The intelligence levels of autistic people, in general, are highly polarized, with many autistic people scoring average to above-average; compared to the general public, more autistic people score in the gifted range (140+ IQ).Misdiagnosis and Dual Diagnoses of Gifted Children and Adults: ADHD, Bipolar, OCD, Asperger’s, Depression, and Other Disorders
Disorder of high intelligence
Research from 2016 by Bernard J. Crespi actually suggests that autism is a “disorder of high intelligence” as a number of recent studies have found a positive genetic correlation between autism genes and measures of mental ability. This research indicates that alleles for autism overlap broadly with alleles for high intelligence. Evidence indicates that autism and high IQ share a diverse set of convergent correlates—specifically:Autism As a Disorder of High Intelligence
- Large brain size.
- Fast brain growth.
- Increased sensory and visual-spatial abilities.
- Enhanced synaptic functions.
- Increased attentional focus.
- High socioeconomic status.
- More deliberative decision-making.
- Profession and occupational interests in engineering and physical sciences.
- High levels of positive assortative mating.
In addition, the research showed that those carrying genetic variants linked to autism had, on average, slightly better test scores than those who did not carry the autism genes. Researchers suggest this is the reason that many autistic people—as well as neurotypicals that have autistic genes—have average to above-average intelligence.Autism IS linked to higher intelligence: People with genes related to the condition ‘scored better in mental ability tests’ | Daily Mail
Autistic people also do better in Raven’s Matrices, a classic intelligence test in which subjects use analytical skills to complete an ongoing visual pattern. According to research by Isabelle Soulières et al. from 2009, autistics were on average:Enhanced visual processing contributes to matrix reasoning in autism (Soulières et al., 2009)
- 40% faster than non-autistics in the Raven’s Standard Progressive Matrices (RSPM) task; and by item type:
- 23% faster than non-autistics on the figural; and
- 42% faster than non-autistics on the analytic items.
A study by Michelle Dawson et al. from 2015 also showed that:The Level and Nature of Autistic Intelligence (Dawson et al., 2015)
- Autistic people scored on average 30%—and in some cases more than 70%—higher on the RSPM than on the WISC-III, an intelligence test for children between the ages of 6 and 16.
- Although a third of the autistic children of the study would be considered in the range of intellectual disability according to the WISC-III, only 5% would be so judged according to the Raven’s Matrices. This also suggests that some of the mainstream intelligence tests don’t fully capture the capabilities of the autistic mind.