This hypothesis is of course very speculative, and it would be impossible to test it in the short term. At best, it might be possible to carry out genetic studies of certain populations that have been isolated for a long time, such as the Amish.
What I want to do in this post is explore a number of genetic mini-epidemic theories. Note that these theories had been proposed to try to explain the explosion of autism diagnoses that started in the early 1990s. At this point we know the most likely explanation for the 'autism epidemic' is that of 'broadening criteria/awareness' – based on the changing characteristics of the autistic population and regional peculiarities. Nevertheless, these genetic theories do propose mechanisms by which the frequency of alleles might change in human populations over long periods of time, which could have intriguing implications on human evolutionary theory.
The Geek Syndrome Theory
This theory is often attributed to an article from Wired Magazine titled The Geek Syndrome (2001).
What the Geek Syndrome Theory proposes is that the success of the computer industry has helped geek types get better employment, marry and procreate in higher proportion than would have been possible in the past.
In another age, these men would have been monks, developing new ink for printing presses. Suddenly, they're reproducing at a much higher rate.
The article claims that autism "is surging among the children of Silicon Valley." It further notes that "the picture in California is particularly bleak in Santa Clara County." This specifically refers to the caseload of the San Andreas Regional Center. The statement is rather inaccurate (plus you might guess what I think about the "bleak" wording). The ratio to epilepsy in that Regional Center was 0.53 in December 2002. The same ratio in the Westside Regional Center was 1.19. As we know, the bulk of the 'epidemic' occurred in the Los Angeles area. Unfortunately, it is difficult to determine if San Andreas was slightly different to other parts of California, because of inequivalence.
There is some plausibility for this theory despite lack of supporting data. This is because a relatively high proportion of engineers and scientists can be found in the families of autistics [ref][ref]. Also, have you seen the video of Bill Gates rocking autistically?
The Assortative Mating Theory
I'm intrigued by the assortative mating theory because my father-in-law appears to be quite the Aspie, although undiagnosed. In a different time perhaps my wife and I would not have met. Today people are very mobile and are able to meet a variety of different potential partners.
This theory is proposed by Simon Baron-Cohen [ref], and it connects with his extreme male brain theory which proposes that males are good at systemizing. Baron-Cohen suggests that two parents who are systemizers might have a greater probability of having an autistic child. He further proposes that it has become easier for geeky types to meet each other because of better job opportunities, and more women working in technical fields.
Again, this theory is plausible but it counts with no supporting prevalence data.
The Genetic Drift Theory
This theory is not formally proposed anywhere that I could find but it is straight forward. In evolution theory the best known mechanism of change is natural selection. But there is another mechanism, called genetic drift. Basically what this means is that the frequency of alleles is not reproduced exactly from one generation to the next, even absent any selection pressures. In particular, if a liability suddenly becomes less of a liability, it has a greater chance of being passed down. A good example of this phenomenon is the evolution of blindness and albinism in cave-dwelling fish [ref].
In the past, autistics with immune system dysfunctions might have had reduced odds of survival. Similarly, a future where most human interaction will be carried out online might not require advanced speech or social skills.
There is some evidence that the human brain is still evolving and becoming bigger as time goes by [ref]. This could also be an effect of genetic drift. Note that a bigger brain is not necessarily free of liabilities. It implies that humans will require longer to develop. Neanderthals, who had 13% bigger brain capacity, did not have speech as advanced as that of Homo Sapiens.
None of these theories have any predictive relevance if pre-natal testing for autism becomes available in the near future as part of eugenics program aimed at eliminating the autism phenotype. If this comes to pass, it will likely not be without a fight. I also believe that such an event will not only be genocidal, but at the same time suicidal for the human race to carry out.
- Would You Have Allowed Bill Gates to be Born?
- Apology From an Autism Researcher.
- The Assortative Mating Theory: A Talk With Simon Baron-Cohen.
- The Autistic Genocide Clock.
- The Disability Rights Critique of Prenatal Genetic Testing.
- Genetic Studies of Autism: From the 1970s into the Millennium.
- Increase in Autism Caused by Modern Breeding Habits?
- The Neanderthal Theory of Autism.
- Scientific Brain Linked to Autism.
- Heritability of Autism.
- The Geek Syndrome.
- Autism Prenatal Testing