07 January 2008

What would it take? (Or, Why the debate will never end)

Before you read the rest of this post, please take a moment (or, if you read as slow as I do, several moments) to read these two posts, by different authors, discussing the study Continuing Increases in Autism Reported to California’s Developmental Services System: Mercury in Retrograde and the accompanying essay Thimerosal Disappears but Autism Remains published in this month's Archives of General Psychiatry:

So, what do you think? Does the study prove anything? Disprove anything? If you believed before reading these posts that autism is caused primarily by thimerosal (or mercury in general), did reading these posts change your mind, or cause you to doubt that position? Conversely, if you believed before reading these posts that thimerosal / mercury is not a cause of autism, did reading these posts cause you to change your mind, or to question your beliefs?

On the Autism Blog at About.com, Lisa Jo Rudy hits the nail right on the head with this pessimistic (but unfortunately accurate) observation:
Knowing the autism community as I do, I find it hard to believe that these findings will change much of anything. Those who believe firmly that vaccines are NOT to blame for the rise in autism diagnoses will stand on these findings as proof positive of their claims. Meanwhile, those who believe firmly in the toxic nature of vaccines will continue to advocate for an end to required vaccinations - and for compensation for vaccine damage to their children.
In his article on Age of Autism, Mark Blaxill effectively quotes Karl Popper as a guide in his examination and acceptance of criticism to his theory:
He who gives up his theory too easily in the face of apparent refutations will never discover the possibilities inherent in his theory. There is room in science for debate: for attack and therefore also for defense...But do not give up your theories too easily--not, at any rate before you have critically examined your criticism.
But this then begs the question, at what point do you give up your theories. In discussing his conversion from atheism to theism (I believe Christianity, though he never comes out and says it) in his book There is a God, Antony Flew writes:
Now it often seems to people who are not atheists as if there is no conceivable piece of evidence that wold be admitted by apparently scientific-minded dogmatic atheists to be a sufficient reason for conceding "There might be a God after all." I therefore put to my former fellow-atheists the simple central question: "What would have to occur or to have occurred to constitute for you a reason to at least consider the existence of a superior Mind?"
Obviously, this question can go both ways, and can be applied to just about any partisan disagreement, including the one at hand. With that in mind, I'll rephrase the questions I asked above:
  • If you believe that thimerosal is not a primary cause of autism, what would it take to convince you that it actually is?
  • If you believe that thimerosal is the primary cause of autism, what would it take to convince you that is not?
Note: please don't respond with something along the lines of "nothing could make me change my mind because it is obvious that my belief is correct." If that it how you feel, then you don't have anything worthwhile to contribute to this conversation and I'd prefer it if you didn't clog up the comments.

6 comments:

Jen said...

If someone could show any kind of peer-reviewed study showing that rates of autism increased with the use of thimerosal, that children who were "treated for mercury poisoning" showed any kind of real increase in functioning and/or decrease in autistic symptoms, or that the rate of autism was different between non-thimerosal exposed children and exposed children, then I would be more than willing to take a second look at my belief that thimerosal is not involved in autism in the slightest way. I love my children, but I would prefer it if no other children had to go through the struggles that they have to face on a daily basic. But until any of those things happen, I'll focus my time and energy on making their lives the best that they can be, rather than just looking for an easy thing to "blame".

Club 166 said...

The California numbers were the "evidence" that was first used to "prove" that a mercury-autism link existed. I think that is one of the reasons they used these same numbers to show that "it isn't so".

I don't think that the California numbers should have been used in the first place, therefore I don't think that they are the strongest argument against a mercury-autism link.

I do think that the sum of all available evidence yields no credible support for a mercury-autism link.

So what would convince me that there was a link?

If there were several well conducted peer reviewed studies that showed otherwise I would change my mind and become convinced (one should never change one's mind on the basis of any one study).

Joe

Wade Rankin said...

I find it curious (or maybe not so curious) that the efforts to refute vaccine or environmental hypotheses always seem to focus on one element, and only one element (e.g., thimerosal in one study, MMR in another). Many -- if not most -- of us who accept the possibility that medical science may have harmed our kids have moved beyond looking at just one culprit. Rather we focus on processes, with the understanding that different bodily insults did different harms, which have acted together. That's why I have problems with any study that looks at only the impact of a single substance, particularly when that study uses qualifiers like "primary cause."

Until we understand the processes at work, we cannot fairly assess the contributory impact of any particular factor.

That being said, I must admit I have not yet read the new thimerosal report, but I suspect it relies heavily on the unfounded myth that thimerosal has been completely eliminated from the vaccine program. And I also have to reiterate my basic distrust of the probative value epidemiology given the opportunities for result manipulation through creative survey design.

As always, Brett, nice job of fairly presenting a (still) controversial issue.

laurentius rex said...

What arrogance to quote Popper but neglect the essential paradigm of Popperian methodology which is the falsifiability of hypotheses.

I think nothing short of a brain transplant is likely to cause some folk to abandon there hold on falsehood

Maya M said...

I don't think thimerosal causes autism, but if a study shows it to cause an autism-like condition in an animal model, I'll reconsider my view.

Anonymous said...

Here's an excellent link to info that you haven't seen on the tv news http://www.huffingtonpost.com/david-kirby/pediatricians-abc-and-ce_b_83472.html

In particular, the peer review journal article in the Journal of Pediatric Neurology.

Pam