Services · Intellectual Disability Assessments
Intellectual Disability Assessments for Children and Adults
An Intellectual Disability assessment looks at much more than an IQ score. It helps us understand how a person learns, reasons and solves problems, as well as how they manage everyday tasks at home, school, work and in the community.
Some families seek an assessment because their child is learning or developing more slowly than expected. Others may notice that their child needs much more help than other children of the same age with things such as learning, communication, safety, self-care, money, routines or making everyday decisions.
Adults may seek an assessment because they have always needed extra support, found learning or independent living difficult, or need a clearer understanding of their strengths and support needs. Some adults reach adulthood without ever having had a formal assessment.
An Intellectual Disability assessment brings these different areas together. It looks at both intellectual functioning and adaptive functioning, as well as the person’s developmental history.
What is Intellectual Disability?
Intellectual Disability, also called Intellectual Developmental Disorder in some diagnostic systems, is a neurodevelopmental condition that begins during the developmental period.
Diagnosis is based on significant difficulties in two broad areas:
- Intellectual functioning – skills involved in learning, reasoning, problem-solving and understanding information.
- Adaptive functioning – the everyday skills a person needs to manage life as independently and safely as possible.
An IQ score by itself is not enough to diagnose Intellectual Disability. We also need to understand how the person manages everyday life and whether these difficulties have been present during development.
What is intellectual or cognitive functioning?
Understanding how a person thinks and learns
Intellectual functioning describes how a person understands information, learns, reasons and solves problems. Psychologists assess this using standardised cognitive or IQ tests, together with other information gathered during the assessment.
Cognitive testing looks at different abilities rather than simply producing one number. Depending on the test used, this may include areas such as verbal reasoning, visual or non-verbal reasoning, working memory and processing speed.
What might difficulties with intellectual functioning look like?
These are examples only. They are not signs that automatically mean someone has an Intellectual Disability.
Children and adolescents
- needing new ideas explained more slowly or in smaller steps
- needing much more repetition before new information is remembered
- finding it difficult to understand abstract ideas or concepts
- learning new skills more slowly than other children of the same age
More examples for children and adolescents
- finding it difficult to work out what to do when a problem is unfamiliar
- struggling to apply something learned in one situation to a different situation
- needing more help to understand cause and effect
- finding multi-step instructions difficult to remember or follow
- becoming overwhelmed when too much information is given at once
- having difficulty understanding time, money or number concepts
- finding schoolwork increasingly difficult as tasks become more complex
- being able to learn a skill with support but needing longer and more practice to use it independently.
Adults
- needing new tasks demonstrated several times
- taking longer to learn new workplace routines
- difficulty understanding complicated written or verbal information
- needing help to break larger problems into smaller steps
More examples for adults
- difficulty planning what to do when something unexpected happens
- finding abstract ideas or hypothetical situations hard to understand
- difficulty comparing options and considering possible consequences
- needing information repeated or presented in a simpler way
- finding forms, contracts, financial information or complex instructions difficult to understand
- being able to complete familiar tasks well but struggling when the situation changes.
What cognitive or IQ tests might be used?
The test used depends on the person’s age, communication, needs and the questions the assessment is trying to answer.
Examples of cognitive assessments we may use include:
- WISC-V – Wechsler Intelligence Scale for Children, commonly used with school-aged children
- WAIS – Wechsler Adult Intelligence Scale, used with adolescents and adults within the relevant age range
- Stanford-Binet Intelligence Scales, Fifth Edition (SB5), which can also be used across a wide age range.
Your psychologist will choose the assessment that is appropriate for the individual. Not every person needs the same test. You can read more about this part of the process on our cognitive assessment page.
What is adaptive functioning?
The skills we use to manage everyday life
Two people can have similar cognitive test scores but manage everyday life very differently. This is one reason an IQ score alone cannot tell us whether someone has an Intellectual Disability or how much support they need.
Adaptive functioning is usually considered across three broad areas: conceptual skills, social skills and practical skills.
What might difficulties with adaptive functioning look like?
Conceptual skills
Conceptual skills include the everyday thinking and communication skills a person uses to understand and manage information. This can include language, reading and writing, number concepts, money, time, planning and self-direction.
Social skills
Social adaptive skills involve understanding other people and managing social situations safely and appropriately. They include communication with others, understanding social expectations, judging people’s intentions, making social decisions and recognising when a situation may be unsafe.
Practical skills
Practical skills are the everyday tasks needed to look after yourself, stay safe and take part in home, school, work and community life.
