Autism & Intelligence: Might Disability and Genius Have More in Common than Meets the Eye?

We’re all familiar with the caricature of the stereotypical nerd: male, glasses, nasally monotonic voice, pedantic, obscure sense of humor, highly intelligent, calculators spilling from every pocket, and woefully socially inept. Our concept couldn’t have been summarized better than in the ’80s movie, Revenge of the Nerds.

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Interestingly, these same stereotypes share much in common with stereotypes our society has of high-functioning autistic males. As early as Leo Kanner’s original publication, there have been links between autism and high IQ. Though there’s debate about selection bias, Kanner noticed that the parents of his autistic patients were often intelligent and highly educated.

Do autism and high intelligence share common features? For one, Bernier et al. (2012) found that parents of autistic children from multiplex families, in contrast to simplex families, were more likely to exhibit subtle autistic features themselves. Baron-Cohen also reported that autism occurred more in families of physicists, engineers, and mathematicians, a finding which he has tied to his Extreme Male Brain Theory of Autism. There’s been much work over the last decade that suggests that there are distinctive patterns to genetic inheritance in multiplex vs. simplex families. It is has been reported that simplex cases may be overrepresented by more severely disabling de novo (new) mutations unseen in the parents; meanwhile, multiplex genetic inheritance likely represents milder– and possibly also polygenic– forms, allowing them to be passed down over multiple generations with less disruption.

A new study by Clarke et al. (2015) reports that higher intelligence in the general population is strongly correlated with inheritance of genetic risk factors for autism, reinforcing the concept that autism and human intelligence share some common roots. At the same time, the researchers found that genetic risk factors for ADHD did not show significant links with intelligence.

It has been fairly well accepted that giftedness is overrepresented in the autistic population, though it’s been poorly researched beyond anything qualitative. Savantism has been noted in individuals from all ranges of functioning and many high-functioning autistics may also fall under the umbrella of Twice Exceptional (2e). It has also become the fad to posthumously diagnose famous or even fictional individuals with Asperger’s Syndrome. For instance, in Dr. Michael Fitzgerald’s book, The Genesis of Artistic Creativity, he reviews what he identifies as autistic-like traits of famous writers, philosophers, musicians, and painters such as William Butler Yeats, Immanuel Kant, Mozart, and Andy Warhol.

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Why have we become so entranced by the idea that with great ability can often come disability? Perhaps it’s our fondness of romanticized notions, or expecting the unexpected. Who, after all, wouldn’t be shocked to find that a severely disabled blind autistic man was an incredible musical savant? On the flip side, our fascination with ability in disability may cause us to underestimate the difficulties that people with autism may have. Many parents of severely affected children, for instance, feel that our society’s focus on the positives of autism, particularly those more often associated with high functioning forms, detracts from public awareness and help for those who will likely never lead independent lives. On the flip side, why would we not want to celebrate a person’s ability in the face of harsh challenges? Thus, we would wish neither to over-paint a rosey picture nor demonize a person’s condition but find a middle ground in our perception of this extraordinarily diverse group of conditions.

The idea that a single group of complex conditions can span the gambit from intellectual disability to genius is a scientifically fascinating idea and suggests that at least some forms of ability and disability have more in common than meets the eye. I for one would love to know whether evolution of the human intellect has led to an increased risk for developing conditions like autism, which may help to explain their frequency. And the recent publication by Bernier et al. would suggest that may well be the case.

6 responses to “Autism & Intelligence: Might Disability and Genius Have More in Common than Meets the Eye?

  1. Autistic-like traits or the broad autism phenotype (BAP) has been studied for decades Genetically influenced BAP traits are common, heritable and widely distributed throughout the general population. There are differences between affected and unaffected family members who share BAP traits. Structural anomolies of the brain are seen more frequently in ASD than in their unaffected clinically normal family members with BAP traits. The question is if familial BAP features are causitive or simply a background genetic effect that in ASD, when combined with structual anomolies in the brain, that disriguishes ASD from non ASD with BAP traits being manifested at the extremes in ASD. In Down Syndrome with ASD familial BAP distinguishes Down Syndrome plus ASD from Down Syndrome with no ASD whose family members are not BAP postive.

    http://www.ncbi.nlm.nih.gov/pubmed/11079353

    In fact, the ‘missing heritabilty’ in ASD may not be ASD at all, but rather the BAP traits that cluster within families in both affected and unaffected family members.

    • Very interesting. I wasn’t aware of the BAP vs. no-BAP in Down’s and its relation to ASD comorbidity. I also wonder whether, in multiplex families, we’re dealing with more polygenic conditions. With ASD vs. BAP siblings, perhaps the genetic load is heavier in the former. Have you read anything in these regards, Robert?

  2. The data is mixed. Piven found a higher rate where both parents were BAP positive in muliplex families but others did not.

    http://www.ncbi.nlm.nih.gov/pubmed/21949002

    Interestingly the pre-mutation mothers of children diagnosed with Fragile X who did not have Fragile X themselves showed a high rate of BAP positive traits, the study did not correlate.the presence of materanl BAP scores with Fragile X plus autism.

    http://www.ncbi.nlm.nih.gov/pubmed/22693142

    The studies throughout the literature shows that in ASD, parents and siblings show increased rates of BAP positive traits… But what is not discussed is the family members are unaffected as would be expected in any multifactorial medical condition. The line between BAP positiveand BAP negative are ambigous and cutoffs are arbitrary.

    The questionnaires that score BAP traits examine personality and social communicaton traits only.

    http://www.ncbi.nlm.nih.gov/pubmed/23171198

    • I’d prefer BAP testing to involve a lot more investigation of repetitive features, e.g., obsessive-compulsiveness. Plus sensory issues, anxiety, etc. From the higher-functioning individuals I’m familiar with, especially females, deficits in the social domain seem much subtler and problem issues surround sensory and repetitive domains.

  3. An idea posited by Richard Deth is that the autistic brain is essentially always turned on, due to oxidative stress. The brain’s redox balance is abnormally shifted toward oxidation, and its many redox-dependent enzymes are switched on. Thus high intelligence might be a hyperactivity of the brain.

    • Yes, Richard is very focused on redox in autism. I don’t necessarily disagree, since with any kind of cellular stress the cell invariably responds with redox and inflammatory pathways in order to mitigate regrowth and repair. But that also becomes a case of chicken and egg, in that overexcitation should lead to increased production of redox metabolites and inflammatory markers, but then chronic production could also promote hyperexcitability. Thus, are we dealing with a normal cycle gone chronically awry? Hard to say.

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