definition
         1. “Significantly subaverage general intellectual functioning existing concurrently with deficits in adaptive behavior, and manifested during the developmental period.”
         2. Emphasis on “significantly subaverage” based on IQ scores that fall at least two standard deviations below the norm.
         3. Expanded the concept of adaptive skills to include standards of personal independence and social responsibility within the context of the person’s age and sociocultural group.
         4. Emphasis on reducing the number of students identified with mental retardation based solely on their IQ score.
      3. 1983 AAMR definition
         1. “Significantly subaverage general intellectual functioning resulting in or associated with concurrent impairment in adaptive behavior and manifested during the developmental period.”
         2. Suggested using a flexible range of IQ scores (70-75) for eligibility rather than a strict cutoff at 70.
      4. 1992 AAMR definition
         1. “Significantly subaverage intellectual functioning, existing concurrently with related limitations in two or more of the following applicable adaptive skill areas: communication, self-care, home living, social skills, community use, self-direction, health and safety, functional academics, leisure, and work. Mental retardation manifests before age 18.”
         2. Important changes included: the use of culturally valid assessments, limitations in adaptive skills occur within the context of community environments, limitations in specific adaptive areas often coincide with strengths in other adaptive areas, and the life functioning of a person with intellectual disability will generally improve with appropriate supports.
         3. This definition stresses functioning within one’s community rather than focusing on clinical aspects such as IQ score or adaptive behavior.
      5. 2002 AAMR definition
         1. “Mental retardation is a disability characterized by significant limitations both in intellectual functioning and in adaptive behavior as expressed in conceptual, social, and practical adaptive skills. This disability originates before age 18.”
         2. The current definition includes five main assumptions: limitations in functioning must be considered in the context of the individual’s environments, valid assessments must be culturally sensitive, limitations often coexist with strengths, an important purpose of describing limitations is to develop appropriate supports, and the life functioning of a person with intellectual disability will generally improve with appropriate supports.
         3. Acknowledges the significance of adaptive behaviors and systems of support.
      6. 2010 AAIDD definition
         1. The term mental retardation is replaced by the more contemporary label, intellectual disabilities.
         2. Developed by a committee of eighteen medical and legal scholars as well as policymakers, educators, and other professionals, the 2010 definition emphasizes the abilities and assets of individuals with intellectual disabilities rather than their deficits or limitations.
         3. Intellectual disabilities are viewed as a state of functioning rather than an inherent trait. As in earlier definitions, one of the goals of the 2010 definition is to maximize support services so as to allow persons with intellectual disabilities to participate fully in all aspects of daily life.
2. Assessing Intellectual Disability
   
   1. Assessing Intellectual Ability (IQ testing)
      
      1. Assessment tools:
         1. Wechsler Intelligence Scale for Children, 4th Edition (WISC-IV)
         2. Stanford-Binet Intelligence Scale (5^th Ed.)
      2. Potential problems:
         1. Potential for cultural bias within assessment measures
         2. Flexibility of IQ scores- IQ may change over time
         3. Overemphasis on IQ score- adaptive behaviors must also be considered
   2. Assessing Adaptive Behavior
      
      1. Considers the context of the individual’s environment and cultural influences
      2. Assessment tools:
         1. AAMR Adaptive Behavior Scale-School
         2. AAMR Adaptive Behavior Scale-Residential and Community
         3. AAIDD Diagnostic Adaptive Behavior Scale is being developed
3. Classification of Individuals with Intellectual Disabilities
   
   1. Etiological perspective
      
      1. Assumes that intellectual disability is a consequence of disease processes or biological defects such as rubella or maternal syphilis or chromosomal abnormalities such as Down syndrome or metabolic disorders such as PKU.
   2. Intellectual deficits
      
      1. Classification based on IQ score. Classification labels include mild, moderate, and severe intellectual disability.
   3. Educational perspective
      
