The Roots of Anti-Vaccine Insanity
Discover has an important article in its June issue by Chris Mooney on why the vaccine-autism controversy rages on, despite the fact that the supposed vaccine-autism link has been thoroughly discredited.
While I’m just inviting abuse from the BIG-PHARMA-RAPES-CHILDREN-AND-THE-GOVERNMENT-IS-COVERING-IT-UP-TOO-RON-PAUL-2012!!!!#@$#@ crowd, I suppose I should start out with exactly why we know the vaccine-autism link is bogus (or, at least, that it’s supported by ZERO evidence).
We know it’s discredited because:
* Earlier this year, a federal “vaccine court” made a definitive ruling that one of the leading vaccines-cause-autism theories (that a certain combination of vaccines triggers the disorder) is bunk.
* As mentioned in the Discover article, multiple exhaustive studies have found no link between vaccination rates and autism incidence.
* While this whole controversy was largely sparked by a 1998 paper in The Lancet, 10 of the co-authors of the original paper have retracted their claims of a link between vaccines and autism.
* Perhaps most damningly, despite the fact that the supposed culprit in vaccines, thimerosal (a mercury-based preservative), was removed from vaccines around the turn of the millenium, there has been no accompanying drop in autism rates — which there really would have to have been by about 2007. If, that is, there were any validity to the theory.
The alternative to believing this overwhelming body of scientific evidence and consensus is to believe that there is a global conspiracy, involving thousands of doctors and officials inside and outside the government, to give children autism in the pursuit of vaccine profits.
Now, I’m only giving the barest bones summary of the anti-vaccine-autism-link evidence here because I don’t expect to change the minds of the BIG-PHARMA-RAPES-CHILDREN-AND-THE-GOVERNMENT-IS-COVERING-IT-UP-TOO-RON-PAUL-2012!!!!#@$#@ crowd.
In fact, it’s that fact — that their minds are essentially impossible to change — in which I’m actually interested. How does a belief like “vaccines cause autism” come to hold such sway? And why won’t it go away?
There are a number of cognitive quirks at play here, so let me just go one-by-one and see if we can learn anything useful, below the fold…
The need for an answer
This, I think, is the cognitive problem at the base of the vaccine-autism narrative. Suddenly, it seems, there is an “epidemic” of autism. (In reality, the much more likely explanation is there is an epidemic of autism diagnoses, as the definition of autism spectrum disorders expands, public awareness grows, and special-education funding is tied to such diagnoses.) If you accept that this “epidemic” exists, though, you then need to know why.
The construction of stories, as in a causal relationship between events, is a fundamental human cognitive bias. We can’t stand not knowing why, so we make up explanations even when they’re not supported by evidence — or even when they’re patently ridiculous. Why does it not rain, killing our crops? God (or the Gods) is (are) angry. We must make a sacrifice to appease Him (or Them). We kill a goat. It rains. Cause and effect.
We can’t avoid the need for explanation; it’s how we’re built. When something disturbing happens, like an epidemic of autism, we must decide why it has happened. When it’s something truly terrible that happens to us, the need is all that much greater. A parent who sees their child afflicted with this terrible condition must know why it happened — and, perhaps even better, have someone to blame. With so little understood about autism and its causes (though, it’s becoming increasingly clear there’s a very significant genetic component), and with symptoms tending to onset around the time kids get vaccinated — well, the story writes itself.
When the evidence comes in, though, shouldn’t these folks change their minds? I understand these families’ pain. I know families with children who are autistic; my younger brother was mentally disabled. Still, facts are facts, and a bogus theory of causation isn’t going to make your life any easier day-to-day.
When all the things I mention up top have happened, isn’t it time to move on?
Unfortunately, that’s not how humans work. I explained in another post the story of Marian Keech and the Seekers. In short, Keech headed up a UFO cult in the 1950s. Earth was supposed to be destroyed, and she and her followers were supposed to be rescued by a flying saucer on December 21. The day came and went, but no destruction, no UFO. Instead of giving up their beliefs, however, most of the Seekers glommed onto a new narrative — that the Seekers’ belief had saved the Earth — and began to try to win converts.
