While IQ tests work for a large portion of the population, they are less successful in identifying neurodivergently intelligent people, especially those with disabilities. For example, the commonly used Wechsler IQ tests place a premium on response speed, oral response and fine motor skills. All these are distinct from abstract reasoning and inferential abilities. These requirements may make it difficult to accurately test the intelligence of someone with cerebral palsy, an autism spectrum condition, ADHD, or a similar disability.
There are also a number of subjective considerations in individual testing. If the participant connects poorly with the administrator, this may influence the participant’s performance. Research already suggests that standard IQ tests may underestimate the intelligence of autistic people, especially nonspeaking autistic people. There’s nothing wrong with measuring nonintellective cognitive tasks in order to identify what people’s strengths and weaknesses are. But they should be distinguished from tasks designed to identify a person’s learning and inferential abilities.
The paradox of simplicity
The tasks on standard intelligence tests are relatively simple. Paradoxically, some people who excel at integrating large amounts of discrete information may overthink some of the simpler questions that one encounters on tests. Some tests penalise people for taking too much time to answer questions, which deflates the overall score. In Giftedness 101, Linda Silverman discusses this issue when assessing highly intelligent children using Wechsler tests. These tests force the examiner to end a particular subtest after a participant fails the first set of simpler tasks.
After modifying the criteria so that the participants could complete all the items in the subtest, they were able to handle more complex problems that engaged them more than the simpler questions. Modern-day IQ tests are clinical tests geared toward people of average intelligence. Paradoxes like these may make them less than optimal for the neurodivergently intelligent.
The consequence is that some NI people, especially ones who have a concomitant disability, may not have their intellectual abilities correctly represented by a standard IQ test. They may end up with artificially deflated scores that disqualify them from receiving the support they seek. Using a qualitative model to supplement or replace standard intelligence tests will help detect those who would otherwise go unnoticed.
It’s time for systematic qualitative measures of intelligence
Some diagnosticians who are familiar with the traits of high intelligence do use qualitative assessment. Unfortunately, there is no systematic process by which professionals can look for these traits in routine neuropsychological examinations. Most professionals may have only the vaguest idea of what extreme intelligence looks like. They may use the IQ score as an absolute determiner, while ignoring a respondent’s case history, cultural background, behaviour, and previous test performance.
IQ tests have their uses. But the possibility of their underestimating neurodivergently intelligent people’s abilities should be a clarion call for researchers to develop a qualitative intelligence assessment. This assessment can identify highly intelligent people whose disabilities or backgrounds interfere with traditional testing.
It may help to consider a related practice used for people with intellectual disabilities. When diagnosticians determine whether a person has an intellectual disability, they don’t rely solely on an IQ score. Identifying the educational needs of students who are too intelligent to thrive in standard educational settings must also go beyond the full-scale IQ.
Finally, I think Tony Kushner’s quotation from Angels in America is apropos:
…it should be the questions and shape of a life, its total complexity gathered, arranged, and considered, which matters in the end, not some stamp of salvation or damnation that disperses all the complexity into some unsatisfying little decision…
The context of the play may have been totally different, but the sentiment still fits. Diagnosticians can, and should, use the “shape of people’s lives” to assess someone’s intelligence throughout the lifespan.