      1. Includes the use of outdated terms such as educable mentally retarded and trainable mentally retarded to distinguish a children’s level of ability to learn academic or employment skills.
         1. These terms are now considered pejorative and should not be used.
   4. Levels of supports
      
      1. New definitions for intellectual disability have shifted to an emphasis on the level of supports that an individual needs rather than IQ score.
         1. intermittent support
         2. limited support
         3. extensive support
         4. pervasive support
4. Brief History of the Field
   
   1. Early Civilizations
      
      1. Early civilizations such as the Greek and Roman empires valued physical and mental strength and were reported to practice infanticide with children thought to be defective.
   2. The Middle Ages
      
      1. The social force of religion brought a more charitable view of disability into vogue and churches established asylums for the “children of God.” Fear and superstition were rampant and people with intellectual disabilities were often thought to possess demonic powers from Satan.
   3. Early optimism (early nineteenth century)
      
      1. Itard and Seguin brought European ideas to America regarding the education of people with intellectual disabilities. In 1876, the Association of Medical Officers of American Institutions for Idiotic and Feeble-minded Persons was established.
   4. Protection and pessimism (late nineteenth and early twentieth centuries)
      
      1. This era witnessed the American development of large, isolated institutions designed to segregate people with intellectual disabilities. The understaffed institutions focused on custodial care rather than education and training. The deinstitutionalization movement began in the 1970s to move people with intellectual disabilities into the community.
   5. Emergence of public education for students with intellectual disability
      
      1. In the early part of the twentieth century, schools were developed for students with intellectual disability although they were often isolated and segregated. Classes were generally available to students who were considered higher functioning and did not provide services for students with severe intellectual disability. Legislation and professional opinion has shifted toward less restrictive and more integrated educational placements for students with intellectual disability.
5. Prevalence of Intellectual Disability
   
   1. Approximately 7% of all students with disabilities
   2. Less than 1% of total school population
   3. 1.6% of preschoolers
   4. Majority of those identified have mild intellectual disability
6. Etiology of Intellectual Disabilities
   
   1. Causes
      
      1. Prenatal (before birth)
         1. Chromosomal: Down syndrome, Fragile X syndrome, , Turner syndrome
         2. Metabolic and nutritional disorders: Phenylketonuria, Tay Sachs disease, galactosemia, Prader-Willi syndrome
         3. Maternal infections: Rubella (German measles), sexually transmitted diseases, Rh incompatibility, toxoplasmosis, cytomegalovirus
         4. Environmental factors: Exposure to drugs and alcohol (fetal alcohol syndrome), maternal malnutrition and healthcare issues
         5. Unknown influence: Cranial malformations such as anencephaly, microcephaly, and hydrocephalus
      2. Perinatal (during birth)
         1. Gestational disorders: Low birth weight, premature birth
         2. Neonatal complications: Oxygen deprivation, birth trauma, breech birth, lengthy birth process
      3. Postnatal (after birth)
         1. Infections and intoxicants: meningitis, encephalitis, lead poisoning, mercury
         2. Environmental factors: child abuse and neglect, adverse living conditions, poor nutrition, inadequate health care, lack of early cognitive development
   2. Prevention levels
      
      1. Primary (before onset or occurrence)
         1. Prenatal care: nutrition, check-ups, vitamins
         2. Genetic testing: amniocentesis, chorionic villus sampling
         3. Ultrasound: helpful for identifying physical defects
      2. Secondary (reducing risk factors)
         1. Newborn screening: PKU, galactosemia
      3. Tertiary (interventions)
         1. Aimed at maximizing the quality of life for a person with a disability: early intervention programs, educational programs, supports and services
7. Characteristics of Individuals with Intellectual Disabilities
   
   1. Learning characteristics:
      
      1. Attention
      2. Memory
      3. Academic performance
      4. Motivation
      5. Generalization
      6. Language development
   2. Social and behavioral characteristics:
      
