Another study by the Simon Baron-Cohen research group has been getting some media attention today. I read this media report this morning. Curiosity piqued, I tried to find the primary source for this, but unfortunately it had been behind a pay wall. In the comments section of my previous post, a reader asked me for my take on the study and stated that he/she was able to download it for free. I gave them my take from what I had read in the media reports before reading the actual study. I was wondering if it were still behind the paywall. Skeptical, I tried again, and sure enough, I was able to download the entire study and read it. My comment was short and I feel the study deserves a post all its own.
Baron-Cohen in the past has made the bold statements and strong hypothesis that autism genes are responsible for so-called systemetizers and this is why autism has stayed in the general population in spite of the fact that autistics seldom have children. He seems to have gone further and intimated that my suffering may be necessary to society. I have taken him to task for this elsewhere.
Martine Roelfesema and Simon Baron-Cohen and a few other authors have recently published a study in JADD, suggesting that autism may be much more prevalent in areas of the Netherlands where a concentration of IT companies such as Philips and IBM are based. They surveyed three different metropolitan areas of Holland and found prevalence rates 3-4 times as high in the area with high tech companies than in the other two cities. They suggested that genes responsible for systematization may be responsible for this.
Superficially, this study is interesting and makes good fodder for journalists looking for an intriguing story about autism and its alleged gifts. However, on closer analysis and reading, it would appear the study has some limitations and possible flaws.
While the CDC in the American prevalence studies have found great differences in prevalence in various parts of the country, it would appear that Arizona which has one of the highest prevalence rates does not have industries that would employ so-called systemetizers. I don't know whether this is true in New Jersey or not.
There are also great variations in prevalences in various parts of California according to past CDDS data. Though the Silicone Valley has higher rates than rural parts of California it is substantially lower than in Los Angeles, which would refute Baron-Cohen and company's notion about there being a casual relationship between technology abilities in parents and autistic offspring.
Variations in prevalence in Holland would be far less likely due to differences in income, population density, socioeconomic status as the country is far more homogeneous in its population than the U.S.
Recruitment in the study was voluntary. Only a bit more than half the schools who were asked to survey consented. The response rate was substantially higher for the high prevalence group than the other two areas. Weighting factors that I concede I don't understand were used to supposedly eliminate this bias, but I'm still skeptical. The response rates from special ed schools was much higher than mainstream schools. The age range of kids surveyed was 4-16. In one of the two control communities, the prevalence rate was about the same in the older kids than in the younger kids. In the other two communities it was much higher as later diagnosis was included. This could have influenced the results of the study. The diagnoses were not verified, though this may have been infeasible.
Most germane of all, the Baron-Cohen group did not control for persons moving into the high prevalence area because of the possibility of better services, etc. so this might invalidate the findings. There may be other issues in the study that I will think of and I might go in and edit this post later if I can think of them.
This stuff also interests me, because, as regular readers of my blog know, my father was a pioneer in the computer industry, and I wondered if his genes somehow caused my autism. However, there seems to be a more pertinent history from my mother's family than from my father's, as I had a very depressed maternal grandmother and her brother (my great uncle) was likely to have been an undiagnosed autistic in the very early 1900s. Though neither my sister nor any of my first cousins on my mother's side have autism, there seems to be a high rate of dyslexia and ADHD amongst them, which would be far higher than the occurrence of chance.
Baron-Cohen has also stated (though I can't recall exactly where) that it is possible that males who were good systematizers might have been unable to find a mate at one time and with the advent of the IT revolution and silicone valley this might no longer be a problem and two engineers and programmers would be likely to marry and produce an autistic offspring. This does not jive with the personal experience of my father and the men whom he worked with going back to the early 1950s, before a big computer revolution and increase in autism prevalence. My dad and I'm pretty sure all of these systemetizers he worked with were able to marry and produce children. I'm pretty sure none of their wives were engineers or worked in the IT profession (this includes my mom of course) and with the exception of one individual from England who had a daughter who was either severely retarded or autistic, I don't think any of the other engineers and computer people dad worked with had children that were on the autistic spectrum.
The currently published study is only phase I. They state that phase II of the study which will in part address some of the issues I have discussed in this post are forthcoming. I will await it.