Vaccination, Confirmation Bias, and Knowing Your Audience


"When men wish to construct or support a theory, how they torture facts into their service!"

Even in 1852, psychologists like Charles Mackay, who wrote those words in his book Extraordinary Popular Delusions and the Madness of Crowds, were well aware of the dangers of confirmation bias.

I was reminded of the pervasiveness of this cognitive bias last weekend during a visit to GlaxoSmithKline's vaccine distribution facility in Marietta, Pennsylvania. Confirmation bias is as dangerous in 2010 as it was in 1852.

I was invited by David Wescott to join a group of bloggers for an event at GSK's facility during which they would discuss the importance of adult vaccination, and I agreed to participate. My travel, accommodations and food were covered by GlaxoSmithKline. There was no explicit or implicit expectation that I'd write about the trip, and they have not reviewed this post. (Quite an impressive release of control for a multinational pharmaceutical corporation!)

As a science blogger, it wasn't exactly clear why I was included, as science bloggers generally already "get it." We know that vaccination is important, and we often write about it. That public health is a bit beyond the scope of this particular science blog only further served to confuse me. Then I landed in Philadelphia and arrived at the hotel to meet up with David and the other invited bloggers. I found myself surrounded by a relatively diverse group of intelligent bloggers...but, well, they were all mom bloggers, and all relatively local. Why did they fly me all the way out from LA? Why was I there? I still couldn't figure it out.

The next morning, after the two hour ride to Marietta (during which I observed that the changing of the leaves during autumn is NOT a myth!) the program started. It was then that I finally understood why I was there.

I don't write about health, or vaccines, I don't have a family, and I already understand the importance of vaccination. But I do write about the mind. And while all the women were watching the presentations on adult vaccination, I was watching them. At one point, the speakers were discussing the importance of getting inoculated each year against the influenza virus. I don't mean to single anyone out, but one comment was particularly striking: "I've never gotten the flu vaccine, and I've never gotten the flu." As if to suggest that there is no real reason she should have to worry about the flu virus. The very same flu virus that evolves resistance to our vaccinations so rapidly that new vaccine formulas need to be developed each year. The same flu that kills thousands in this country each year. "How they torture facts into their service," indeed.

The thing is, though, that this sentiment, which betrays a certain misunderstanding of epidemiology, statistics, and biology, was not uttered by an anti-vaccination wingnut praying at the altar of Jenny McCarthy. The woman vaccinates her children! She gets it! She is an unfortunate victim - not of anti-vaccination propaganda or the so-called "balanced" journalism - but of the cognitive biases built into her own mind.

Consider a group of people in a coin-flipping tournament. If someone wins a coin flip, they stay in the game. If they lose, they're out. At the end of fifty rounds of coin-flipping, there will be one person left, who will have won the tournament. She will have won the coin-flip fifty times in a row. But there is nothing special about her. When it comes to the fifty-first coin flip, she still has an equal probability of winning or losing. But our minds aren't really equipped to understand this kind of probability.

That brings me to my second observation. For a corporation that depends on communicating science to the public, they did a terrible job of it! For a certified card-carrying data-whore like myself, the Powerpoint presentations (which broke every. single. rule. of effective presentations. I highly recommend that they hire my friend Les Posen to teach them how to present properly) did not have enough detail. They would present some statistic, but without the level of detail required for me to make any real sense of the data. I will grant that I was not the intended audience of the talk, so I will forgive them their lack of error bars and missing p-values. For a general audience without a scientific data-driven background, the presentation was even more useless! It was all statistics, bar graphs, and numbers. If you're going to communicate science to a general audience (and I'd like to think that I know a thing or two about communicating science to a general audience), you need to engage them emotionally. You need to tell a story, not drown them in statistics. The presenter might say something like, "Last year, three gazillion people died because they were not vaccinated against a Terrible Disease That Kills People In Gruesome Ways But Which We Could Eradicate In Less Than A Decade If Everyone Would Just Get Vaccinated." Everyone would agree that this is a Bad Thing, at least. More likely, it is a Terrible, Horrible, No Good, Very Bad Thing.

But the human mind is not capable of really understanding the magnitude of a gazillion. To us, a gazillion and fifty thousand and twenty thousand aren't really so different. For that matter, neither are twelve and sixteen. That is because as the magnitude of a number increases, the specificity of our mental representation of that number decreases. Put another way, as the magnitude of a number increases, the margin of error in forming an accurate mental representation of that number increases as well. This is also true for other animals, like monkeys and rats and fish.


Remember this study?

Giving us incidence and death rates and other such statistics doesn't really get the job done. It doesn't communicate what they want it to. Nor will glossy pamphlets (like the one they gave me) featuring Mia Hamm telling us to get vaccinated. What will get the job done is story-telling, appealing to emotion, and utilizing accessible analogies. Instead of telling us how many gazillions died last year, tell us how many airplanes full of people, or how many football stadiums full of people died last year.

The people who work on developing vaccines put years and years of effort into developing their products. And corporations like GSK spend millions of dollars funding those efforts. It is a shame that they can't communicate the critical importance of vaccination in a more effective way.

