Humans are not entirely rational creatures. We all know this from daily experience, although we happily assume that we are more rational than other people (which is just one of our irrationalities). We are motivated by the need for meaning, and for esteem. We tend to pick sides, and then invest our egos in that side, defending it at all costs.

We are also motivated by the need for simplicity and control. The world is a very complex place, overwhelmingly so. Therefore we need to simplify it in our minds, so that we can deal with it. We use schematics, and categories, and rules of thumb to impose a manageable order on the chaos of reality. These devices are quite adaptive, as long as we realize that they are just that – human devices to approximate reality in a way we can handle.

But too often we confuse our simplistic models of reality with reality. Further, we like our morality plays to be black and white. The villains are villains, without redeeming qualities. The good guys wear white and have no major flaws (nothing beyond an endearing quirk). The ambiguities and gray of the world make us feel uncomfortable. This tendency, by the way, leads to certain logical fallacies, such as poisoning the well. If Hitler believed something, and everything Hitler did was bad, then that belief must also be bad.

We can see this need for moral clarity and scientific simplicity at work in the anti-vaccine movement. Their core belief is that vaccines are not safe, that they are causing harm to our children. They are incorrect in this belief, but that is the bedrock of their movement.

They are not satisfied with this notion that vaccines are not safe, however. Every other belief about vaccines must also be in line with their core belief. They are particularly intolerant of complexity or moral ambiguity. Therefore they have convinced themselves that not only are vaccines not safe, they don’t work. Further, the diseases they treat are not that bad. They believe those who promote vaccines are also selfish and evil, morally compromised liars (they happily portray us as baby-eaters). They cannot wrap their heads around the notion that perhaps well-informed people who mean well disagree with them.

The anti-vaccine echo-chamber exists in a cartoon world of cardboard villains, dark conspiracies, and white-hatted heroes (a role they reserve for themselves), where the science all lines up in their favor, without the slightest compromise or ambiguity.

Before someone tries to turn this back on the scientific community, I do not think the same applies to the defenders of science-based vaccines. We admit that vaccines have risks, and harm does rarely occur. But the benefits outweigh the risks. We acknowledge that pharmaceutical companies care mainly about their own profit (they are corporations, and that’s what they do), and they need to be carefully regulated to protect the public interest. We acknowledge that, while vaccines work, they are not perfect. The flu vaccine in particular is very problematic, particularly matching the strains each year with the ones that are likely to hit in flu season. But still, we eke out more benefit than harm.

We also acknowledge that the anti-vaccine community is a diverse group. And while I suspect there are some charlatans and con artists thriving in their midst, most anti-vaccinationists appear to be sincere parents who are just trying to do their best for their children. They are simply misinformed, by a well-funded campaign of scientifically complicated misinformation. Many are caught up in the anti-vaccine echo-chamber, subject to group dynamics and all that implies.

Just take a look at the Age of Autism blog – a sociologist could make a career out of studying the comments alone. A recent article at AoA is the perfect example of the need for simplicity. David Burd writes Death by Flu, The Big Lie Crumbles. The title itself reveals much – flu is not that bad, and those who say it is are lying. Nice moral clarity.

Burd is shocked (shocked!) to discover that the number of flu deaths each year is estimated by the CDC. He writes:

“CDC makes it abundantly clear these 3K to 49K “flu-associated” deaths are not actually counted, but are instead estimates generated from computer models that hypothetically link such as pneumonia deaths to those theoretically having a prior case of influenza (with the influenza long gone).

and

Subtracting 105 from 311 we see a documented count of 206 adult flu-associated deaths. It will be interesting to see what CDC’s computer-model finally conjures up as the final 2010-2011 “flu-associated” death tally.

Interestingly, Burd glosses over an important fact that he relates – the CDC does make it abundantly clear what methods they use. They have complete transparency. Using various methods they, and other researchers, estimate the number of flu-associated deaths in the US as between 3 thousand and 49 thousand each year. They estimate the number for a very good reason – the surveillance mechanisms in place do not allow for a direct counting. Most people who come down with the flu do not undergo laboratory testing to confirm that they actually have the flu. The diagnosis is often made based upon clinical symptoms. We also know from case histories that some people will develop complications from the flu, like a secondary pneumonia, which will be the ultimate cause of death.

The goal of the CDC estimate is to figure out, as closely as possible, how many excess deaths are due to the flu – how many people died who otherwise would not have if not for the flu.

Burd makes no substantive analysis of the methods used by the CDC and other researchers. Nor does he attempt to make an alternate estimate. He simply counts the laboratory-confirmed cases as if this is the “true” number. He makes no mention of the fact that most cases of flu are not examined with a laboratory test, and therefore this number is likely to be a gross underestimate – by orders of magnitude.

He takes this pseudoscience further by comparing US and Canada laboratory-confirmed cases:

Summing up, while Americans are coerced, cajoled, or required in school and health institutions to undergo the dangers of flu shots, our Canadian neighbors overwhelmingly reject them, and the last five years Canada has averaged but a single (non-comorbidity) flu-associated pediatric death, while the U.S. toll rises ever higher.

He neglects to mention that the US has a higher population than Canada, and that differences in surveillance methods would also need to be taken into consideration. The comparison, in other words, is absurdly useless. While decrying the methods used by the CDC to estimate flu deaths, Burd abuses completely inaccurate numbers for his propaganda purposes.

But he has fed the echo-chamber another round of reassuring simplicity and moral clarity – not only is the flu vaccine unsafe, the flu is not that bad a disease anyway, and those who are pushing the vaccine are liars.

Burd makes no attempt at due diligence or respectable scholarship. He does not try to understand the CDC methods. It’s enough that he has hit upon a fable that suits the propaganda agenda of AoA.

Nor is AoA an isolated example – it is more the rule than the exception (although it is an extreme example). We see the same thing at the DiscoTute with respect to evolution, or on any news outlet with a political skew (which essentially means all of them, although to varying degrees). This phenomenon is widespread (as you would expect for anything that derives from basic human nature), which is why it is important not to rely on any single source of information. It is helpful to look for the other side to the story, assume that there is probably more complexity to an issue than is at first apparent, and to be vigilant about the need for simplicity and clarity in our own thinking.