Children and adolescents
Conceptual skills
- needing significant help to understand homework or school instructions
- difficulty understanding time, such as how long 10 minutes is
- difficulty understanding money or what different amounts are worth
More conceptual examples for children and adolescents
- needing adults to organise belongings, homework or routines well beyond what would be expected for age
- difficulty remembering what needs to happen next
- finding it hard to make simple plans independently
- difficulty using reading, writing or number skills in everyday situations
- needing frequent reminders to complete familiar routines.
Social skills
- finding it difficult to understand social rules that other children seem to learn naturally
- being more socially trusting or naïve than other children of the same age
- difficulty recognising when another child is teasing, manipulating or taking advantage of them
More social examples for children and adolescents
- needing adult help to solve disagreements
- difficulty judging what information is safe to share
- following other children even when the situation may be unsafe
- finding it hard to change their behaviour depending on the social situation
- needing more support than peers to form or maintain friendships.
Practical skills
- needing more help than expected for age with dressing, showering, toileting or personal hygiene
- difficulty preparing simple food or drinks safely
- needing repeated reminders for everyday routines
More practical examples for children and adolescents
- difficulty keeping track of personal belongings
- needing close supervision around roads, cooking or other safety risks
- difficulty using public transport independently when peers of a similar age can
- needing support to remember medication or health routines
- finding changes in routine difficult to manage without help
- needing adults to organise tasks that peers are beginning to manage themselves.
Adults
Conceptual skills
- difficulty reading and understanding letters, bills, forms or instructions
- difficulty managing money or understanding whether something is affordable
- needing help with budgeting or paying bills
More conceptual examples for adults
- difficulty understanding dates, appointments or time
- needing another person to help organise appointments or daily tasks
- difficulty planning several steps ahead
- needing support to understand choices or complicated information
- finding it difficult to independently solve everyday problems.
Social skills
- being unusually trusting of strangers or acquaintances
- difficulty recognising scams, exploitation or unsafe relationships
- taking what another person says at face value
More social examples for adults
- needing help to judge whether someone has good intentions
- difficulty resolving interpersonal problems independently
- finding workplace or community social expectations hard to interpret
- being vulnerable to pressure from others
- needing support to make safe social decisions.
Practical skills
- needing support with shopping, cooking or cleaning
- difficulty using public transport or travelling to unfamiliar places independently
- needing help to manage medication or medical appointments
More practical examples for adults
- difficulty managing money safely
- needing support with personal care or household routines
- difficulty responding appropriately in an emergency
- needing help to plan meals or shop for appropriate groceries
- difficulty keeping appointments or following a daily schedule
- needing support to maintain work routines
- difficulty managing several everyday responsibilities at the same time.
The relevant question is not whether a person can ever do a task. We need to consider how independently, safely, consistently and appropriately they can do it compared with what would normally be expected for their age and environment.
What adaptive functioning tests might be used?
Adaptive functioning is usually assessed using information from people who know the person well and see how they manage everyday life. Depending on the person’s age and circumstances, this may include parents, carers, teachers, partners or support workers.
Examples of adaptive behaviour assessments we may use include:
- Vineland Adaptive Behavior Scales, Third Edition (Vineland-3)
- Adaptive Behavior Assessment System, Third Edition (ABAS-3).
These measures look at everyday functioning across areas such as communication, social skills, self-care, home and community living, safety and independence.
Adaptive functioning measures are not tests that the person needs to “pass”. They help the psychologist understand how everyday skills are currently being used across real-life settings. You can read more on our adaptive functioning assessment page.
Why do we assess both IQ and adaptive functioning?
Both areas are important because Intellectual Disability is not diagnosed from an IQ score alone.
Cognitive testing helps us understand how a person reasons, learns and processes information. Adaptive assessment helps us understand how those skills translate into everyday life.
For example:
One person may find cognitive testing very difficult but have developed strong routines and practical skills that allow them to manage many everyday tasks. Another person with a similar cognitive score may need much more support with communication, safety, money or daily living.
Looking at both areas gives a much more useful picture of the person than a single score.
This is also why severity should not be explained as simply “mild, moderate or severe according to IQ”. How much support a person needs in everyday functioning is central to understanding their presentation, and the report is written to describe what this person needs.
A diagnosis is not just a number
IQ scores can be useful, but no single number describes a whole person.
People may have very different strengths and difficulties across different areas of thinking and everyday life. They may also have strengths in relationships, humour, creativity, practical skills, interests, persistence, routines or other areas that are not captured by an IQ score.
The aim of assessment is to understand the individual person – including what they can do, where they need support and what may help them participate as fully and independently as possible.
