What is Intellectual Disability?

In 2012 the Australian Bureau of Statistics reported that approximately 2.9% of the population had a diagnosed Intellectual Disability.

In first discussing Intellectual Disability (ID) it is important to know that children, teenagers and adults can and do learn new skills. ID is however referred to as having a below average intelligence quotient (IQ) that affects the individuals’ ability to manage day to day activities with an onset before 18 years of age.

What is Intellectual Disability?

The Diagnostic Statistical Manual (DSM5) has reviewed how this disability is now referred to and focused on three domains or areas that affect an individual’s functioning. ‘So what is intellectual disability?’ It is a disorder that affects an individual in three areas or domains of adaptive function. Adaptive function is how an individual copes with the everyday demands of-

  • Conceptual tasks- skills in language, reading, writing, math, reasoning, knowledge, and memory.
  • Social ability- refers to empathy, social judgment, interpersonal communication skills, the ability to make and retain friendships, and similar capacities.
  • Practical skills- centres on self-management in areas such as personal care, job responsibilities, money management, recreation, and organizing school and work tasks.

What is Intellectual Disability and are there types of intellectual disability? Intellectual Disability is an IQ that is assessed at below 70 which has a limiting effect on a person’s’ capacity to function in comparison to their same age peers.


Types of Intellectual Disability

The most common types of intellectual disability can be associated with other disorders such as autism spectrum disorder, Down Syndrome, Fragile X syndrome and Fetal Alcohol Spectrum Disorder(FASD).

These types of intellectual disabilities can be further explained by the severity of intellectual functioning as tested using a formal diagnostic tool that obtains an Intelligence Quotient(IQ):-

There are types of intellectual disability as identified in the Diagnostic Statistical Manual 5(DSM 5).  Severity of disability is identified as follows:

Mild: IQ level 70  to approximately 50-55

Moderate: IQ level  50-55 to 35-40

Severe: IQ level  35-40 to 20-25

Profound: IQ level below 20-25

As identified the more common types of intellectual disability can be as a result of genetic conditions such as Down syndrome and Fragile X syndrome. If a woman consumes alcohol during pregnancy, there is a risk of having a child with FASD which may result in the child having an intellectual disability. Other difficulties or exposure to toxins such as lead or mercury during pregnancy have been linked to intellectual disability. Contact with measles, meningitis or whooping cough can also place a child at risk.

The impact of the various types of intellectual disability can vary. All children develop at different rates and this will be the same for those with an intellectual disability. School will pose challenges for these children but all children can learn and will learn at their pace given the opportunities and exposure to experiences alongside their peers.

Boys aged 0-14 years are twice as likely to have intellectual disability than girls in the same age group. This is possibly due to the fact that boys have higher rates of some conditions that are more commonly associated with intellectual disability. For example, boys in this age group were 3.6 times more likely to have Autism Spectrum Disorder  or a related disorder than girls, 50,500 boys compared with 13,900 girls.

A person with ID has limitations within at least two areas of their daily functioning. These are:

  • Capacity for intellectual functioning, referred to as IQ, which indicates the level at which a person can learn, reason, make decisions and solve problems on a daily basis.
  • Adaptive behaviour which refers to the ability to function daily for such things as self-care, communication and the ability to have interactions with other people.

The severity of the disability may be obvious early in infancy or if it is mild it may in fact not be identified until a young child commences school. Some of the signs to be aware of are:

  • The young child may be late to roll over, sit up, crawl or walk
  • They may have trouble talking or be late to talk
  • They may not appear to understand what others are saying
  • Simple skills such as getting dressed, feeding themselves and being toilet trained may not be achieved
  • They may have trouble interacting with children of the same age
  • They may show difficulty in remembering things and problem solving
  • They may not demonstrate an understanding of the consequences of their actions and could be prone to more childhood tantrums than is typical

Intellectual disability can present very differently for many children, teenagers and adults. There are however a range of interventions and supports to assist learning and each individual’s capacity to manage the functions of daily life. Within this website you will be assisted to navigate this journey with your child.