Chapter 15

• Intellectual disability is defined as significantly subaverage general intellectual functioning, existing concurrently with deficits in adaptive behavior manifested during the developmental period, which adversely affects a child’s educational performance.
• The term "idiots" was used in the early times for those with severe cognitive deficits.
• In the 19th century, the term "imbecile" was given as a label for a less severe degree of intellectual disability.
• For mild intellectual disability, the terms "feebleminded" and "simpleton" were used.
• These terms were used by professionals in medicine, psychology, and education to refer to intellectual disabilities, although nowadays, these labels are seen as inappropriate and stigmatizing.
• The range of intellectual disability includes mild, moderate, severe, and profound levels.
• Majority of children with intellectual disability (85%) fall within the mild range (IQ range from 55 to 75), while those children whose IQ is on lower ranges ( IQ less than 40) often have multiple disabilities.
• These terms were replaced by mental retardation, which at the time was seen as more appropriate.
• In 2007, the American Association on Mental Retardation changed its name to the American Association of Intellectual and Development Disabilities (AAIDD), consistent with the term intellectual disability now deemed as more appropriate.
• The Individuals with Disabilities Education Act (IDEA) defines intellectual disability as "significantly subaverage general intellectual functioning, existing concurrently with deficits in adaptive behavior manifested during the developmental period, which adversely affects a child’s educational performance."
• Three criteria for diagnosis of intellectual disability are specified in IDEA: significantly subaverage intellectual functioning, deficits in adaptive behavior, and adversely affects a child’s educational performance.
• Significantly subaverage intellectual functioning in IDEA refers to a score of two or more standard deviations below the mean on a standardized intelligence test, approximately an IQ score of 70 or lower.
• AAIDD’s definition of intellectual disability specifies significant limitations in both intellectual functioning and adaptive functioning which should occur before the age of 18 years.
• Problems during birth, such as a baby not getting enough oxygen, can result in an intellectual disability.
• American Psychiatric Association (2013) defines intellectual disability as deficits in general mental abilities, including reasoning, problem solving, planning, abstract thinking, judgement, academic learning, and learning from experience.
• Extreme malnutrition, not getting appropriate medical care, or being exposed to poisons like lead or mercury can also cause intellectual disabilities.
• Genetic conditions such as Down syndrome, Fragile X syndrome, and phenylketonuria (PKU) are examples of conditions that can cause an intellectual disability.
• Diseases like whooping cough, the measles, or meningitis can cause intellectual disabilities.
• Individuals with intellectual disability are classified according to their IQ scores which could range from 70 (plus or minus 5 points of measurement error) to below 20.
• The characteristics of those with intellectual disability whose IQ score are within this range vary widely.
• Deficits in intellectual functioning and adaptive behavior must occur during the developmental period, which differentiates intellectual disabilities from other disabilities of cognitive impairment such as traumatic brain injury.
• There are five assumptions essential for understanding and applying AAIDD’s definition of intellectual disability: limitations in present functioning must be considered within the context of the person’s community environment with regard to age, peers, and culture; valid assessment considers cultural and linguistic diversity as well as differences in communications, sensory motor, and behavioral factors; limitations often coexist with strengths within the individual; limitations are described for the purpose of profiling an individual’s needed support; and the life functioning of the person w
• Complications during pregnancy, such as a problem with the way the baby’s cells divide, can result in an intellectual disability.
• Significant difficulty with tasks for daily living (adaptive behavior) is a characteristic of intellectual disabilities.