What else can affect cognitive or adaptive functioning?
Difficulties with learning or everyday functioning do not automatically mean someone has an Intellectual Disability.
Assessment may also need to consider other factors, including:
- autism
- ADHD
- Specific Learning Disorder, explored through a learning difficulty assessment
- developmental language difficulties
- developmental delays
- neurological or genetic conditions
- acquired brain injury
- hearing or vision difficulties
- physical disability
- mental health difficulties
- educational opportunities
- cultural and language background.
More than one condition can also occur together. For example, a person can have both autism and Intellectual Disability, or ADHD and Intellectual Disability. The assessment therefore considers the broader pattern rather than assuming one difficulty explains everything.
Intellectual Disability and autism
Can someone have both autism and Intellectual Disability?
Yes. Autism and Intellectual Disability can occur together, but they are different diagnoses.
Autism involves differences in social communication and interaction, together with restricted or repetitive behaviours, interests or sensory experiences. Intellectual Disability involves significant difficulties with intellectual functioning and adaptive functioning.
When both are possible, the psychologist considers whether the person’s difficulties are better explained by one condition, whether both are present, and what support the individual needs. You can read more about our Autism assessment process.
What happens during an Intellectual Disability assessment?
1. Initial appointment and assessment plan
Every assessment at The Psychology Hub begins with a 90-minute initial appointment. This appointment is part of the assessment itself.
During this appointment, the psychologist will talk with you about the person’s development, learning, everyday functioning, strengths, difficulties, previous support and the questions you would like the assessment to answer.
We do not assume that everyone needs exactly the same assessment. After the initial appointment, the psychologist will recommend what further assessment is needed and provide a quote for the remaining parts before you decide whether to continue.
2. Questionnaires and adaptive functioning measures
Parents, carers, teachers, partners, support workers or others who know the person well may be asked to provide information about how they manage everyday life. Measures such as the Vineland-3 or ABAS-3 may be used where appropriate.
3. Review of relevant information
With consent, the psychologist may review school reports, previous assessments, medical or allied health reports, support information and other relevant correspondence. For an adult assessment, older school or developmental information can be particularly helpful when it is available.
4. Cognitive testing
The psychologist may complete standardised cognitive testing using a measure such as the WISC-V, WAIS or SB5, depending on the person’s age and individual needs.
Testing is usually completed one-to-one, and breaks can be provided as needed. The psychologist considers the person’s approach to the tasks as well as their scores.
5. Other assessment where needed
Sometimes the initial appointment raises questions about another area, such as autism, ADHD, learning, language or emotional wellbeing. If further assessment would be useful, the psychologist will discuss this with you before anything additional is added.
6. Feedback appointment
Once the information has been brought together, the psychologist will meet with you to explain the results, what they mean and the recommendations.
7. Draft report
A draft report is provided so factual information can be checked and any questions or corrections raised before the report is finalised.
8. Final report
The psychologist then finalises the report, including the findings, conclusions and recommendations relevant to the person’s individual strengths and support needs.
Because the assessment is planned around the individual, the psychologist will recommend the appropriate assessment pathway after the initial appointment. You will receive a quote before the remaining assessment proceeds.
Why does developmental history matter?
Understanding the pattern over time
Intellectual Disability begins during the developmental period. This means the psychologist needs to understand whether the person’s cognitive and everyday functioning difficulties were present while they were developing, rather than appearing for the first time later in adult life.
For children, this information may come from parents, teachers, school records, health or developmental information and previous assessments.
For adults, old school reports, previous assessments or information from family members can be helpful where available. Not having every old record does not automatically mean that an assessment cannot be completed. The psychologist will discuss what information is available and what else may be useful.
What about children under five?
We provide Intellectual Disability assessments from age five.
For children under five, a developmental assessment may still provide important information about their development, strengths and support needs. Global Developmental Delay may be the more appropriate diagnosis at this age when a child’s developmental level cannot yet be assessed reliably enough to determine whether Intellectual Disability is present.
The psychologist can discuss whether further assessment should be considered as the child gets older.
What recommendations might be included?
Recommendations depend on the individual findings and why the assessment was requested.
They may include recommendations relating to:
- support with learning
- communication
- daily routines
- personal care
- money and budgeting
- safety
- travel and community access
- decision-making
- school adjustments
- workplace support
- assistive or visual supports
- building independence gradually
- support from allied health or other professionals
- further assessment where another area needs to be explored.
The goal is not simply to identify what a person finds difficult. Assessment can also help identify existing strengths, the supports that are already working and areas where the right support may increase independence and participation.
