Intellectual Disability

Intellectual Disability Definition

Intellectual disability is used in reference to a person who has limitations or conditions, for whom certain functions are found to be more difficult in comparison to someone without those limitations. Intellectual disabilities are often diagnosed in childhood, as most of the symptoms can be identified in the developmental stages of learning to walk or talk. The Diagnostic and Statistical Manual of Mental Disorders 5 (DSM-5) defines someone who has below-average abilities in social and practical ideas as having an intellectual disability (2013).

It is not only a child's difficulty with learning to walk or talk that can categorize them as having an intellectual disability. There are symptoms to identify before a diagnosis can be made.

Intellectual Disability Symptoms

Symptoms of intellectual disabilities can manifest in several ways. The National Down Syndrome Society (NDSS) mentions that behaviors such as trouble with remembering, talking much later in age, problems understanding social rules, or consequences of actions can be early signals that there may be an intellectual disability present. As these children grow, actions such as planning, reasoning, and judgment can be difficult areas to learn and comprehend (NDSS.org, 2022). As the child ages, the symptoms or behavior is described as having trouble with taking care of one's self.

These symptoms alone are not the sole way of diagnosing an intellectual disability. So what else is used? Intelligence testing or IQ testing is implemented in diagnosing intellectual disabilities.

Intellectual Disability Test

IQ testing is important to solidify suspicions of intellectual disabilities, so as not to rely solely on behavioral observations. The IQ level is also very important and shows the severity of intellectual disability in categories like borderline, mild, moderate, severe, and profound (Myers' Psychology for AP, 2012). Those with intellectual disabilities are said to have an IQ below 70, in addition to being unable to meet the basic requirements of taking care of themselves. Myers also states that only 1 percent of Americans meet these criteria; of that group, 50 percent are males (2012). These IQ levels can dictate or correspond to a person's abilities both in life and education. The chart below includes the levels of IQ that are associated with life adaptations.

(Myers' Psychology for AP, 2012)

IQ testing is incredibly important to the diagnosis of an intellectual disability and goes hand-in-hand with displayed symptoms and behaviors. Once the IQ testing is finished and combined with the observed behaviors, there is a question to be answered.

What type of intellectual disability is being observed?

Types of Intellectual Disabilities

Certain disorders such as attention deficit hyperactivity disorder (ADHD) are often assumed to be intellectual disabilities. This is incorrect. There are blurred lines between what a learning disability is and neurodevelopmental disorders. For example, those with intellectual disabilities may also have autism spectrum disorder (ASD) in a comorbid state.

How is autism different from an intellectual disability? Those with ASD can learn new information and can lead lives with supervision. One of the differences in this example is that those with ASD often find it difficult to read emotions and feelings from individuals. Attention deficit disorder is also different in that there is the ability to learn new information, but often there are behaviors such as the subject being very talkative or easily distracted, which leads to problematic labeling and treatment.

Examples of Intellectual Disabilities

The disorders below are actual examples of intellectual disabilities.

22q11.2 Deletion Syndrome (22q11.2.DS)

22q11.2 deletion syndrome (22q11.2 DS) is considered an intellectual disability. It does not have much public awareness compared to other disabilities. A Comprehensive Guide to Intellectual and Developmental Disabilities (Wehmeyer, 2017) explains that this disability manifests in significant intellectual impairment and delays in development, and is a result of a small deletion of DNA on chromosome 22.

Fetal Alcohol Spectrum Disorder (FASD)

Fetal alcohol spectrum disorder (FASD) is one of the most common reasons for the diagnosis of intellectual disabilities. Children who are diagnosed with FASD are known to have many issues including delayed speech and language acquisition and cognition (Wehmeyer, 2017). Children develop FASD when their mother heavily drinks when pregnant.

Fragile X Syndrome (FXS)

Fragile X syndrome (FXS) is the most commonly known inherited type of intellectual disability. This gene mutation affects the x chromosome and is more prevalent in males as compared to females. Children who have this diagnosis have learning delays, hyperactivity, sensitivity to touch and sound, and aggressive outbursts (Wehmeyer, 2017).