Statistics and manipulation of the ignoramuses (contd.)

[Previously in the series]

Thanks, Ob--- er, Jenny McCarthy!

You probably have heard the phrase "Correlation does not imply causation." All it is supposed to mean is that if two things seem correlated that is not supposed imply that one is the cause of the other. To be clear, if two things correlate well, we are entirely logical in suspecting that there may be a causal dependency. The error is in asserting that because there was a strong correlation one causes the other, and equally the specific direction of the causation. In other words, it'd be wrong to conclude that autism caused an increase in organic food sales, just as it is to conclude that the rise in organic food sales caused an increase in autism rates.
Now, is it possible that one did cause the other?  Yes.  The key however, is that the correlation does not establish it. One would, for example, have to conduct experiments with proper control groups and find a statistically significant set of results.

The anti-vaxxers and the lazy, accommodationist media obsessed with balance to the point of false equivalence, and beyond, have succeeded in perpetrating the myth that vaccines, and particularly the use of thimerosal in vaccines have contributed to the rise in autism rates.

I have mentioned this in the past, and directed my not inconsiderable digital ire at the mainstream protagonists like Bill Maher, Jenny McCarthy and Michele Bachmann.

But I left out the weasel.

"We've seen just a skyrocketing autism rate. Some people are suspicious that it's connected to the vaccines. This person included. The science right now is inconclusive, but we have to research it." —Barack Obama, Pennsylvania Rally, April 21, 2008.

(Liberals can take solace in the fact that McCain, his opponent in that election was equally wingnutty on the matter.

"It's indisputable that (autism) is on the rise among children, the question is what's causing it. And we go back and forth and there's strong evidence that indicates it's got to do with a preservative in vaccines." —John McCain, Texas town hall meeting, February 29, 2008.)

Here's the thing, though.  Suppose that use of thimerosal in vaccines was, as suspected, responsible for increase in autism rates. Then it'd stand to reason that were thimerosal not used, the rate of increase would be arrested, and even reversed. This is not what we find, though. Autism cases continue to rise.

So what's the harm in a few bimbos sounding the wrong alarm? Well, for one thing, it takes attention away from research and policy to find the real cause, and it leads to preventable outbreaks of diseases by people choosing not to vaccinate.