Autism and TV Watching
There’s been yet another attempt to try and find out what it is that might be causing the rise in autism. Gregg Easterbrook writes about it in Slate and I have to say that it’s really not all that great a piece of work.
The basic thought is that children’s minds need continual stimulation: OK, we agree there, but then there are thoughts that they need to get this from 3D imagery, not 2 D. Well, if that is so, why aren’t all blind people autistic then?
The researchers did indeed find a correlation (and remember, correlation is not causation) between the arrival of cable television in an area and a rise in autism. They also found one between more rainfall in an area and more autism: maybe, they think, more rain means more TV watching?
The problem with this is that from Simon Baron-Cohen’s work, (he of our EQSQ personality tests) we think that autism is actually triggered by an excess of fetal exposure to testosterone. The trigger for that we think is genetic, where two highly systemizing people (or rather the genes for that), again as measured by the EQSQ personality tests, have children. As more people of like type (as a result of women’s move into the labor force) are marrying each other, thus we see the rise in autism.
Two economists who know a great deal about the math used in the original study are sceptical: Tyler Cowen and Steven Levitt (yes, of Freakonomics). Comments 4 and 9 there are especially good.
October 20th, 2006 at 1:19 am
Tim, the argument for 3-dimensional opposed to 2-dimensional has much more to do with the hazards of, as Easterbrook says, “exposing toddlers to lots of colorful two-dimensional stimulation” that “could be harmful to brain development.” It’s not assumed that those who can experience neither would be harmed. But regular exposure to this loud and gawdy 2-D world can change the perception and possibly make-up of young minds. Obviously, those who are blind use their other senses to capture the world, and therefore most often have enhanced senses of smell, feel, hearing, and taste. And are not affected by this 2-D overkill.
Also the study discussed in the article is not Slates’, but Cornell University’s:
http://www.johnson.cornell.edu/faculty/profiles/waldman/autpaper.html.
If we’re going to contrast Cornell’s findings with Baron-Cohen’s, a better approach probably would be to first see if there are any correlations. For instance, as Cornell has found strong evidence linking cable t.v. watching and autism and Baron-Cohen has found strong evidence between excess fetal exposure to autism to testosterone and autism, a good question might be: “Couldn’t autistic children simply watch more television than non-autistic children?” As autistic children have impaired social interaction, impaired communication, are prone to aggressive behavior, tantrums, short attention spans, and mood swings, maybe parents would be more likely to turn to television for some relief.
October 20th, 2006 at 9:30 pm
Lucy, as ever, your intelligence shines through. That idea that autism causes TV watching, not the other way around is indeed interesting. Did you note that in the Marginal Revolution discussion of the Cornell paper Tyler pointed to the fact that precipitation was a better guide than the presence of cable TV to autism incidence? The more rain and snow there is the more children will be inside: thus the more parents will be directly interacting with the children rather than the little tykes be playing outside. Those who don’t, as autistics do not, interact well could indeed be watching more TV.
I have to admit though that with this specific idea about the causes of autism I was extremely impressed with the piece of intelligence we got in the comments at Freakonomics. The diagnosis of autism, the extention of it along the spectrum (Asperger’s and so on) actually happened in 1980: just at the time that cable TV rolled out across the land.
It really could be, as far as that Cornell paper is concerned, simply be correlation, not causation of any kind.
October 20th, 2006 at 11:57 pm
Lucy’s point that correlations work in both directions is important to keep in mind. Autistic children probably do watch more TV. But why would the incidence of autism be higher in areas with precipitation? Sure, autistic children might watch more TV in those areas. But the overall incidence of autism shouldn’t be any higher than in other areas of the county, if TV is playing no role.
I see the two arguments working out like this:
Cornell Study:
Precipitation=TV watching
TV watching=Autism
RESULT: More autistic children in high precipitation area
Reversal of Correlation:
High precipitation area=children inside
Autistic child inside=more likely to be plunked in front of TV
RESULT: Autistic children watching more TV than usual and more than other children.
NOT: More autistic children in area
I can see how TV watching among autistic children would be higher in areas where precipitation rates are higher. But that doesn’t explain the increase of diagnoses in the region. Right?
October 27th, 2006 at 4:26 am
Good point, Millie. I understand that when studying Cornell’s findings, the correlation must go both ways when coming to some conclusion. I simply have a hard time buying that television watching, in and of itself, causes autism. I am not a television watcher myself; I allow my children very little television time; and, as an educator, I would be thrilled to see children spend less time in front of the television. Still, I have a strong sense there’s something more behind this.
I’ve looked over the Cornell paper, especially at the figures at the end. I wonder, when the writers included maps revealing states’ rate of precipitation in relation to its rate of autism, why they did not include maps revealing the states’ rate of cable television subscriptions.
And of course, the following needs to be addressed before any conclusive evidence can be revealed: are certain areas in the country (and in states) identifying autism at higher rates than others (because of household income, whether there is health insurance, etc.); might something else about spending more time indoors than outdoors triggering autism (lead levels in homes, lack of exercise, cigarette smoke, etc); and do autistic children simply watch more tv?
October 27th, 2006 at 8:35 pm
One of the things I love about this here internet thing is the way in which the distributed intelligence comes into play. Perhaps the collective intelligence is a better phrase. On another blog this past week I’ve heard the point, hey, maybe mold causes autism? More precipitation, more mold and also more TV watching?
No, I don’t buy it either, it’s just an example of causation not having been proven.
I’ll admit to being slightly conflicted here. TV as a cause just sounds wrong to me (as do the other recent ideas, older mothers, older fathers to name just two from this week) but I’m not really sufficiently a professional in the field to be able to prove why. Does that make sense?
I think there’s an awfully large number of people chasing various correlations but few if any (other than assortive mating and fetal testosterone) seem to offer a reasonable route for causation.