      1. Interpersonal skills
      2. Socially appropriate interactions
      3. Friendships
8. Education Considerations
   
   1. Least Restrictive Environment
   2. Functional academics/functional curriculum
   3. Instruction for pupils in the skills they will require for successful daily living after leaving school in the following domain areas: self-help skills, socialization, communication, vocational training, and access to community resources. Real-life applications of reading and mathematics are taught.Community-based instruction
      
      1. Application of skills through real-life situations in the community
   4. For some students the standards-based general education curriculum may be appropriate
   5. IEP teams must consider:
      
      1. Student and family preferences, student’s age and years left in school, rate of learning, current and future settings, other skill needs
9. Instructional Strategies
   
   1. High expectations: Teachers should have high expectations for all their students especially their students with disabilities
   2. Task analysis: A complex behavior or task is broken down and sequenced into steps
   3. Cooperative learning: An instructional methods that places small groups of students together in order to jointly accomplish a common goal
   4. Scaffolding: Support is given to a student learning a new task and the support is withdrawn as the student becomes more independent and no longer needs the support.
   5. Inclusion strategies: Modify instruction, materials, and assessments, teach organizational skills, monitor progress of all students, collaborate with families
10. Services for Young Children with Intellectual Disability
    
    1. Early intervention can be defined as the services and supports rendered to children with disabilities or those who evidence risk factors, younger than age 5, and their families. Early Intervention services may include infant stimulation programs and programs to foster early academic skills and are generally family- centered.
    2. Individualized services that are part of a comprehensive and coordinated effort to enhance development in all domains.
11. Transition into Adulthood
    
    1. Transition to adulthood is an exciting time in the lives of many families, including those who have members with intellectual disabilities. Transition planning must occur via the IEP and must consider:
       
       1. Independent living: The home and self-care skills needed to live independently
       2. Employment
          1. Sheltered workshop: job training provided in segregated facilities
          2. Supported competitive employment: the individual with a disability works alongside nondisabled employees
          3. Job coach: provides on-the-job assistance to support the worker with an intellectual disability
12. Adults with Intellectual Disability
    
    1. May need supports and services in order to enjoy full participation in their community. Key concepts for working with adults with an intellectual disability include:
       
       1. Integration in all aspects of daily life with nondisabled peers including training, school, employment, leisure, and living arrangements.
       2. Self-determination: the decision-making capacity must be fostered to encourage people with intellectual disabilities to participate in decisions that affect their lives
       3. Self-advocacy: encourage people with intellectual disabilities to advocate for their own wants and needs
13. Family Issues
    
    1. Families with a child with an intellectual disability may experience a wide range of concerns and often rely on a support network made up of friends and family members in addition to parent organizations and professional groups. Many organizations offer support for families of children with disabilities.
14. Issues of Diversity
    
    1. Overrepresentation of minority students in special education programs is a problem across the country and may be due, in part, to:
    2. Culturally biased assessment tools and practices that do not evaluate a student’s true knowledge and potential
    3. Teacher expectations that may vary from a student’s cultural experiences
15. Technology and Individuals with Intellectual Disability
    
    1. Should have access to low-tech, mid-tech, and high-tech assistive technology
    2. Most common technologies used
       
       1. Computers
       2. Augmentative and alternative communication (AAC) devices
       3. Self-operated prompting devices
16. Trends, Issues, and Controversies
    
    1. Genetic testing: Genetic testing may diagnose unborn children with disabilities that may lead to ethical and moral decisions
    2. Quality of life: Recent controversies regarding the quality of life for individuals with severe disabilities and who has the right to decide these issues for another person
    3. Attitudinal changes: Changes in legislation, technology, medicine, and educational practices are altering social and cultural beliefs regarding disability and allow people with disabilities to participate in society as equal members
    4. Technology and medical advances: These advances affect the lives of most people and may create new opportunities for people with disabilities
    5. Inclusive education: Students with intellectual disabilities are increasingly receiving some or all of their education in the regular education classroom
    6. Increased self-advocacy and self-determination: Increased self-advocacy and self-determination leads to people with intellectual disability having greater control over their own lives