The only real scientific mystery about vaccines is why so many people buy into the deadly pseudoscience of vaccine denial and put their kids -- and yours -- at risk of catching ancient, vanquished, deadly diseases.
In this video, Hank Green explores the cognitive science of vaccine denial -- how and why denialism takes hold.
In psychology, the search for these explanations is called "Explanatory Attribution" and different people have different "explanatory styles". Some people are more prone to blame themselves, while others search for an external event to blame. But one thing is clear: we are very bad at not blaming anything. It's not surprising that parents of children with autism, especially parents who notice a sudden loss of previous development, will search for a possible cause. And when the most significant recent event in the health of the child was a vaccination, as can be said for many moments in the life of a young American, we might identify that as a potential cause and deem that link worthy of further examination.
Now this, is completely logical. The problem is that over a dozen peer-reviewed papers have found no correlation between autism and the MMR vaccine, or any other vaccine for that matter. And yet, when you Google vaccines and autism, a fair number of the results claim that there is a link between the two, and that that link is being covered up either by the government or by big corporations. A parent, already experiencing frustration with the medical community's inability to tell them why this thing has happened to their child, will, on the internet, find a vibrant community of similarly frustrated people who share their values and experiences. These communities are full of anecdotes that draw connections between vaccines and autism. And so, unsurprisingly, some people become convinced that they have found the reason for their child's disability.
Once their mind has been made up, confirmation bias sets in. Confirmation bias is simply our tendency to more readily, and with less scrutiny, accept information, anecdotes, and world views that confirm our existing beliefs. And, again, it is a completely normal thing that every person does. Indeed, trying to convince someone that a previously held belief is incorrect has been proven to actually increase their affinity for that idea. And so a community is born, and the safety of vaccines is called into question. And once the procedure for getting a vaccine goes from the doctor telling you that it is now time for a vaccine -- and 99% of parents agreeing because that person went through medical school -- to it being a question to ponder, vaccination rates will go down.
The science of anti-vaccination [Kottke]