TV…no, wait…rain causes autism

A few months ago we looked at a paper that purported to show that watching TV causes autism. Well, that paper has finally been peer reviewed, and therefore published. It’s making the rounds in the media on this historically slow news day.

Monthly Weather Review chief editor Dave Schultz found this article on the BBC web site. Climate-computer guy Dan Hughes found another at the Washington Post.

The original draft paper is here. If you are in one of the ivory towers, you can download the paper here, at the Archives of Pediatrics & Adolescent Medicine.

The idea is that when it rains it drives kids inside to watch television and that watching TV—never mind how—induces autism. The more hours kids spend in front of the boob-tube, the more cases of autism. Since you can’t measure the number of hours of watching TV, you have to do something else. The authors decided that precipitation would be a good proxy. Here are some of the comments from July:

But how can you tell how much TV all these kids watched? You can’t. There is no way to go back to 1970 and count how many hours each baby watched TV. This is a dilemma, because we would really like to test the dose-response. Perhaps there is a proxy? A proxy is a stand-in variable that is so strongly associated with hours of TV watched that it’s almost as good as the real thing. Can you think of any?

How about precipitation? Sure, rain and snow. After all, when it rains, what else is there to do but watch TV? Actually, lots, and when it snows, there’s even more. But, this is the proxy chosen by the researchers (their Figure 6 will hold some interest for those interested in global warming).

They plotted up maps by county for California, Oregon, and Washington, and colored in counties that had more than median precipitation (from 1990-2001) and then colored those with higher than median autism rates. These colored squares tended to be in the same spot, and is what led them to the conclusion that watching TV causes autism. Case closed.

Mark Lever, chief executive of The National Autistic Society, is properly sanguine about the research. He said, “the latest theory would join a succession of others advanced about the condition and its origins.”

In recent years autism has been linked to factors as varied as older aged fathers, early television viewing, vaccines, food allergies, heavy metal poisoning, and wireless technology, to name just a few.

Some of these theories are little more than conjecture or have been discredited, others seem more promising and are in need of further study. As yet, however, very few have been substantiated by scientific research.

We don’t yet understand what causes autism, although scientists do believe that genetic factors might play a part.

People with autism and their families are naturally concerned to get the right information and there is a lot of confusion and concern over the conflicting theories put forward.

Another guy named Weiss “thinks the results of the study need to be taken with a grain of salt.” To counter that, a man called Lathe said, “Emissions from manufacturing industries, power plants, and from domestic waste incineration generally rise to the troposphere to be diluted into the large volume of the atmosphere. Precipitation can dump this load back on the land, to be absorbed by plants and animals in the food chain.” Not very good meteorology there, because we could equally say that lack of precipitation allows the atmospheric pollution to be worse, causing increases in inhaled ozone, etc. etc.

Overall, there doesn’t seem to be a solid link between rain or TV and autism. The authors of the paper even say “that families more prone to having autistic children may reside in areas with high levels of precipitation, or that such areas might use broader diagnostic criteria for diagnosing autism.” There does seem to have been an increase in the rates of autism, but that increase could very easily be from increased awareness and subsequent diagnoses of the disease.

Nothing has changed between the draft work and the peer-reviewed one to cause me to change my mind about the value of the paper. What I didn’t know before, but I learned from the Post today, is that the lead author and economist Waldman has a son who is autistic. I can therefore understand what motivates him and the desire to find out what happened.

12 Comments

  1. Ari

    Dr. Buzz0 over at The Depleted Cranium has this interesting graph up that shows that as prevalence of “mental retardation” drops, “autism” rises. Almost in lock-step.

    http://depletedcranium.com/autism_and_mr_cht.jpg

    Now, I know it may mean nothing, but it’s interesting nonetheless.

  2. Ari:

    That doesn’t seem like a very scientific conclusion. Unless I totally missed the point of what Briggs is trying to tell us, wouldn’t a better theory be that watching TV…err…rain prevents mental retardation?

  3. Ari

    Matt,

    I think the point of that graph is to argue that our diagnoses are changing more than the prevalence of autism is increasing. What was once placed in a broader spectrum of “mental retardation” is now being put into more specific categories, like autism, Asperger’s, etc.

    Essentially, we’re moving away from saying any kid with a mental/learning disability is just retarded to actually having a sort of spectrum of illnesses. I think that’s the point.

    Sorry, I should have been clearer.

  4. Ari:

    Sorry, I should have added the [sarcasm] tags. 🙂

  5. Mr Evilwrench

    I tend to think that autism is primarily genetic in origin, though perhaps with other aggravating factors. The thing is, our society is very protective of the marginal, fostering their survival where the autistic or retarded would quickly have been selected out of the gene pool by sabre-toothed tigers and other hazards in earlier days. As a result, maladaptive variations are allowed to flourish, resulting in a weakening genetic stock overall. It’s a dilemma.

  6. Pompous Git

    I haven’t read the paper referred to, but I have read quite a lot about High Functioning Autism (Asperger Syndrome). My conclusion is that it’s in large part genetic. I’m an Aspie, my sons are Aspies and my father was an Aspie. My father grew up on a farm in Austria. I grew up in UKLand. My older son grew up in Sydney with his mother. My younger son grew up with me and his mother on a farm in southern Tasmania. Widely differing environments.

    Oh yes. We are all in the top 5% of the population for IQ, so forget the retarded bit. And I suspect that it was this that gave an evolutionary advantage in our ancestry.

  7. James S

    High levels of rain could equally cause less interaction between children of the same age as parents are less willing to go off to coffee shops / community centres to meet up with other parents.

    When the kids are older they may spend less time playing with friends if it is constantly raining.

    So there COULD be a correlation between rainfall and autism which has nothing to do with television watching.

    Although there are big problems with this sort of research which makes any conclusions almost impossible to support. For example if you live somewhere with above average rainfall you may be more used / prepared for it and so it won’t change your behaviour. There could be other weather effects which work against the increased rainfall effects (for example when we lived in London, UK we barely left the house with the kids due to the rubbish weather and constant rain – upon moving to Auckland, NZ the kids spend most of their days out of the house even though there is far more rain in Auckland than London … the difference is that the rain comes down all at once in Auckland and there is much more sun here as well).

  8. masmit

    Mr Evilwrench, it’d be interesting to know just how many people afflicted with these ‘maladaptive variations’ get to reproduce…

  9. masmit

    Mr Evilwrench, how many of those afflicted with these ‘maladaptive variations’ get to reproduce?

  10. masmit

    If, at first you don’t (appear to) succeed…. 🙂

  11. Was going to suggest the causative factor might be an excessive accumulation of feather dust on cooped up raptors who, once a storm abates, scatter out searching prey and thus overly contaminate the freshly rinsed atmosphere at the same moment children pent up with boredom pour forth outdoors to play. But I decided against suggesting this point when I read Brigg’s last paragraph.

    Waldman’s “desire to know what happened” therein is a sad clue to the motivation for these enquiries. The universal idea lurking unspoken is once a cause is known, a cure might be soon forthcoming. Alas, the current state of the world’s care “industry” tells me it is more likely fixes, if any, will be ignored on the basis they are “too intrusive”. But hope springs eternal.

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