If the assessment or report is needed for NDIS, school or another organisation
If an organisation has asked for an Intellectual Disability assessment or report, please tell us before the assessment and send us any requirements you have been given.
This might include the NDIS, a school, university, employer, government agency or another service. Different organisations can have different evidence requirements, so knowing what has been requested helps the psychologist consider this when planning the assessment and report.
Decisions about eligibility for particular funding, adjustments or supports are made by the relevant organisation.
Frequently asked questions
Is an IQ test enough to diagnose Intellectual Disability?
No. An IQ test is only one part of an Intellectual Disability assessment.
Diagnosis also requires significant difficulties with adaptive functioning – the everyday skills a person uses to communicate, make decisions, look after themselves, stay safe and participate in home, school, work and community life. The difficulties must also have begun during the developmental period.
What IQ score means someone has Intellectual Disability?
There is not one IQ score that should be used on its own to decide whether someone has Intellectual Disability.
Cognitive test results are considered alongside adaptive functioning, developmental history, the person’s individual pattern of strengths and difficulties, and other relevant information. Test scores also have a range of measurement error, which is another reason they should not be treated as an exact cut-off by themselves.
How much support a person needs in everyday life is also very important when describing Intellectual Disability.
What is adaptive functioning?
Adaptive functioning is how a person manages the everyday demands of life.
It includes conceptual skills such as communication, money and time; social skills such as understanding people and staying safe in relationships; and practical skills such as self-care, cooking, travel, routines and managing daily responsibilities.
What is a Vineland assessment?
The Vineland Adaptive Behavior Scales, Third Edition (Vineland-3) is an adaptive behaviour assessment. It gathers information about how a person manages everyday skills such as communication, daily living and social functioning.
Depending on the person’s age and circumstances, information may be gathered from a parent, caregiver, teacher or another person who knows them well.
What is an ABAS assessment?
The Adaptive Behavior Assessment System, Third Edition (ABAS-3) is another measure of adaptive functioning. It looks at skills used in everyday life across conceptual, social and practical areas.
The psychologist chooses the measure that best suits the person and the purpose of the assessment.
Can adults be assessed for Intellectual Disability?
Yes. Adults can be assessed even if they were never formally assessed as children.
The psychologist will explore current cognitive and adaptive functioning as well as the person’s developmental history. School reports, previous assessments or information from family members may be useful where available.
Can someone have Intellectual Disability and still have strengths?
Absolutely. Intellectual Disability does not mean that someone has difficulty with everything.
A person may have relative strengths in particular types of thinking, communication, relationships, practical tasks, routines, interests, creativity or other areas. Assessment should identify strengths as well as areas where support is needed.
Can someone have autism and Intellectual Disability?
Yes. Autism and Intellectual Disability can occur together, but they are different diagnoses.
When both are possible, the psychologist considers whether the person’s difficulties are better explained by one condition, whether both are present, and what support the individual needs. This is explained further under Intellectual Disability and autism, and you can read about our Autism assessment process.
Can someone have ADHD and Intellectual Disability?
Yes. ADHD and Intellectual Disability can occur together. Attention and executive functioning difficulties may also affect how someone learns and manages everyday tasks.
Where both are possible, the assessment looks at the broader pattern rather than assuming that one diagnosis explains everything. You can read more about our ADHD assessment process.
How long does an Intellectual Disability assessment take?
The amount of assessment required varies from person to person.
Everyone begins with a 90-minute initial assessment appointment. After that appointment, the psychologist will recommend what further cognitive testing, adaptive functioning measures, questionnaires or information are needed and provide a quote before the remaining assessment continues.
The overall timeframe also depends on appointments, the measures required and how quickly relevant information is returned.
Where and how we offer assessments
Intellectual Disability assessments are available at our North Lakes clinic, north of Brisbane, with some parts of the assessment also available online across Australia where appropriate. Your psychologist will discuss whether cognitive testing needs to be completed in person.
Ready to take the next step?
Whether you are seeking an explanation, planning support, or responding to a request for evidence, we can tell you at the initial appointment exactly what the assessment would involve and what it would cost.
You do not need a referral to book a privately funded assessment. If you are seeking a Medicare rebate, or another organisation has requested the report, please contact us before booking so we can confirm what documentation or referral is required. Book a 90-minute initial appointment, or a free 10–15 minute discovery call if you would like to talk it through first. If you are not sure this is the right assessment, say so when you enquire – working that out is part of what the initial appointment is for.
New to the clinic? See what happens at your first assessment appointment.
