One of the reasons, why IQ tests are flawed is that it can underestimate or overestimate the abilities and challenges that autistic people actually have. In fact, IQ is the biggest determinant when considering if a person is "high functioning" or "low functioning." There are two scenarios in which this can occur. For people whose autism is not as apparent and have the privilege of passing, our high scores on intelligence tests can prevent us from getting the support we need. There is this erroneous and outdated assumption that if an autistic person has high intelligence then they can navigate neurotypical society with little to no support. In fact, some states will deny support services to those who score above 70 on IQ tests. However as this article states, intelligence tests don't account the executive functioning challenges that autistic people without intellectual disabilities face in their day-to-day lives. For instance a person who tests in the "average to above-average" range on IQ tests may have difficulty to do important tasks of daily living such as grocery shopping, budgeting, personal hygiene etc.
I am one of those on the spectrum that would score high on traditional intelligence tests, but I still find some crucial activities of daily living such as cooking, making doctor's appointments, transportation etc. very challenging and still require support to navigate some of these tasks. My so-called "high IQ" masks some of the social challenges (e.g. social anxiety) I still face as an adult on the spectrum. Eventually when I plan to live on my own, I will require support to effectively manage the transition of living away from parents as well as managing activities of daily living. However, I am afraid that my "high IQ score" would serve as a barrier for people to recognize my support needs.
For the other scenario, having a "low IQ" can make people underestimate the abilities of some autistic people especially for those who have limited to no speech. Autistic individuals without any reliable spoken language tend to score low on traditional intelligence tests which makes the people around them doubt that they have any capabilities. For instance, their parents would have been told by many doctors and experts that they would more likely end up in an "institution" and less likely to be mainstreamed and pursue postsecondary education. They would also more likely be relegated to segregated classroom settings. However there is a growing group of nonspeaking autistics that have shown that "being nonverbal does not mean not thinking." In fact, some went on to pursue postsecondary education as illustrated in the lifestories of DJ Savarese and Sue Rubin. These examples show how faulty the results of traditional IQ tests can be for those who are more affected by autism. Consequently, it can lead people to mistakenly believe that they are "intellectually disabled."
Another big reason why intelligence tests are inaccurate measures, is that autistic people usually don't test well. These tests require a person to sit in a room for a long period of time and have questions that contain a lot of verbal information. The testing environment may also trigger sensory issues in some autistic individuals. Some also don't have the attention span and cooperation to do the tasks the test examiner wants them to complete . When I first got diagnosed, I took a verbal IQ test in which I did terribly on due to my limited language capacities. The examiner who was a young graduate student mistakenly thought that I had an intellectual disability based of my test results. When my mother talked with the head psychologist, she said I was given the wrong test. This shows how the structure of the tests themselves can not accurately predict the true intelligence levels of autistic people.
Lastly, people on the autistic spectrum demonstrate their intelligence in different ways than what is reflected on traditional IQ tests like the Wechslers or Stanford-Binet scale. For instance, this article talks about how these IQ tests set autistic people up to fail by overlooking their hidden talents by emphasizing their disability. For instance, two boys that I work with (I am a paraprofessional at a special needs school) demonstrate the discrepancy between IQ score and actual intelligence. One has a short attention span and gets easily overwhelmed with a lot of verbal information which would make testing his IQ very hard. However he has knows roman numerals, can write the alphabet backwards and can script in different foreign languages. The other boy also has a hard time with paying attention and would have a hard time completing the tasks and following the verbal instructions that characterize most IQ tests. However, he is really good at computers (he has his own youtube channel), knows the different models of trains and cars and memorizes license plate numbers and phone numbers. These boys would not test well when given traditional intelligence tests, but it is evident that they have hidden talents that are not easily seen.
These are some of the ways how intelligence tests can fall short of describing the actual abilities and challenges that autistic people have. Autistic people often have "spiky profiles" meaning that they will have strengths in some areas while they struggle in other areas. We need to stop conflating autism with intellectual disability. This means state supports (especially the adult service system) need to cater more to the needs of autistic individuals. Therefore, eligibility criteria to qualify for such services needs to changed to reflect the unique and ever changing needs of those on the spectrum. Other methods need to be explored in terms of measuring the actual intelligence of an individual with autism besides relying on the Wechsler scale. We need to look at the whole person on the spectrum and then determine the appropriate supports rather than just making assumptions based on a single IQ score.