The ones who redoubled their commitment were the ones who’d invested the most in the theory — quitting their jobs, selling their houses. The UFO not showing up created a feeling of what’s been termed “cognitive dissonance.” How could I have given up my job if there’s really no UFO? The answer their brains came up with: Because what I did saved the world!
As the Discover article goes into, the anti-vaccine activists are now a bit like the Seekers, trying to come up with alternate theories of why vaccines are to blame and trying to convert more people.
If you’re Jenny McCarthy and have spent years spreading this theory — and are, in some sense, responsible for the deaths of children who didn’t get vaccinated — you’re not about to release a public statement saying, in effect: “Oops.” You’re going to double down.
Of course, some folks barely get to cognitive dissonance, because their confirmation bias — the filtering of all information through one’s preconceptions — has prevented the new evidence from reaching their minds.
Now, those are the main effects that explain why spreaders of the vaccine-autism myth do what they do. What about the rest of us? The spreadees?
Here, I’d finger the “availability heuristic.” As defined over at Overcoming Bias: “The availability heuristic is judging the frequency or probability of an event, by the ease with which examples of the event come to mind.” We’ve discussed this one also on this blog. It’s why you get flood insurance based on whether you know someone who’s had flood damage — not based on your own actual, statistical flood risk.
Now, I’ve followed this controversy for years. I’m aware of how strong the evidence is on the pro-vaccine side. I have a publicly stated opinion that kids should get vaccinated. I know my wife agrees with both of these positions. But if I had a kid right now to bring in to get vaccinated — could I honestly say that autism risk wouldn’t be on my mind? I’d be a huge liar if I said that’d be the case. I’ve read scores of message board posts with parents claiming that their child is the one who got autism after a vaccination. I’ve seen Jenny McCarthy on TV. The idea that this is possible jumps to mind, despite any logical evidence I have to the contrary. It’s what’s available in my head. It’s a bias that pushes me.
To be clear: I would vaccinate; I encourage others to do so. But cognitive effects like this are powerful. You have to ignore them to act rationally.
Availability bias, Pt. 2
The flip side of the availability bias problem is that you don’t see many of the downsides of not vaccinating. When I consider, what’s the risk of not vaccinating, not too many examples are easily available in my brain. After all, because of the success of vaccination, not many kids get diseases like measles, mumps, or rubella in the West. We now have outbreaks of these diseases from time to time because of the pockets of non-vaccinators. But this fact is not nearly as present in the public’s mind.
It’s hard to unscare people
The problem now is that once an idea has taken hold, it’s hard to undo it: “It’s not hard to scare people,” pediatrician and leading vaccine advocate Paul Offit, who himself coinvented a vaccine, told Discover. “But it’s extremely difficult to unscare them.”
Basically, people are terrible at keeping track of whether information is true or credible once they’ve heard it. As this Washington Post piece goes into, there are a number of disturbing effects here: the first thing you hear is what you believe, and subsequent denials can reinforce the original bad information; you believe something more the more you hear it, even if it’s from the same source over and over; and your long-term memory is most susceptible to bad information (that is, you forget the correction, even if you believe the corrected information initially).
So, what to do…
With all of these factors working against those who want to promote universal vaccine usage, what’s to be done?
Well, I’d suggest three things:
* Work the availability bias: Widespread coverage of any death that would have been preventable by vaccination is a must. When people ask themselves “What’s the risk of not vaccinating?” they need to have a concrete example of someone (as like them as possible) having experienced a terrible tragedy.
* Provide an alternate story for autism: As new advances give us a better picture of what actually causes autism (again, such as the genetic component), publicize this — without reference to the false vaccine explanation.
* Simply assert that vaccinations are safe and necessary: Say it early, say it often.
Counterintuitively, the worst possible thing for public-health authorities to do would be to try to “win” the argument with the BIG-PHARMA-RAPES-CHILDREN-AND-THE-GOVERNMENT-IS-COVERING-IT-UP-TOO-RON-PAUL-2012!!!!#@$#@ crowd. These people are not movable. And the notion that there’s a “debate” only makes the public more reluctant to vaccinate.
Research should continue. If a link were ever proven, that would be extremely important information. But with zero evidence of such a link, an understanding of the cognitive factors at work here can help in combating anti-vaccine hysteria.