As we left the facility, I turned to David and quietly asked him, "do companies like this have any psychologists in their communications departments?" "No," he said, "they're all PR and marketing people."

Perhaps they should consider hiring on a cognitive psychologist or two.

Addendum: It occurs to me that GSK's legal department must carefully scrutinize any sort of public communication, and perhaps the presenters we interacted with were severely restricted in terms of content and delivery style. That said, there must be a way to communicate science in a more robust way that still falls within the confines of legal acceptability. An interesting question to ponder.

Here's the disclaimer again: My travel, accommodations and food were covered by GlaxoSmithKline. There was no explicit or implicit expectation that I'd write about the trip, and they have not reviewed this post.

Learn more about vaccines, courtesy of our friends at Science-Based Medicine.

Posts from some of the other bloggers at the event:
Mom to the Screaming Masses

Coverage from the official GSK blog: More Than Medicine.

Image source.

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I read one of the mommy blogs you linked. Very, very encouraging. Especially the comments section.
But your appraisal of the psychology of effective communication was powerfully demonstrated. The blogger was extremely impressed by the whole process from development to approval. She describes the level of meticulous detail by how she observed an entire lot being discarded because of a labeling problem.
In the comments, the personal stories of dealing with H1N1, babies dying of pertussis, older family members who required iron lungs from contracting polio, etc are definitely made the case for vaccines. Probably more than dry numbers.

Very encouraging to read all this from non-scientists who truly understand the importance of vaccination,

By laursaurus (not verified) on 04 Nov 2010 #permalink

I think all this pushing of flu vaccines is counter-productive: we have people failing to immunise their children against genuinely dangerous diseases and then there's all this flu-related hysteria which seems to be aimed at confirming them in their scepticism through the not-very-credible insistance that they submit to a commercially-driven goldmine of half-arsed vaccination against a virus which carries almost no more than the insignificant risk of having to lose 4 days off work and which will evolve in just a few months into a virus which your recent immunisation will fail to cover anyway.

If I were GSK I would be very excited about the prospect of signing-up 7 billion people to the idea of paying twice a year for an almost completely pointless vaccination.
And if I were an anti-science anti-vaccinator I would regard this as a godsend for me to get my message out there.

Additionally, the PR-driven hysteria surrounding H1N1 resulted in vaccines being rushed onto market without proper testing with the inevitable result that some had to be recalled due to unforeseen side-effects (on children! Tabloids loved that!) and governments wasted bucketloads of tax$$$ over-stocking.
That didn't help at all for flu vaccine credibility.

By Vince Whirlwind (not verified) on 04 Nov 2010 #permalink

I used to work in the sales division of GSK. I can confirm your suspicions that that it, and all the other pharmaceutical companies, have a public face (and strategic mission) conceived and executed by their marketing departments, and then constrained by their legal departments.

Since about ten years ago, all marketing materials are rigorously sanitized of any intellectual interest by the legal department, especially the PowerPoint slide presentations - which must be presented as is and in entirety, from start to finish.

Speakers can go off topic or use their own slides only if an attendee asks a specific unsolicited question. It makes for dreadful presentations if audience members have not learned to interrupt with unsolicited questions. ;D

You can't blame pharma, though - look at the huge fines levied on individual companies for promotion off-label, etc. A number of pharma companies have done some unethical things, but it is also true that the FDA harasses them over truly trivial matters, and sometimes for no apparent reason whatsoever except the malice of an individual committee member.

It is a very antagonistic relationship - the notion of denialists that pharma and the FDA are somehow coconspirators is pretty absurd to anyone who has worked in the industry.

By Gingerbaker (not verified) on 04 Nov 2010 #permalink

"If I were GSK I would be very excited about the prospect of signing-up 7 billion people to the idea of paying twice a year for an almost completely pointless vaccination. "

In its heyday, the relative contribution of vaccine sales to GSK's bottom line was so small as to be not even worth mentioning at sales meetings. Vaccine production is cost-intensive and generally has a very small profit margin.

There are very few pharma companies still making vaccines these days.

By Gingerbaker (not verified) on 04 Nov 2010 #permalink

Incredible discussion on how to communicate science to a general audience. I look forward to more discussion about successful communication.

I also think you may consider doing a post for journalists about how to prevent making gruesome errors in reporting.

Jason, ta for the referenced and link. You'll be interested to know that in my presentation skills workshops for scientists I have a very early section which serves to justify why scientists need to come to terms with how audiences are receiving information nowadays: through TV, movies, YouTube, and the 24/7 news cycle. One clip I show comes from Diane Sawyer's ABC current affairs program where she discusses the American Paediatric Association's review of the literature on Autism and its treatment. Instead of going into detail, she cuts to an interview with Jenny McCarthy who implies scientists to listen to her anecdotal evidence. Sawyer then cuts back and says if you want more information especially from scientists go to the ABC website blog.

That always gets a chuckle from my audiences, because the emphasis in the story is the celebrity over the scientist. But that what presenters in the science are up against in 2010.